Shrockbumper broke

So not too far into the Nexterra/UNYX Old Flordia Rd run on Saturday my clutch died and I had to get towed out of the way of the trail...The recovery pointso n my Shrock bumper where used and the bolts the go in the front of the frame horns ripped clean out! They were the bolts supplied with the bumper...I dont understand...and the bumper bent downwards...Another Nexterra member almost had the saem thing happen to him while getting towed but his horns started to bow and looked like the bolts were bending out...Why is htis happening? any ideas...by the way I believe my frame horns are destroyed now and I may have to go the welding route...Not happy

Wait a second. Do you mean that the frame on the truck itself ripped and the bumper did not?

no...not quite...when he was being pulled, the bumper itself bent downwards a bit and then the grade 10 or whatever bolts that attach the bumper to the front of the frame horns stripped right out of horns so it was only attached by the side bolts...

How bout a pic or two to help illustrate the issue....

I wil lpost as soon as I get my X back from the dealer in Pittsfeild. Right now for me that is 2 hours away some I will ahve to wait since I am not driving up there jsut to take pics :p I have a few on my camera phone but dont know how to upload them. For now jsut think of it as if the side bolts are connected and the front ones arent. And on top of the the bumper is bent downwards towards the ground a little...well more than a little...

It sounds like the damage is to the ends of the frame horns...that the bumper was pulled down hard enough to make the bolts that go into the ends of the horns rip free.

IE: the horns broke, so the bolts came out when the bumper pulled on them.

I have trouble imagining this, as the three points per horn are kind of tied together, and its a 3/8" steel plate connecting them....so if one moves, they should ALL be moving...

One thing I can think of that would allow that kind of independance is if the holes were slotted, and then not adequately tightened to prevent slippage?

There's no way the 3/8" plate bent with a pull along its length/strongest orientation...so a pivot relative to the frame is all that can occur.

What's really odd is that those end points should not have had that much stress on them relative to the other points, in the first place on a recovery.

Unless, the frame ends themselves buckled inboard of the bumper, as in between the bumper, and the frame....

That would let the bumper fold down as described, but wouldn't explain the frame horn ends ripping independantly of other mountig point damage....

Those pics should help a lot...I'm guessing we'll see ripped frame horn ends based upon the above...and slots on the bumper or frame rail where the bumper was attached....and/or, a structural failure of the frame itself, between the bumper and the rest of the frame.

At least it will be interesting from a forensic stand point.

Ok...no damage to the frame horns from what I can see at all. Let me try one more time...I guess it is harder than I thoguth to imagine this. Think of your ordinary Shrockworks bumper. Ok the front bolts got ripped out of the threads (no damage to the horns except maybe teh threads inside but I didnt have a chance to pull the skid off and look :p ). Now imagine the bumper pulled forward enough so that there is about 1/4" or so of space between the front mounting points and the end of the frame horn itself (so its just liek it was mounted to far forward) Now picture that but the bumper tilted in a downwards position. Again it probably is hard to picture but there was no visible damamge the the frame. The only thing Icould think of is that I got the bumper for the 2" BL version. Becasue fo this the mounting holes on the sides are slightly more oval/longer than regular ones would be. If they weren't tightened down enough then i could see how it may have happened. But they were tightened almost as tight as the shifter is . I don't see how there could have been that much play with the bumper.

OK - now its more confusing....the frame is intact, and the bolts came out...?

You say the bumper is tilted down, but not why or from what points....so it is hard to picture how it tilts w/o the frame horns tilting...unless you bent the bumper itself, which sounds impossible in that plane....

Maybe the bolts failed, letting the mounts break free?

We really need those pics.

So it's not the bumper that broke, it's the bolts that stripped out? What did the threads on the bolts look like? I have not seen the horns on the Xterra, but there are many ways to fix the holes without needing to weld. The sad part is it sounds like the bumper is now deformed. I hope it matches back up.

Just curious, what were the bolts torqued to? I don't know if Shrock has suggested torque specs, but I would treat it like a tow hitch (since it is a recovery point) and torque them down to no less than 70ft. lbs. or so.

Also, when you were being pulled off the trail (or any past recoveries using the bumper) were you being jerked? If the bolts were not tight the extra jerking could have weakened the threads.

i'll let him anwser since its his truck, but from my point of view, the recovery didn't seem to involve any jerking, at night, a group of us had to push the truck backwards out of the trail, we were on the shrock bumper pushing, and it would pivot up and down, we stayed clear incase it let go and dropped on our feet, but it was strange, ok that was my point of view from pushing on the front

Not sure what happened from the description....

There is almost no force on the bumper itself when pulling from the recovery points...they bolt directly back to the frame through a piece of 3/8" plate on edge. No way it can bend in that orientation. If the side bolts aren't tightened fully, most of the load goes to the horn ends. If the frame horn end let go on one side only, that would put a torsional (twisting) load on the bumper though....

Unfortunately the frames on these trucks in this area are not very strong. Problems seem to be very rare, but there is something you can do to prevent it. There are two extra round holes per side in the bumper mounting brackets. Drilling these holes all the way through the frame with a 3/8" bit and using 3/8" bolts all the way through the frame will take most of the load off the horn ends and give two additional un-slotted attachment points. These holes are positioned toward the edge of the frame so that crushing the frame when tightening the bolts is not an issue.

I just read this part. If the bumper was moving while pushing on it, the bolts twere extremely loose...that would do it.

Regardless of why, give me a call cobain913 and I'll work with you to get you a usable bumper again for minimal expense.

Jim,

Slightly unrelated, are there any torque specs you suggest for the bumpers?

The instructions for the 1st gen state 50-55 ft-lbs. The bumper for your 2005 will be different since it has four M12 bolts vs the three M10 on the 1st gen.

This sounds like the threads simply pulled out of the ends of the frame horns and the bumper rotated down a bit. If the threads did pull out the ends, it *would* rotate down and point downward some bec the side bolt holes are slotted. Are you sure the bumper is bent and not just pointing down? It certainly doesn't sound like the bumper "broke" ...

No Jim. I don't thin the bumper broke but the bolts certainly got puleld out of the frame horns...The thread on the bolts looked ok but there was al ittle bit of metal surrounding them...No deformaty to the threads on the bolt themselves though. The bumper itself I don't think bent either. I am jsut concerend about how I am goign to get the bumper in its correct position again if the frame horn threads are stripped. The bumper is definately tilting down becasue as mud4x4 said, when they guys were pushing me it would move up and down...This may have been since the bumper was puleld forward and out and gave it the play there. I will check to see if the bolts on the sides were loosened when I go to pick it up. If this is the case then there maybe damage all around on the threads to my frame horns. But trust me...Those bolts were tightened down like hell.

We can speculate all day about what could/mighthave/ think happened... We really need to see the pics of the frame horns/ shrock mounting points to even begin to speculate. For all we know he was using a 12k winch and ripped the bugger off at the bolts.... No offense but before shrock should be brought into this, the situation needs to be evaluated better than just hear say. Just me being a cynic (sp?) I dont mean to insult but ive worked in retail too... and you cant really trust what the customer says all the time.

I can also add, since I was the one pulling him, there was no jerking involved. We were using a tow strap, not a chain. All the sudden, people yelled, "Stop," and the bumper was pulled down.

On Jim's bumper, the front bolts pulled out of the frame horn.

As those of you who were there know, I used my winch more times than I can count that day. My Shrock bumper didn't move. I also banged the hell out of it climbing up those two rock faces...still it did not move.

"Those bolts were tightened down like hell."

Still just speculating, but evertightened bolts are as bad as loose one. If you tighten them enough, it only takes just a bit more force to strip out or break them.

If you send some pics, I'll try to help you come up with a plan. If it works out like you said, bolts pulled out and bumper and frame arent bent, it shouldnt be hard to get rollong again.

Hey Jim. Why so low?

Can't he just torque the ever-living sh!t out of them?

So, it sounds like the factory threads in the frame stripped out. How does that make the bumper broken? The threads in the frame aren't that strong, that's why a lot of people just drill through and put longer bolts in with nuts on the end. Maybe it's time you do that?

I'm guessing so and that is probably going to be the plan...unless i decide to weld the bumper higher to correct the hieght (which I know doesn't do anyhting for approach angle yada yada yada becasue of the frame horns remaining the same height). Unfortunately I can't ahve pics for anyone until the dealer has fixed my clutch situation. And I don't feel liek driving 2 hours out of state jsut to go take a few pics, sorry! But there is nothing to see...It's jsut the bolts ripped out of the horns and the bumper is not bent but it just got titled down significantly...why is this so hard so visualize? maybe its easier for everyone who was there becasue they all saw it but for those of you who did am I explaining it differently thaan it is?

See your thread title... All im saying is you jumped to conclusions without first finding out the facts. Now everyone drew their own conclusions with the sporatic and conflicting information you provided. You need to deal directly with shrock to find out what happend and when you reach a definitive "My bumper really did break" then you can post something claiming so. Its obvious shrock wants to work with you on this.

From what I saw, the bolts broke. The top bolts on the horn broke and the welded in nuts on the front of the horns (actually that box part) pulled out of the frame horns. I don't think the bumper broke at all. Stange thing is, I have pulled like hell on that front bumper. Probably 20 times that day alone, with no problems. I wasn't pulling you all that hard. At least it didn't seem so.

Sounds to me like the bolts sheared. Like Jim said, possibly from over torquing. Use the torque specs, and a little thread locker.
A pet peeve of mine: Hardware Gorillas; people who think tighter is always better. Ironicly I have "gorilla proof" hex wrenches.

Daggerdoggie: probably from accumulated fatigue on the metal

DBAX: That is the coolest graemlin thing ever.

that is kinda cool...but again dont post for pics....i said you wont get them until i get my X back in working condition...not driving 2 hours out of my way for pics...so dont post for the pics anymore please. maybe i could have made the title a little different...sorry but something broke. The bolts didnt break from what i saw...no shearing action. They jsut came clean out of the horns and took some metal with them. How about this...we leave the thread alone and I am guessing around Thursday I wil lbe getting my X back from the shop (Earliest!) By then if I have it back in CT that day I will take pics of the bumper and frame as is and you guys can come to your conclusion as to what happeend then.

Being there, seeing the situation in detail both when it happened and the next day when there was more time to examine it I have a couple--non-important--things to add here....#1--Dom(cobain913) has no ill intent here when he says his bumper "broke"...he doesn't mean the bumper snapped in half or anything like that....he just meant that something went wrong and the bumper is not operating the way it was intended...can't imagine there was any blame implied...#2--Jim...to quote you "This sounds like the threads simply pulled out of the ends of the frame horns and the bumper rotated down a bit. If the threads did pull out the ends, it *would* rotate down and point downward some bec the side bolt holes are slotted." This is EXACTLY what I believe happened...there was no twisting or damage to the frame horns, there was no obvious movement or damage to the side bolts and it simply looked as if the bolts to the front of the frame horns had pull out of their holes, doing some damage to the bolts on their way out....the likely repair I would imagine--though other more knowlegable(pretty much 99% of the people out there) people may have a better solution--would be to redrill the holes, use the next bolt size up, and confirm the torque setting...

I didn't realize their was a torque spec on the bumper. I read the directions and everything when I installed it. Maybe I just overlooked. Anyways, I just used an impact on my bolts. I imagine they are pretty snug on their... I hope not too tight now.

OK - it sounds like the frame horn bolt strip from overtightening, and the subsequent pivoting of the slotted rail bolt points is it.

The stock parts are a bit delicate, and just like putting together IKEA furniture, if you use too much force, the stock parts can't take it, and can break, strip, warp, etc.

That's one of the reasons I didn't use the stock frame horn end bolt holes when I lifted my winch bumper, I welded an "L" on top of the horns, and bolted through that, and as the horns themselves were a bit wimpy, I also welded a brace between the horns to shore them up, especially against torque loading from potential off angle winch loads, etc.

Our confusion here is that articulation is important, even in conversation.



Saying something "broke" implies that it, well, broke.

If what was meant by "it broke" is that "What it's attached to broke", that's fine, its not like Cobain is famous for clarity of speech....hell, most of the time he gets kudo's for performing opposable thumb and forefinger tricks.



By process of elimination, and reliable eye witnesses, we figured out what he would have said had he been better at this sort of thing.



The morals here are:

To take the pics BEFORE travelling 2 hours away..

...and to take it easy on stock mounting points, they were not designed to take non-stock forces.

And to add to TJ's...

Use freaking loctite on important bolts. The bolts may not have stripped out; they could have just simply loosened up over time. There shouldn't ever be any force in the sideways direction; at least not nearly enough to strip out the bolts, considering they're perpendicular to the bumper... My guess is they loosened up a bit, 'cause there wasn't a lock washer and/or loctite involved.

haha unfortunately this is true...I do ahve one pic on my phone that is a shot of the frame horn but i dont know how to upload it onto my computer...so unless somone can tell me how to do this I'm SOL...I have an LG phone (the one with the sxivel camer on top) and Verizon service...I am really bad with figuring this stuff out so if you want to tell me quick i can get that pic up

Same kind of thing happen to a couple of owners of ARB bumper owners who winch on 2K’s. Ned being one of the ones I remember, I saw 1st hand what happen...his bolts where torque down properly yet the frame horn holes ended up elongated after a normal pull. He eventually went with the extra bolts on each side like Jim suggested and also welded on a L type bracket on top and did’nt have any problems after that.

When I put my winch on my ARB I just went with the extra bolts on each side and haven’t had any problems but without them the bumper is not secure enough for pulling IMO.

Brian

Do we need to put in more than the 6 bolts if we winch/pull with the shrock bumper? I thought about drilling 2 more holes for 8 bolts total through the frame horns.

You don't want to do that.

suspect2 i wouldn't do that, it what designed to have six bolts and not 8 and it was also designed to have winches inside and pull stuff. If it couldn't, the people at Shrockworks would add some bolts or modify it if it was a problem. If ur bumper came out of the car then it was prollly put on wrong.

JUst follow the directions!

I don't think there's any harm in adding one hole per horn,.... once the bumper is mounted with the end horn bolt, and the slotted side bolts, there is an extra hole on the frame mounts of the bumper that isn't slotted....drilling a hole through the frame, through those holes, would lock the mount so it would not pivot.

I believe that was always an optional mounting point, so Jim already has given the option if desired.

I'm not sure if the frame mounts on every year's bumper have those extra mounting holes or not, but, if you have them, seems to be an easy add-on...and, if not, you could always just drill through the bumper and the frame, and then slide a bolt all the way across.

I haven't done this, but then again, I like torque wrenches, and I appreciate the concept that if you torque something past the strength of the thread system, it can strip/be weaker than if you were more gentle....more isn't always better.



I also like lock-tite, etc....so my shit don't fall off.

is it ok if u dont do this

cause when i ordered my bumper i asked the guy on the phone if the bumper came with everything it needed, and he claimed it did and it would come with 6 bolts and all that stuff, but he claimed that is all u need.

You look at it like this. Most are running 6 bolts and it's not like you have hear bunches of horror stories about the bumpers ripping off. So I am sure 6 is fine for most applications. On the other hand, drilling two holes and buying two bolts isn't a big deal, so why not do it for the extra security?

As others have said, over tightening is a bad thing. This is the reason there are torque specs for things. Stressing threads are just as bad as not tightening the bolt/nut.

My number of 70ft lbs comes from the typical torque specs of trailer hitches, not just on X's but most vehicles.

Adding bolts may not be a solution. You could make it 8, 10, or 12 and then you have frame horns like swiss cheese, and just as strong. There can also be a lot of torsional stress and upwards stress from hitting rocks with the bumper. Which I have done a fair amount.


As you can see, I even bent my bumper at the hole where you can reach in to move the cluch on the winch. Mine has held up fine, and I have used the winch many times as well as the tow points. Following torque specs is important. when you torque a bolt, you are stretching it to a point, when you over torque it you strech it too much and weaken it.

Sometimes, things just break on the trails.

NICE PIC!!!!!

Hey guys, late chiming in but I was the other person that had problems that day with the bumper mounting points. The reason the bumper tiltd without doing damage to the other 2 bolts is because the other bolt holes are slotted. I have a pic. Though the bolts didn't pull out like Cobain's, it was on it's way. I plan on banging the warped matal back flush and adding more bolts like Jim said. I think why winching doesn't do the damage but being pulled does is the load is more centered on the bumper when winched (load is spread more evenly) where being pulled from one recovery point puts all the pretty much load on one side. I winched myself quite a few times later that day and no further damage. I had a TJM on my Frontier and used 1 recovery point and no damage what so ever.

Another late chime in - The frame horn threads are not that strong. In the course of mounting my Shrockworks bumper, I tightened and loosened them probably half a dozen times trying to get things lined up perfect (I'm anal). In the course of doing so, I stripped out 1 side. I wasn't even torquing them that hard - those threads are really weak. My solution was to drill the hole out a smidge and put a nut on the back side - there is just enough room to slide a nut up behind there (at least on my frame horns there was). The threads are weak, so be careful.

i recommend if you add one more bolt or maybe even two that you sleave the frame. box it so it doesn't crush. i did this when i lifted my ARB for the 2"BL.

Can you explain what you mean by "sleave the frame"??

Those threads are weak. After I had taken off/put on my Shrock bumper numerous times, I got the bolt on the frame horn end driver's side crossthreaded because the threads had gotten so thin and I haven't fixed it yet.

That's a good idea about the nut - I'm going to see if there's enough space on my Frontier to fit a nut up in there. I'd like to still do the "L" brace on top of the frame horn end like TJ did, but damnit I don't want to take off the bumper again!

-Bp

I believe that is when you cut some tubing and weld it into the holes you drill through the frame horns. Stormtrooper/The BN Guy over on NOR also did this when he raised his bumper to match his body lift:

Shrockworks Bumper Relocation After Body Lift

This is another thing I might do if/when I take my Shrock bumper off.
Right now I just have two pieces of 1/4" thick steel 2" wide by 6" long as a backing for the bolts I drilled through:



-Bp

Exactly

nice job on the frontier. very clean.

Ok hate to be the one to mention this but....
If you sleeve your frame in that spot it looks like you will be reenforcing the Crumple Zone. Not exactly a good Idea, that could cause your air bag to prematurely deploy in an accident. Or deploy when it normaly would not have. The sensor for the air bag requires so much "shock" to set it off. If the frame doesent crumple in a lower speed accident you could inturn set of the air bag.

I dont claim to be an expert on this but it is just an Idea. Personaly I wouldn't screw with the acordian looking part of the "frame horn".

As a matter of fact Im gonna ask my Body shop buddies how that would affect that. It could be there just to save the frame but some how I doubt that.

Ok I talked to my friends that work in body shops. If you sleave and reenforce the crumple zone on the frame you could cause the air bag to go off in a accident it normaly would not go off in. This in turn could injure you. SO do not reenforce that part of the frame.

Possibly, yes, but the airbags work on inertia and there is a sensor up front, behind the grill, but most of it is controled by the computer under the arm rest. If the frame horns are reinforce, it may make some difference, but not so much that it would concern me.

We went through that scenario on the jeeps and their reinforced bumpers...

The decelleration rate is what sets off the bags sensor's...and the sensors are not on bumper or horns...

Essentially...when I run into a 120 lb deer at 50 mph, if the truck doesn't slow down fast enough "Suddenly" for the sensors to assume I hit something that will make me slam my face into the dash hard enough to ~ die, they don't trigger the bags.

If I hit a wall, or the back of a mack truck, etc...and the truck is actually slowing down suddenly enough -Suddenly stopped-, BANG! the bags go off.

The crumple zone can slow the process a bit by allowing the truck to stop slightly more gradually, but we are talking about a few inches...and its not like the sleeve/reinforcement is likely to support the force = mass times acceleration.... involved with that type of collision.

On jeeps at least, it doesn't seem to make enough difference to matter...and my worst impacts in the X were deer, not mack trucks, and ~100 to <200 lbs between 25 and 55 mph...and the bumper didn't budge, the frame horns didn't crumple, the deer pretty much absorbed the impact and transformed the involved energy into venison puree, etc.

I need to improve my lighting....might avoid more deer that way...

:rolleyes:

If I hit something hard enough to matter, I'll report back if the bags went off...otherwise...

.... I'm with Dagger, It doesn't seem to be enough difference to matter.

i wanna see this puree.

Its nasty....you don't really want to.

This is why I ended up buying the TJM.

While most bumpers only connect to the horns:


The TJM has a piece of 3/8" plate which connects the brackts to the frame tiedowns:



It may not look like much in this picture, but it is a beefy piece.

In my opinion, this results in much less stress on the frame horns.

I think the differences that you see will come at low speed collisions. More than likely if you hit something at 50 your airbags are going to go off, but if you get into a minor fender bender they shouldn't.

Yes it is a shock/deceleration censor. I have had someone back into me REALLY HARD!!! If it was not for the bumper it would have been really bad. TY ARB BUMPER!!!!

I say armor the hell out of it, drive safe and let all the idiots pay the price!!!

The sensors/airbags will act fine if you get into a real accident.

To further clarify what the ramifications are, this picture shows the (3/8") frame tiedown plate used by the TJM:



.

This gives the bumper 10.5" of connection distance between bolts as opposed to about 6" in a horn-only connection. The following diagram show numbers for a simple analysis:

Would having a front skid plate on give the bumper anymore strength? Assuming it is connected to the bumper and somewhere else on the frame.

Good illustration Jeff.

The ARB has wings that come back for the same purpose....we end up cutting them off when we do the BL's as there's no way to retain them when raising the bumper.

I like TJM's bracket that wraps the rails though, Brent's was pretty sturdy looking for example. I'm not sure how it would be retained if lifted...but, like the ARB's, you can always go to a fab shop and have them reinforce after the lift.

Thorsen -

A front skid that connects the front bumper to the front cross member would tend to reinforce the set up relative to horn distortion, and if butted to the cross member and bumper, act as a brace relative to downward or backward motion as well.

If not butted, the shear forces would be absorbed by the bolts themselves, rather than braced by the structural elements, and would not be as strong in that direction, albeit stronger overall than w/o the skid.

im planning on buy a 2" BL, which bumper do you guys recommend me to get after noticing these problems? thanks!

They are all good. I have both the Shrock and the ARB. The Shrock is a much better built bumper, IMHO. Whatever you get, make shure you torque the bolts correctly and check them periodically. Adding a few bolts to the Shrock doesn't hurt, but I have never had a problem and have yanked the hell out of my Shrock bumper. I think the problem is a few isolated issues.

Yeah - Dagger's right, they are all stong enough to pull with, even the ARB.

The extremes of force Jeff is illustrating involve what happens if you put a heavy load ON TOP of the bumper, pushing it straight down.

This is relevent, as some pulls involve the nose of the recovery X being higher than the recovered rig, so the X's nose gets pushed down by the pull....not straight down with the full load as shown, maybe a matter of 45º though, which perhaps ~ halves those numbers....and, if the bumper is lifted, increasing those numbers proportionally, as the height obove the frame rails does increase the forces as leverage increases, etc.

W/o doing the math, raising the bumper 2" would have less affect than going from 45º - 90º pull angle (If 90º is straight down, and 180º was straight ahead, etc.)...but it would be a measurable difference.

So - as far as I can tell, ALL of the bumpers mentioned can pull at their rated loads...some have higher/lower ratings though.

The difference in abilities seem related more to other factors, like front or side impact resistance, approach angle, quality of finish, weld through vs weld on construction, aesthetics, preferences for hidden vs exposed winch mounts, welds vs bolts, etc.

Deer for example are a severe test of any bumper...as the bumpers are braced against a winch's pull rather than a deer's push, etc.



The X's frame horns are not rock's of Gibraltar, and when I lifted my bumper, I welded a brace between the horns to compensate for the leverage extra forces from the raised winch point relative to the frame horns.

Its held steady, with no sign of torqueing, but I noticed that my exposed horn ends are taking a beating in rock gardens...so I plan on getting around to boxing in the end of the exposed horns with a decent piece of angle iron I found.



I never got around to installing a plate from the bumper back to the leading front plate, and frankly, there's not a whole lot of vulnerable stuff between them given the horns and brace to shield them....but I might do one to the new angle iron back if I ever have enough free time again....

:rolleyes:

Actually, these forces are calculated for straight ahead, as in the case of winching or pulling from recovery points on the front of the bumper. And these are very conservative estimates because I included the taps in the front of the horns in the 6", which are nonstructural connections. Realistically, those points will withstan very little, putting the stress on the remaining two bolts.

These numbers are rough, but do reflect the ratios of the two different designs.

EDIT:

You have dismissed these plates as being something that will simply be "cut off" in the event of a body lift. A body lift serves no purpose on my truck, as I plan on clearing 35s without one (like Rondo). So these plates will serve their purpose until I get a different bumper.



Where do you see trimming in this pic?

Ron's rig is proof that you can put 35's on a Fronty or Xterra with little or no trimming. I've seen him totally flex out that suspension with no rubbing.

Jeff - yeah, the only purpose of the BL is to clear larger tires, and if you can do it with a Sazall, etc...there's no point in the BL.

I wonder what he did then, every one else has rubbing...

Little or no trimming...?

Maybe removal of all well plastic ...or stop extensions?

Seriously, are there pics close up of the detail....it sounds like a real break through in wheel well clearance....

And, I LOVE clearance.

I'll be ALL over THAT mod this week if I knew what he did.



PS - I didn't diss your plates...I discussed ARB and TJM tie downs and the BL solutions, including just having something fabbed up...

How'd I know you could fit 35's w/o it?

He SASed with over 6" of lift.

EDIT:
The picture clearly shows that his plastic trim is intact.

OH - OK.

So he keeps the stuffed up side tire from coming up too high when the down side is drooping by doing what?



This is SAS stuff that's different from "just comes with front live axle stuff"...on my jeep situations, I needed to BL to make room for the upside stuffed tire to swing into when the opposite side was fully drooped, like what you'd get on an RTI ramp/big rock, etc.

This SAS stuff will be new for me.



How's it work?

Not to point out the obvious, but a bumper is supported by 4 bolts not 2, so your forces should be halved.

whats the difference between all the bumpers?
I really like the ARB bumper, but it seems that the shrockworks one is alot stronger in general. If i were to get the shrockworks bumper, what is it exactly you guys recommend me doing. You were saying something about adding a bolt?

Good point. The forces listed on the diagram are supported by 2 bolts each. The ratios of forces on the two configurations remain the same.

There are plenty of differences between the bumpers.

Calmini and Shrockworks both have thicker metal than ARB and TJM.

There are differences with bracketry, the tubing up top is different with all 3.

There are pictures of all 4 here:
XOC Thread

I think that all of these bumpers are very useful. They are all well-designed and tough. Calmini is still my favorite for the open winch mount. Years of recoveries in the Army have taught me that it's nice to be able to get to the winch to troubleshoot if necessary.

I know people running all of these bumpers. Most people seem satisfied with theirs. No bumper in the lot is perfect.

In answer to the bolt question...

Yes, The shock has an optional hole located further along the frame horn...and you just slide a bolt through it to get an extra mount point. The frame itself doesn't have another hole anywhere though, so you just use the bumper mount holes as a guide, and drill through the frame, and THEN slide the bolt through.

I like to use Grade 8 hardware for all of that....and locktite for the threads....but I didn't, because it was getting dark, and I wanted to play with the winch, as I had other X's over, etc.



Mine's been fine w/o it. I did torque the bolts, and they've never slipped, despite my, um, unique style in the rocks.

Another thing about proper tourque...When the bolts are tightened properly, the friction between the bumper & frame horns will take a lot of the forces. To loose and the shear resistance of the bolts have to take all the load. To tight and you can fail the bolt by having stressed the bolt paste its yeild strength. By doing this the bolt will strain and "loosen". When you retourque the bolt, you strain it even further. Eventually it will snap.

So if you continually find yourself retourquing these, it may be time to replace the hardware.

Good point Eric.



That's why I torque with a torque wrench...not too tight. not too loose....just right.

aaaahhhhh

I checked mine a few times...and for two years now, still tight, and no slippage.



I'll probably screw that up...I got some nice plate for some more armor I'm doing for the new OBA set-up...and plan to do some extra frame braces with it if I can keep it looking stock under there for the NJ inspection Nazi's...

did you guys ever hear of someone getting a Shrockworks bumper but welding the ARB tubing on top. I really like the tubing on the ARB but like the Shrockwork bumper because i find it to be the best all around.

Also, does anyone have the Calmini bumper? How come it doesnt come the D-ring hooks in the front?

Lots of people have the Calmini Bumper. It seems to be bulletproof. It is HEAVY, tho. Like I've said in the past, it's my favorite for the open winch mount.

Kevin has the ARB. He has hit deer, pedestrians, buildings, buffalo and other vehicles. So far it is holding up ok.

Is it good to pull another truck from the D-ring attachment on the ARB/Shrockwork bumper? From the previous post, people were saying that it might bend the bumper.
Does anyone have pics of how the ARB bumper is bolted on the X? Thanks!

I would always try to pull from the frame... it is the strongest spot and it is what you really want to attach to.

For just pulling/winching it should not be a problem at all but snatching NOPE!! Get that strap on the frame. When snatching you are putting some extreme loads on any point you attach to far more than if you had just winched. And it all happens so fast.

Oh and Jeff I never hit a building..... it was the side of a mountain!!!!! So there!!!

Just one last question concerning the Calmini bumper, do you guys know how much it weighs? thanks for all the info been very helpfull!

I belive it weighs about 115#. With skid plate and crating, shipping weight is 250# (they always overestimate, to be safe).

I have no idea what it will cost to ship to Canada, but the Calmini is generally the most expensive to ship.