Hey gang,

So I took my two kayaks up to Michigan over the 4th. I use the kayak stackers with 4 mighty mounts holding the stacker bars to the roof rack.

I get to my destination and low and behold, one of the 4 mighty mounts had failed completely. The washer that is embedded in the mighty mount (which effectively clamps the mount around the crossbar) had popped completely out of it's housing. I looked at the other 3 mounts, and they had severe bulging in the plastic above the washer, indicating that they were ready to pop too.

Anyone else have this problem?? I had to leave one of my dear kayaks up in Michigan because no place up there had the 28H mounts.

Here's my next question: did this happen because I overtightened the mounts, or because I have a Perception Acadia and Perception Carolina (approx. 100 - 110 pounds total) strapped to them, and the mounts just can't handle that kind of weight.

I'm thinking if I just add another washer to the screw BELOW the mighty mount, it ought to keep the embedded washer from failing.

Your thoughts are greatly appreciated. I posted this here instead of the kayaking forum because I think the mighty mounts are used for much more than just kayaks.

Washers ?

I don't see any washers anywhere on horizontal mighty-mounts...

Did you follow these directions ?

I had similar issues with the mighty mounts, and I opt'd to get the x-bar system (I think that's what it's called), so that I have the 4 (sturdy) mount points and 2 bars and just ditch the mighty mounts. When I'm hauling a bunch of kayaks, I want to make sure everything's sturdy 'cause you're looking at like 300-400lbs if you have 3-4 boats up there. I haven't had a problem with my setup... but maybe I didn't put the mighty mounts on correctly either?

Plastic is plastic! it dries, cracks, warps and fatigues. i would go the x-tower route and if you are interested I might be selling mine. pm me if interested i even have an extra set of 48" crossbars.

I have had 6 mighty mounts on my roof for 4 years now holding a 60 lb Hi-Lift jack and a safari rack, which gets filled with heavy camping gear during the Summer, then subjected to off-road travel. No cracks or damage yet.
They are a very sturdy plastic.

I had them on my X with my safari basket before I replaced it with the loadwarrior. Yakima products are all made from the same plastic and I had one of the mounts on my wheel fork crack, luckily I noticed it before any damage was done. i personally would not trust plastic to hold up to that type of weight and stress. Just think of the force on those mighty mounts while offroading or carrying alot of weight. Besides the other mounts all have recommended weight capacities, does anybody know what it is for the mighty mounts.

You probably over tightened them.

FYI - I have my MM's set up with a washer, lock washer, then nut BELOW the MM. Go to a hardware store and buy some extra long bolts and you are good to go. Works perfect! They key though is to not overtighten and strain the plastic.

Even if you go the x-tower route, you are likely still using Yakima Mighty Mounts. (The standard ones, not the special Xterra ones)

Oh yeah, I followed those directions to a "T". I didn't want to fool around when dealing with two possible projectile missles strapped to the top of the vehicle.

When I say washers, I'm talking about the metal threaded nut (gold/brass colored) that is embedded in the plastic of the mighty mount.

As far as fatigue being a factor - I've only had the mounts for a year, so we're talking about probably a dozen or so uses. I take the mounts off when not hauling my kayaks.

Thanks for all the suggestions, keep them coming. I think I'll order another set, and go the extra mile of using longer bolts, with at least one additional washer at the bottom of the bolt. This will be in addition to not tightening them like crazy. And I'll keep a WICKED eye on the mounts.

I'll try to get some pics scanned of the broken mount so everyone knows exactly what I'm talking about here.

Perhaps taking them off and on over a period of time weakened the threads or something? I believe the mighty mounts are meant to stay on there for a good long time. I have had a set on my rack for ages without any sign of abnormal wear or breakage. Good luck.

I've been using my mmounts for the past 3 years (but for my bikes), take them on and off as the season changes, inspect them fully when reinstalling everything, no cracks, no problems. But I can see how you might pull the inset nut out by over tightening them (there is supposed to be a slight gap formed between the top and bottom half where the bolt goes through, created by the little tab on the top part) I should also mention I attach my trays with a longer bolt and nut at the very bottom.