On the highway on my way home from an all day wheelin’ marathon my auto transmission all of sudden lost Overdrive (depressing OD button light would go on/off but nothing would happen) and the RPM’s shoot up real high like 4th gear was missing or something while I was maintaining freeway speed. I pulled off at the next exit to check things out and didn’t see any thing abnormal…linkage, leaks, fluid level, smell, or anything I noticed. Kind of late and I wasn’t that far from home so I continued on and made it home.

Next day I check it out and everything visually looks ok but now I have no reverse gear so I go back inside and review the ESM and run through a bunch of diagnosis procedures, checks, and even attach the scanner and pretty much come up empty as far as codes. Some indication point to the tranny maybe in a partial “fail safe mode” according to the ESM but that doesn’t explain the reverse gear not working or the fact I was able to maintain highway speeds the night before even at a higher RPM range.

So I tow strap the X out of my driveway onto the street with my LC and then drive it to my local transmission shop. The tech who I know pretty well checks it out for about a hour and then tells me its time for a rebuild ($700-800 parts + $600-700 labor installed) or to start looking around for a remanufactured/rebuild one which will liked be cheaper.

After a few days I find a low mileage (90) day warranted auto tranny (60k) from a recommended local importer for less than half ($500) of what a rebuild costs or a fraction of a new factory one. Figure I can do the swap myself in the driveway over a weekend.

Started out Saturday about 10am and had the whole assembly dropped by dark the same day, with breaks for lunch, playing with the kids and what not but it was a PITA and really cramped with the X on jackstands and me on my back. The bolts on the bellhousing where tuff to get out and I had to use some really long extension. Really tight in places with my big hands and you have to remove all the wiring, exhaust piping, starter, etc not to mention the suspension components, driveshaft, et although having a SAS helped in that regards. Overall took me longer that I anticipated; I was beat andsore by the end of the day so I put off the reinstall until the following weekend. Not to mention I needed to replace the rear main seal which I found out was leaking previously.

The 2nd weekend the install went a little quicker and smoother with a friend who helped out more; we had the transmission and tranny all back together in an afternoon. Filled the fluids, double checked everything and went for a spin. Hum…well reverse works so does OD and the other gears but the ATP light comes on when in P and the 4x4 one doesn’t at all…back to the ESM.

The 3rd weekend day I decided to swap my ATP and 4x4 sensors from my old transfer case to the newly installed one and install the B&M transmission cooler. Go for the test drive and now the ATP light doesn’t come on and the 4x4 indicator does so I thinking I’m all set now. Hit the highway and then the check engine light comes on and the RPM are higher than they should so I head back home thinking what now? Hook up the scanner and get a P720 code…Vehicle speed sensor error.

4th weekend day I rest the code and decided to swap the VSS from my old tcase to the new one since I know that one works and I even benched checked to make sure via the ESM procedure. After the swap the code still reappears, shifts are still off so back to the ESM for me. The only thing it might be is the revolution sensor which I find out is a magnet sensor that gets speed info from the tailshaft that is send to the TCM for shifts and ECM for diags. Trouble is it’s on top of the tranny and ESM says the tranny must be drooped to access. Damn, I’m thinking I’m cursed now so I go drown my sorrows and ponder what to do next.

5th weekend day I ask a neighbor with really small hands if he could access the wiring loom attached to the revolution sensor, after about 15 minutes of smoke and mirrors he manages to get a hold of it. We tape the old loom to it and pull it out though the engine bay and then he connects the old loom to the sensor. Take it for a test drive and yippe everything finally works right. On further inspect I noticed one of the wires on the loom attached to new transmission for the revolution sensor was partly damaged once we pulled it.

So what’s the moral of the story? Don’t assume sensors works even if they look newer than what you have, swap in the ones you know are good. The ESM and small hands are invaluable.

Man it was sweet to wheel and drive again after that. No more weekend's wrenching for me the rest of the year I hope.

Background: ~ 140k; I’m the 2nd owner from 120K on. PO told me regular services & fluid changes always done at recommend intervals or before and from the records, conditions of the vehicle that seems accurate to me. I changed the tcase and tranny fluid about 15k ago. Prior to the day detailed above no problems detected or noted.

Ugh....you're making me wish my Xterra had a manual like my Frontier does....

As far as long term reliability of these autos I have my doubts now, seeing how my 90’ pathy also had problems… needed a partial rebuild at ~125k…torque converter, reverse band, seals, etc. The parts came out to ~ $600 for that one so that’s one of the reasons I decided not to rebuild this time.

The 1st gen xterra auto transmissions are basically the same ones used on the pathys from 90-99 and my transmission shop said they’ve seen a fair number of those. Not to mention the recent posts from others in this forum about their autos.

Compared to the auto transmission I’ve had in my Toyota trucks (>200k on 2 of them) I don’t think the Nissan ones are nearly as good or last as long.

But maybe it’s just my luck? I do wheel a lot and harder then most so that may have something to do with it? I would like to her from Cyclemut or some of the Nissan techs about their experiences & opinions of the autos longer term longevity ?

BTW did I mention swapping on jackstands is a real PITA, would be much easier on a lift.

If/when it goes out just swap in a manual like System-f did

it can't be too bad, i did a T-converter swap by myself in a 1 car garage on jackstands right after i swapped a 9in rear in.

We see a ton more issues with the manual trannies than we do with the autos. First gear stripping in the mannies is the big one. Clutches being the second one.

The autos in the Pathfinders usually have one issue, and that is the secondary input shaft stripping where it engages the torque convertor, sending metal and debris throughout the trans, causing catastrophic failure.

We haven't seen anything like that with the newer autos, as I believe they've strengthened the hardness of the failing shaft. That, and the electronics of the auto itself can help the transmission out (upping line pressure when excessive slippage is occuring throught the line pressure solenoid) when needed.

I just checked ASIST, and there is Nissan tip on the issue for Xtoolbox's Blackhawk.

Double check the banjo bolts for the transmission cooler lines! Make sure they've been drilled. According to the tip, some bolts made it through the machining process, without being drilled! This would cause the fluid to never go through the cooler, and cause the transmission to run hot.

Now, I would've thought that the transmission would've shelled long before this, if this was the case, especially what with what we put them through. So I doubt Xtoolbox will find a problem there, but just to be sure...you know?

I think the autos are fine. I'll always have an auto, even if my unit does fail, I won't be putting in a manual, no way!