Transmission jumps out of second gear

The transmission likes to jump out of second gear when I'm on hills. I'm told this is a common problem with flat fenders. Is this an easy fix or is my tranny about to go? Oh yeah, I should add that I'm talking about my stock T-90. Thanks.

 

syncros and worn bearings

 

yup, mine does it too... seems to happen most when i let off the gas a bit in second gear... I'm gonna live with it for now since im planning on swapping it out anyway.

 

I have the same promblem with my 75,we are planning on doing a swap.

 

Who's got the best deal on a rebuild kit?

 

e-bay has them listed for what seems to be a good price....can't answer how good a deal it would be though....

 

I've installed one of Herm's that was part of his 4 cyl T90 to V6 conversion. gud stuff 8)

You dont really even need a manual, its not as difficult as it sounds. punch out counter rotation set shaft <bottom shaft> to allow gearset to rest in bottom of the case. Main set comes right out to and takes minutes to replace worn items. Have a spare T-90 handy as you may have to combine shafts and gears of both to make one good tranny. Herm's kit should have needle bearings for the lower counter set -- I used vaseline to hold them in place for the re-install of that lower pin <shaft>

I need to build a spare T90 as a matter of fact

 

Used the cheap kit on my 45 MB T-84 trans jumps out of second gear also.To agree with others spend the extra money and get the GOOD kit.

 

So what would be in a "good" rebuild kit that the others wouldn't have?

 

Herm has a good rep : http://www.hermtheoverdriveguy.com/id3.htm

 

I've been having the same problem, (or 'had' the same problem) with my T90. I decided to go with the full kit from Herm which should help, but honestly, there are a few things not replaced in this kit that can be the real source of your problem. I think the most common is wear on the small synchro teeth (not the right name, but hope you know what I mean) on the 2nd gear itself and wear on the sliding collar that ties 2nd gear to the mainshaft when you are in 2nd gear. Herm's recommendation is if there is any wear whatsoever on the gear or the collar, to go ahead and replace the worn parts. It is a little pricey, ~100 for the whole mess, but should fix the problem for a long time.

The other thing I noticed on my tranny is that depending on the amount of wear on the shift fork, and where the tower is actually bolted down (note there is some slop between the tower and the case) you may or may not be fully 100% seating the collar into 2nd gear. Since the actual connection between the teeth and collar is only about 3/16", you might try shifting the shift tower back and/or replacing or building up your shift fork. If it's already jumping out of gear, the damage is done, but it might help prevent wear in the future. (If you move this stuff too far to the rear, you'll start having problems with 3rd gear and/or start wearing down the collar or fork because you're pushing against 2nd gear a little too hard , so I'd be careful with that one.)

And then the last thing you might do (band-aid IMO) are stiffer springs for the shift detent balls.

One last thing worth mentioning is that some of the new jeeps (rumor is CJ-3B) have a slightly lower gear ratio. You can swap the input gear and I'm blanking on the name, the lower counter rotating gear set, which will drop first from ~2.8:1 to about 3.38:1. 2nd also drops a similar percentage.

I did all of the above and the end result is that I've got more time and $$ tied up in my T90 than any sain person should, but what the heck, I also could have had a 300hp V8 and instead I've got a freshly rebuilt L134. To each their own. Or something like that