Bigger Hammer
Dec 30, 2010
Northern California. Shasta and Trinity Counties
Willys Model
Willys Year:
I posted this in the Weekend Update but it's obvious to me, now, that this would have been a better place, sorry.

The tranny in my 6 cylinder willys won't stay in 2nd unless it's under a load. I have a four cylinder jeep engine on the floor in my shop with an atached T-90 that appears to be in good shape. I figured a T-90 is a T-90 so I'd just swap them.
Then I was told that the input shaft and bearing retainer would have to be pulled off of the tranny in my truck and put onto the tranny from off of the 4 cylinder. I was told it wasn't a big deal, unbolt the retainer, the shaft slips out and stick them on the better tranny. I stopped at the local 4WD store today to see if I needed some sort of seal or packing when I made the swap and I was told that you don't just "remove the retainer and slip out the input shaft".
I was told that the gear on the end of the shaft hangs up on a gear in the bottom of the transmission. I was told that I'd need to take apart some of the tranny to get the shaft out. If that's true and this is going to turn into a major event then I'm thinking that perhaps I should rebuild the tranny that's in there. I was just trying to make this easy.
I was also going to have to remove the yokes from the 4cyl transfercase and replace with the yokes from 6cyl transfer case as they are a different style and I want to keep what I've been using. If I don't swap trannies then this becomes a non issue.
I've never rebuilt a tranny but I have a friend, retired county road dept mechanic, that says it's a piece of cake.
OK fellows, this is what you're here for....to give people like me advice.
Thanks in Advance, JIM
This is a usual problem with a worn out T-90. What you need to do is replace the synchronizer (2-3 synchronizer is the only synchro in a T-90). I rebuilt my T-90 and replaced my synchronizer assembly just in case, and it was rather trivial. I had never even taken a transmission apart before but I had it done in no time. These things are pretty simple, and I'm sure there are some writeups online about rebuilding the T-90. You don't need any puller tools or anything that I can remember. You may want to replace the roller bearings while you have it out as well.
Jim, here's some points by the numbers:
1. Good advice on the gears / syncros, but it's been my experience that it has been a shifter fork issue. Twice before I had the same problem. On both I replaced the shifter fork and everything was great. You can't tell if it's the fork by looking at it, but they just wear down after years of use and then 2nd gear doesn't get completely meshed. Let off the gas and it pops out.

2. After you take the tower off of the trans, you'll see an oil slinger bolted to the front (if nobody before you lost it). This has to be removed. Then you can pop the snap ring and pull the input shaft. It will seem to hang up a bit, but it will slide out.

Good luck and have fun with it.
Go to Rick Grovers website www.asu.edu and he has a link to Rick Stivers website (dont remember his site #) and he has a great writeup on rebuilding the T-90 its not that hard a friend and myself rebuild mine and I know nothin about transmissions it was no biggie. good luck
go to vernco.com the above link doesn't take you there but verns site does just go to links and both of those guys sites are listed sorry about that and again best of luck :D
Order a rebuild kit and tear into it. The T-90 is about as simple as transmissions get and the only things to watch for is the oil slinger on the input shaft and the needle bearings they use in several places. If your tranny is showing some wear you may want to look into the transfer case at some point also. The intermediate shaft in the transfer case will likely have some damage as they seem to not oil properly.
Fellows, I can't thank you all enough for the encouragement and for the suggestions. Especially thanks for the link to the article re: rebuilding the T-90. I got so absorbed reading it this morning that I didn't realize it had gotten light outside until I heard the cows bawling for their breakfast. The chickens were not just a little annoyed, either, when they were let out and fed late. :oops:
I'm thinking that I will do as you suggest and pull the tranny and take a stab at going through it myself.

One other little thing that's troubling me a little on another subject. I have a two barrel carb on Leona. The choke works off of the exhaust manifold (not sure what the technical term for this is). Anyway I have a mechanical fuel pump and and inline electric fuel pump between the fuel tank and the mechanical pump. There are no return lines or pressure regulators in this system. I was reading something here that lead me to believe that maybe this is a poor arrangement :?:
Let the comments begin.
Jim, I'm sure you will get lots of different points coming to you on these. Everyone has their preference when it comes to fuel pumps. These are good guys and everyone seems to know what they're talking about, but have different ideas, so you will have to take it all in and then decide for yourself. Here is my two cents on your inquiries.

Carburetor - Make sure the idle step up is adjusted correctly for the choke to work properly, or you will just get really pissed off at it. I don't have the numbers off the top of my head, but you should be somewhere around 1250 rpm when the choke is on. Of course that's assuming that the choke spring and butterfly are working right as well. When all is right, it works well.

Fuel pump - My personal opinion is that the electric just doesn't belong. It sounds like it was installed by the PO, so you really don't know what the pressure rating is on it. If it's too much, you will probably ruin the diaphram in your mechanical pump and maybe have flooding issues. I sounds like you have a fairly stock set up, so why throw aftermarket stuff in the mix?

Just my thoughts.
Leona said:
... Anyway I have a mechanical fuel pump and and inline electric fuel pump between the fuel tank and the mechanical pump. ...

My '60 wagon was set up the same way, electric pump near the tank pushing through the mechanical pump. The electric pump was wired to the key, so it was on no matter what. I found that it would flood the engine if I left the key on for a few minutes without the engine running, while trying to sort out some other electrical issues. I also noticed that the muffler is bulged out like it had a small explosion inside... I'm assuming at some point in the past it filled with gas and was lit off.

I wired the electric pump to a switch so I could have the key on without pumping gas, and discovered that the mechanical pump I have works fine. Now I only use the electric pump if the wagon has been sitting for a long while, to prime the carb for an easier start-up.