transmission problem?

Okay, I need some help/advice/suggestions. I finally got my jeep up and running after several years in the garage. Unfortunately I am now having trouble shifting gears. It is hard to get the jeep into and out of gear and downshifting is not possible at all.
My initial thought was the clutch. But I can't see anything wrong. I can watch through the inspection plate and see that the clutch is completely disengaging the transmission when pushed.
If I shift the T-case in Neutral and run through the gears everything seems to work fine shifting up and down. Does this mean I can rule out the transmission and consider the issue in the t-case? The synchros look okay in the transmission. Fluid level is correct in both.

Any ideas on fixing or diagnosing the problem would be greatly appreciated.

Thanks in advance.

 

have you driven the Jeep?
the clutch disc could be stuck/frozen to the flywheel from sitting.
with the trans in gear and you depress the clutch; what happens when you start the engine ? does the Jeep move ?
if so, this would indicate clutch problem: adjustment, stuck disc, etc
the trans will grind if you try to put it directly into first gear without first shifting it up into second gear, then into first; by doing it this way, it allows the gears to slow down; first/reverse gears aren't sychronized.
the transfer case shouldn't have any effect on this at all
was the trans shifting fine before the long period of storage ?

 

I have driven the jeep. Just up and down the alley and around the block but I am able to go through all 3 gears. When driving I can upshift but it is not smooth and I feel like I am just forcing it in gear. I can't downshift at all.
When I try to start the jeep in gear with the clutch depressed it does not jump at all.
The transmission shifted fine before my teardown. I didn't do any work on the transmission, just replaced seals.

And since I didn't state it earlier, it is the stock drivetrain -- L134, T90, Dana 18.

 

hmm
sounds like we can rule out the clutch then
the trans shift forks fit into grooves on the first/reverse slider and the 2-3 synchro hub
are we sure the shift forks are in the grooves ?
short of replacing the synchros and checking for an end play problem in the trans mainshaft, that's all I can think of.
I suppose the forks could be bent and worn, but if it were shifting fine before, that doesn't seem likely.

 

I went out and checked the forks. They are in the correct grooves. There is some wear on the back of the forks but it doesn't looks too severe.
I looked at the synchros and I can't see any obvious severe wear on any of them.
How would I check or adjust an endplay problem? I did have the transmission and transfer case apart. Could I have messed something up when I reconnected them that might cause it? What about the nut on the back of the transmission output shaft, anything possible there, too tight?

 

the nut needs to be good and tight
usually excessive endplay is associated with popping out of gear
did you take the trans apart ?

 

Nope, transmission did not get taken apart. I disconnected it from the t-case but I did not disassemble it.

 

well
the only other thing I can think of would be...
when you seperated the trans from the transfer case, were you carefull to not let the trans mainshaft move back and possibly drop the mainshaft rollers inside the main drive gear ?
if one or two fell out (don't know if that's possible) now the shaft wouldn't be in proper alignment with the mainshaft....
or
the pilot bushing....was it there and in good shape?
if the main drive is out of alignment with the mainshaft ?

did you remove the front bearing retainer ?

I'm running out of ideas.......

shift tower problem(s) ?

 

If the "mainshaft rollers" are the bearings on the front of the transmission then yes I was careful to insure those were there properly. Many years ago I spent a good day looking for one of those things. Finally found it in the transfer case so I learned then to be careful with those.
I replaced the pilot bushing when I put it back together.
The front bearing retainer I removed and actually replaced. I put it all back together and had a leak from the front of the transmission. When I went to buy a new seal the place I was buying it from said they had a replacement bearing retainer with an integrated seal. I went that route instead of a replacement felt seal.
If the problem was endplay would it be present with or without a load on the transmission? The fact that I could put the t-case in neutral and go through all the gears smoothly seems like it should mean something but maybe it doesn't. I haven't tried removing the driveshaft to see if the problem exists without the load but still through the t-case. Maybe I'll try that tomorrow.

 

I agree
I don't see the connection with that...

 

so when you try to shift it, the gears grind, or there just seems to be a lot of force on the shifter required to make it shift. someone else here will know if this is possible, but it has not happened to me yet. If it isn't grinding, just hard to shift, If I remember right, the rods that the forks are on, slide out the back of a T-90 and into the front of the T/C when it is shifted. the T/C indexes to the back of the trans via the bearing, and maybe a dowel pin, but I cant remember for sure. could the T/C be misaligned with the trans, causing the rods to drag against the T/C housing? missing dowel pin? wrong bearing? big hole T/C stuck on over small bearing? I'll be interested to see how this comes out, I am getting ready to pull all that out of mine, reseal the engine, and go through the trans, and T/C. havn't had any trouble other than a few oil leaks, but mine has never been apart, so it could be on borrowed time.

 

OK I read back through your posts, doesn't seem likely they would drag only when the T/C is in neutral, and I sure can't think of any scenario where the T/C could cause a shifting problem in the trans. It feel like the problem might be a mainshaft endplay issue. could it be that there is too much preload on it, like its too tight and the synchros are having a hard time getting the speeds to match up between shifts, because everything is jammed together so tight it all wants to go the same speed. Not completely sure this is possible either, just my 2 cents.

 

I tried disconnecting the rear driveshaft and running through the gears. It seems like if there isn't a load on the transmission it does okay. When I actually drive it I get the issue.
If there was an issue with the preload on the mainshaft bearing would it shift okay without a load on the transmission?
If I put everything in nuetral and remove the shifter how difficult should it be to manually turn the shaft? Would that actually tell me anything?

 

first let me say, I am no expert on this stuff, but a long time hobbyist. I have worked on and overhauled every component in an old jeep at one time or another at least twice. So I am giving you my opinion. I know there are guys on this forum with much more experience than me, so If I am off track or wrong about anything I say, correct me, or add your opinions, my feelings won't be hurt.
OK, when you step on the clutch to shift, there is no load on the trans. So I feel like it is not so much the load on the transmission that is affecting the shifting, but the fact that the output shaft of the trans is being turned by the rear wheels once you step or the clutch. I would think if the cover was off the trans with everything in neutral, you should be able to tell if there is excessive endplay in the mainshaft. I would try it with clutched engaged and disengaged. If it is tight enough to effect the shifting, you might be able to determine that too. I would think with everything in neutral the output shaft should turn fairly easily, without alot of drag,if you step on the clutch and turn the output shaft by hand, It should not be bound against the input shaft hard enough to make it turn, so it other words, there should be no change in the amount of drag on the output shaft when you step on clutch. I think since you did change the bearing retainer, it is possible that this is your problem. The shafts could be jammed together hard enough so that when you are driving down the road, step on the clutch and try to shift, once it hits neutral, the input shaft tries to match the speed of the output, and the synchros are not able to do their job, which is syncronize the speeds of the shafts, so the gears will mesh. With that said, I would think it would shift into high gear without much trouble if this was the problem, since they would need to be going the same speed anyway. Are you any good at running it through the gears without using the clutch, you should be able to do that. didn't intend to write a book on it, just couldn't find a shorter way to express my thoughts. Hope they make sense.