Transmission????

[Skboyd]

Ok transmission guys here's the issue.
This just started, goes into gear and shifts gears going forward no problem. Put in reverse and there's a catch and it wants to jump makes noise wont move to good. So it's only reverse.
In neutral I can roll forward and backwards fine, no noise or drag. Blocked up I can spin tires either direction fine, in gear. So no brake stuck.
I did replace oil in transmission/ transfer this winter. First couple trips out this year no problem. Then one day it kinda grabbed then progressively got worse. So we are parked until fixed.
Now gotta find source of problem.
Cant wait to hear this good news... lol

Thanks
Scott

[TJones]

Did you take the shift tower off to fill the tranny and transfer case?
It sounds like the first and reverse shift fork missed the slider when it was put back together.
Maybe one of the Admin’s will chime in shortly and figure your dilemma out, it’s gotta be pretty simple.

[bmorgil]

If it goes into first without any trouble, it sounds like the teeth are busted on the reverse idler and/or the idler mating side of the 1st / reverse gear.

Before I assumed transmission damage however, be sure the shifter and linkage is moving all the way into gear. A broken poppet spring in the cover can stop it from shifting all the way into gear. The reverse shift requires the lever to move the shift fork and 1st / reverse gear on the mainshaft. It takes the most force to make the 1st / reverse shifts.

[Skboyd]

I did not remove shift tower. I used fill plug.
And before I dig into transmission, could it be something in the rear end? Just checking to narrow search?

[bmorgil]

Scott you have done a pretty good job of pinning it down. If it is fine in all gears except reverse, as long as it is shifting all the way into reverse, I think you have it figured out.

[Skboyd]

Well I guess I'll dive in. Thank you for the guidance. Wish me luck. Lol

[bmorgil]

You are an hour away Scott. If you need help, we will try and figure it out!

[Skboyd]

Sounds great, will definitely keep that in mind. May even get in touch when I start. Gonna do my homework first. Greatly appreciate that.

[gmwillys]

Bmorgil is the best in the business when it comes to drive lines. He knows his stuff, that's for sure.

[bmorgil]

gm is way too kind. I am heading for the oldest in the business however!

Scott, this could be something you might be able to see before you pull the transmission. Drain the lube and pull the floorboard and the cover off the trans. If gears are broken, I would expect to see metal and small pieces in the lube that drains out. With the cover off, position the transmission shift collar in neutral if it isn't already. You should be able to slide the first/reverse gear to the rear and engage the gear into the reverse idler. Get someone to help, and with the rear wheels off the ground and the clutch disengaged, you should be able to spin the driveshaft and watch inside the transmission as it spins. Look down into the case and see if everything is turning smoothly. If there are busted gears you should be able to see or hear it.

[TJones]

Doctor Dana!!!

[Skboyd]

Lol, I knew the doctor could help me.
That answered my the question in my head, if I could inspect from top cover. Thanks that helps for sure. You mentioned the poppet spring? Looking at the manual my understanding is the spring is in top cover and can be inspected after removing top cover.? Is that correct?

[bmorgil]

Yes, they are in the cover. https://www.kaiserwillys.com/diagram/cj-3a-diagrams/transmission-diagrams-willys-cj-3a/t-90-transmission-top-shifter/transmission-top-shifter Item 4. I am beginning to think I will never take a T90 cover apart and NOT find a broken spring.

Take two springs and call me in the morning.

[Skboyd]

Lol. Thanks doc! Hope my top feels better.
With working to many hours thru the week, I plan to start the procedure this weekend. Will report back. Or ask more questions.
Thank you once again.

[Skboyd]

I meant my T 90.. good night

[Skboyd]

Update...
Drained oil, few small metal pieces. Also some metal flakes inside case, nothing big. Did as you describe wheels up and turn drive shaft. Did not hear anything or notice a broken gear or tooth. Now the reverse gear did have a couple sharp edges on teeth. Not all to rear side of gear.... like maybe it's not pushing all the way back maybe?... have not disassembled top part to inspect poppet spring yet.wanted to check in before doing so. My guess would be metal flakes from reverse gear not in correct position...

[bmorgil]

Scott can you take a picture up close of the gears?

[Skboyd]

Pics of transmission gears.

[TJones]

Looks like the input shaft may be missing a tooth down towards the drivers side bottom or just a piece of one.

[bmorgil]

I do see that tooth TJ. I also don't see anything that would prevent reverse. The transmission has been shifted once or twice no question about it! Lots of wear on the clutching teeth. If that is a piece missing from the input gear, something must have went through the teeth.

Scott, how do the teeth look? Does the input gear have broken teeth? Rotate the transmission gears and check all the teeth. The reverse idler needs a good look. Look at each tooth. If there are teeth missing on a gear that would be the issue. Does the cover shift properly on the bench?

[Skboyd]

The cover shifts hard with force leading me to believe the spring is ok. One would think. Just now messing around some more and found a corner tooth wore on reverse idle gear. Help me with my gear coordinates, the main input is the one to the very front on transmission?? Correct? I'm going back out to spin some more.

I got a little distracted yesterday with the arrival of my first grandson.
Thanks guys! I'm still investigating will return shortly.

[bmorgil]

Correct Scott, the input gear or "Input Shaft" is the gear closest to the engine. In the rear of the trans the large gear with straight teeth is the First and Reverse Gear. This link will help. Click on the number balloon next to the gear, and it will take you to the name and the part number.

https://somarmotor.com/diagram68.html

Those are good pictures. Give us more of the same. Lets see a few pictures of suspected broken teeth as you inspect the gears.

Congratulations on the new Grandson Grandpa!

[Skboyd]

Yes all gears look shifted... lol but not broken. The reverse slide gear has teeth rounded we will say. The reverse idler appears to have two teeth wore or chipped on corners.... here's some pics.

[LarrBeard]

Yes - excellent pictures. Those make it a lot easier to troubleshoot things.

[bmorgil]

I don't see anything that indicates the trans has damage severe enough to stop it from moving in reverse. I cannot see the counter shaft gear however. The damage to the teeth in the reverse area is from that familiar "grinding" sound when someone shifts it incorrectly or, it spits it out of gear because it isn't fully engaged. I am wondering if it was all the way in reverse. There isn't much to go wrong here. It doesn't appear to have any internal damage that would keep it from moving in reverse.

If you shifted it into reverse and it didn't move or, moved intermittently, I would have to say it is not going into gear. Can you slide the first/reverse gear reward and engage it fully into the reverse idler? If you can engage the gears, when you rotate the driveshaft does it turn the first/reverse sliding gear? If it does keep looking for a spot that is missing teeth. Make sure you check the teeth on the counter shaft where the counter shaft gear meshes with the reverse idler. Missing teeth there would also cause no or intermittent reverse. There isn't much here to go wrong. If everything is fine in the forward gears, you have removed the rest of the drive line from suspicion. It either isn't going into reverse or there are teeth missing.

[Skboyd]

Now my head hurts...
I am confident no missing or broken teeth.
I can slide gear all way back, a little wiggle to help but goes right back. Clutch is depressed to floor, spin the tire and gears start turning but then kinda stop, stop wheel and gears kinda kick opposite direction. Would guess backlash from rear end? Things seem to be moving together....I see gears moving I think all good. This is where my lack of knowledge may miss something maybe. Now I put top cover back in vise and shifted to double check spring, have not disassembled top cover at this point.. it shifts hard with force, but notice it kinda backs off maybe an 1/8 inch to 3/16 eyeballing. So not sure if that's normal or a broke poppet spring.?
Now when I first jacked up before removing covers.. I was spinning driveshaft with nothing noticeable, I even started motor and put in reverse let clutch out and wheels seemed to spin no noise or drag... dont fail me jack stands. Lol. So when wheels on ground and put in reverse it jumps not wanting to go. Am I getting off track thinking possible rear end? It seems obvious not going into reverse all the way but why? Maybe back to poppet spring? Overthinking here? Maybe need to go fishing for a bit.
My first time in a transmission but I'm not seeing the obvious, or maybe I am......

[LarrBeard]

"Am I getting off track thinking possible rear end?"

I've just been watching and keeping quiet because I am by no means a transmission/differential guy - I'm a sparktrician - so take the following comments with a tablespoon of salt.

My experience is with Timken differentials, so they don't have a lot in common with Dana's. A long time ago, I had a bearing failure on the tail shaft of the pinion gear. After all of the awful noises cleared and the pieces fell out of the teeth of the pinion and ring gears, the truck would only move in one direction (I can't recall which) because the unsupported pinion would drive out of the ring gear in one direction and back into the ring gear teeth in the other. It was very noisy, but it did move enough to let me get into the garage where I swapped the rear end for another Timken.

BMorgil - is anything like that a possibility with Dana units?

[bmorgil]

The Dana doesn't use the Pinion support bearing. I would expect Larry there was noise when you lost that bearing. The thing that is making this a difficult diagnoses is the fact that it moves under power with no issues and no noise. The only time it wont move is in reverse. That narrows it down a lot. It has to be in the reverse gear power flow.

The comment "spin the tire and gears start turning but then kinda stop, stop wheel and gears kinda kick opposite direction" I need to understand. Are you saying the driveshaft is turning and the wheels are turning and suddenly the driveshaft stops and the wheels turn opposite directions? It is important you are rotating the output shaft of the transmission. You want to make sure the driveshaft is turning and so are the gears. The driveshaft is hooked directly to the main shaft in the transmission.

Lets clarify wont move in reverse. Does it bog down and stall or just sit there and rev?

[LarrBeard]

"I would expect Larry there was noise when you lost that bearing."

Oh yeah - and my chin bounced off the steering wheel when the back wheels locked up...

[Skboyd]

Well I'm by myself, so my foot is spinning tire while I'm stretching out looking at gears. Now I did turn drive shaft by hand underneath while my lady looked at gears... we will leave it there. Lol

I'll back up to to first time it happened. Put in reverse let out clutch it seemed to catch made noise and jerked a little. Caught my attention, never did that b4. The next time out .... I let clutch out and it seemed to not wanna start moving then did, was rough with more noise. Last time out same story but more noise and kinda jumped jerked while trying to roll back in garage.... seems like clutch gotta come out farther to get moving and more fuel to get going compared to foreward gears. The last time was way worse than first. And does not do all time... say come to stop shift in reverse rough start, push in clutch while moving and let clutch back out that time may be smooth.

I need to get a buddy to turn drive shaft I believe.. I was spinning gears inside case by hand mostly checking for broken teeth...

[Skboyd]

She did say the thing was turning but then the reverse gear moved forward off idler and it stopped... while I was turning drive shaft. I need to see for myself.

[bmorgil]

When driving around in the forward gears there were no problems? The fact that this is only happening in reverse is definitely narrowing it down to the reverse gears. Take a few pics of the cover. Does the reverse/first shift fork look bent? Are the pads worn off the shift fork where it touches the sliding gear?

This is a picture of bad wear.

9545

[Skboyd]

No problems at all in all 3 foreward gears.
Earlier I stated the shift lever goes all the way but will kick back a little, 1/8 inch maybe. Question the spring? Maybe I should take apart?
I will get pics of forks. Yes! Only reverse is the issue so I say it narrows it down.

[Skboyd]

Shift fork pics

[Skboyd]

More shift fork pics

[Skboyd]

And some more pics

[Skboyd]

Nothing appears to be bent. I would not say bad wear just a good polish, I think the last pic shows the most wear .

[bmorgil]

Scott, with what you are describing and what we see in the pictures, I cant spot anything mechanically preventing reverse. The only thing left is the cover. The transmission looks OK to transfer power from what I can see. It must not be going into gear.

[Skboyd]

What I did this morning...
Put cover on put in neutral with shift lever. Remove cover mark gear location. Put cover back on shift into reverse, remove cover and marked location. Had a helper hand today, turned drive shaft all gears turning in transmission.
Included pics of gear location. Pic with N only is neutral location.... rest of pics show gear location after shifting and removing cover before turning drive shaft. I agree acts like doesn't want to go in or stay in gear in reverse only. So I sent pics to ask if gear location looks proper.

[bmorgil]

Put it back together Scott, I cant see a thing wrong that would keep it from moving in reverse. There must be a body under the car. I am going to say something strange is happening like the engine is moving and releasing and applying the clutch. On that thought are the motor mounts in good shape?

[Skboyd]

Body under the car! That would be an easy fix!
Good news transmission ok. Yes all mounts look good, bolts tight. I'll keep looking.... I just remember first time happened, shifted in gear clutch out and clunk and jump. Was hard enough to be suspicious, so something out of sorts. Somewhere. I'll keep looking... thank you so much for all your time and knowledge. I feel a little smarter now in another area of the jeep. Grandma did name it Bad News, she knew something I bet.

[Skboyd]

Paging Dr.Dana, paging Dr. Dana... or anyone who has experienced this.

Update.
So I did find a broken poppet spring, but on the high gear side. All replaced and transmission back together... as I expected same problem exist. My dad came down today to help.
Put on jack stands, put in reverse and it's like the drive shaft and axle bind up and shake, noise also. Did go thru forward gears and 3rd gear also did a little bit. Removed diff cover, metal dust in oil not chunks. Examined gears nothing broken. Turn drive shaft by hand now at this point, he thought it was a little sloppy back and forth. We could see nothing that said oh that's it. Now turn drive shaft counter clockwise and turns smoothly. But when turn drive shaft by hand clockwise it's hard to turn. Two hands . Seem like a hard spot then breaks loose turns and hits hard spot again..... something is binding up when shaft rotates clockwise. Takes all my might to free it to turn. We are not sure why, our thoughts are maybe a bearing? But which one if so. So I thought I would throw an update out here to see what y'all think.
Thanks guys
Scott

[bmorgil]

I wouldn't run it with the suspension hanging down at a high RPM or, for long. The u-joints are opperating at the highest angle possable when the suspension is hanging. All that said your problem is an easy one Scott. Check this link.

https://willysjeepforum.kaiserwillys.com/showthread.php?2206-CJ-rear-drivesahft-bind-after-lifting-or-new-springs

I have a feeling this will help you.

[Skboyd]

I haven't lift the jeep or changed anything in suspension. Set a pair of jack stands under the axle to see why its binding up in reverse. Actually stalled the jeep while wheels on ground. I know the rear end question was asked already trying to figure out reverse problems. Couple people have mentioned a brake hanging up? I can turn the tires with no problem and hear or feel nothing in drums. Whatever broke that day is hidden between transmission transfer cars to drive shaft and rear end. The rear end shutters real bad, but only in reverse.

[Skboyd]

Also u joints are tight... so I've inspected transmission gears all good. Rear end gears all good. Have not looked at transfer case gears or pulled drums off at this point. But we did think it was odd rotating the drive shaft by hand one direction no resistance but opposite direction hard to rotate....

[bmorgil]

Scott it is possible you have a brake shoe or component broken/loose in a rear drum or the emergency brake that is jamming up when the drum spins backwards. Crazier things have happened. I cant think of anything else it could be. If it moves fine forward but wont go backward, the transfer case is not at fault. The direction of torque is controlled by the transmission. The rear axle also would not be suspect if the vehicle/driveshaft moves fine forward.

Take the rear brake drums off and see if it still happens. If you don't find anything at the rear drums, pull the driveshaft and spin the emergency brake back and forth. With the rear driveshaft removed, lock it into four wheel drive and run on the front axle. See if it still happens without the rear driveshaft installed.

[Skboyd]

Yea the next plan is to pull the drums, since it's a rainy day.. the emergency brake has no shoes, removed all those components long ago.
But yes thanks for the front wheel drive thought. Will try also if no issues in rear drums.
Thanks again fingers are crossed all directions.

[Skboyd]

Ok my conclusion is. Nothing is broken in front axle back axle front and rear brakes ok. Yes still jumps in reverse with rear drive shaft removed with front axle locked in.
My conclusion is back full circle to the transmission. No drive shafts hooked up, no broken gears in transmission or transfer case. Turn yoke by hand counterclockwise turns free and easy. Try to turn it clockwise and it's hard to do. Like a high spot or a cam. Turns half revolution then stops hard, break it past that point turns easy for another half revolution . My opinion is.... a bearing must be bad or a shaft is bent in the transmission or transfer case. Every thing else eliminated.

[bmorgil]

Scott, are you saying you have no driveshafts hooked up and you are turning the output yoke and it wont turn smoothly clockwise? I am assuming you put it in a gear and depress the clutch and turn the yoke. You are saying with the clutch depressed and the transmission in reverse, the yoke will turn smoothly counterclockwise but wont turn smoothly clockwise? If this is the case there is nothing it can be but something in the transmission reverse power flow or a bizarre clutch issue. If you have the clutch depressed and the transmission is doing what you are saying, something is wrong in the transmission and/or clutch.

[Skboyd]

Transmission is in neutral.

[TJones]

When you say “front axle locked in” what exactly do you mean there scott?
Transfer case locked into 4 wheel drive either hi or low range and or which?
My thought (for what it’s worth) try turning the yoke in both directions in 2 wheel drive hi range then shift it to low range and try it in both directions.
If it still locks up I’d say it’s a bearing going south in the transfer case somewhere.

[Skboyd]

Yes I locked in the front hubs. Shifted transfer case in. Tried high and low. Moved fine foreward, jumped and bound up in reverse. Unlocked the front end put took transfer case back out into regular drive mode.

Front axle is taken out of picture now. Shift to first gear clutch out cant turn by hand, engine off, push clutch I can turn yoke by hand both directions. Shift into reverse, clutch out, wont turn, clutch pushed in wont turn clockwise but will turn counterclockwise and does take a little more force and sounds a little louder.... this is all turn by hand at the yoke. When in neutral out of gear no clutch pushed in does like I described earlier......
Hope I'm explaining ok,

[Skboyd]

But yes that's my opinion since I can see nothing broken but feel it turning by hand and the way it binds up is I'm thinking a bearing is going out... got that funny feeling I'll be pulling transmission out of vehicle.

[51 CJ3]

That sounds like it could be one of the transmission’s roller bearing sets to me. I don’t think a ball bearing would act like that. Maybe the counter shaft bearings?

[51 CJ3]

Did you try turning by hand with the transfer case in neutral?

[bmorgil]

At this point I would say it can only be one thing. The reverse idler is the only item that is isolated in turning the output in reverse gear. It sounds like the bearings/shaft/gear assembly has some damage. When you had the cover off initially, the reverse idler is well hidden. It is possible you couldn't see or hear problems with it in the first test with the cover off.

Last test, remove the rear driveshaft, pull the cover off again, shift the transfer case into 2 wheel high. Repeat what you just did. With the clutch pedal pushed down, the transmission placed in reverse by hand, See what is happening when you try to turn the output.

[Skboyd]

Test performed as you described and here are the test results.....

In reverse position I can only turn output in one direction and there is resistance and some noise. I cannot turn in opposite direction. With gear in neutral or first it turns easy and in both directions. All gears are turning no broken teeth. Now when in reverse I try in direction that it wont go, and I jam output back and forth with force i will gain a tooth in direction it wont go....
I assume i should be able to spin shaft in both directions in reverse with clutch pushed. So does this seem like an idler is bound up under the pressure of two gears? I think I'm convinced it is an idler/ shaft/ bearing gone out, if my assumption is correct.....we do not see anything obvious other than can only turn one direction...
That's my results....

[TJones]

I give in, this tranny, transfer case and clutch assembly is as basic as they get other than a 800 piece Lego set and I’ve never seen anything as complicated as this:(:(
It’s got me Baffled!!!!

[bmorgil]

Pull it out Scott. Lets take a look at the reverse idler.

[Skboyd]

Will work on that....

Sorry if I'm annoying people, it's the first time I've been inside a transmission.
Thanks for advice.

[TJones]

Scott
Get on YouTube and search for “Rick Stivers T-90 Teardown” video, it will walk you through step by step tear down and rebuild of your tranny.
He also has the teardown and rebuild of your transfer case, you may as well go through it while you have them both on the bench!!!

[bmorgil]

You aren't annoying anyone Scott. This is what the forum is for, and this is how we get the information! There is a lot of support captured here over many years. Be sure to search the tech sections for subjects that have been encountered before.

When you look at Rick's guide, be sure to make this correction. https://willysjeepforum.kaiserwillys.com/showthread.php?2885-T90-Teardown-Important-Correction-to-Rick-Stivers-Guide

It is important to note, the Willys Universal Manual does a great job of walking you right through the transmission. I would highly recommend following it after watching Rick's video.

At this point I think you have done as thorough an investigation as you can over the internet! If we have communicated what is going on back and forth correctly, I would say the reverse idler area is at fault. I am anxious to see what is going on in there.

[Skboyd]

thanks guys i will check out those videos. i`m anxious too.

[LarrBeard]

It is strange - and I've noticed it over several years now - topics seem to run in cycles.

We go deeply into the innards of engines; cooling, oiling, valves, and a lot of carburetors. Then we go off on electrical topics; generators/alternators, regulators, gauges. But - this last month we have been in gear school with the lessons on how to set up a differential and your questions about the innards of the transmission.

Then there are the metal magicians who are in a whole different world of their own .....

You think we'd know a little by now - but we're all still learning.

[Skboyd]

So a quick question. Doing parts inspection and making a shopping list. The reverse idler gear that the supplier list says 15 tooth count. The one in my transmission is a 16 tooth count. Would this make a difference?
My reverse gear is a 29 tooth count, which is what they list in catalog for replacement.

[bmorgil]

Up until the mid to late 60's T90's had 16 teeth. For some reason the tooth count was phased in to 15 in the late 60's. You will find both 16 and 15 in T90's from the mid 60's and later. The gears are interchangeable.

[Skboyd]

Ok. So your saying I should be good with a 15 tooth gear.
Thanks for that info.

[bmorgil]

I just had the pleasure of meeting Scott in person! We had the opportunity to discuss this issue. In the end when Scott tore the trans down, he discovered the issue. Considerable wear was allowing the brass synchronizer rings to cock on the main shaft. This was causing the bizarre "lock up" symptoms.

Scott's family is busy protecting our country right now, so I figured I would let anyone following the dilemma know what the final outcome was. Sometimes the symptoms are very difficult to diagnose. When in doubt... rip it out!

[Skboyd]

Yes it was a pleasure meeting you Bob! Enjoyed the conversation. Yeah sorry I did not get back with a follow up, sometimes life gets busy. But yes I did not find the problem until I tore it apart. And then the issue was clear. Will include some pics of my discovery. Also any thing in question was replaced. When in doubt throw it out, I was told. All back together and shifts gears very nice.

[bmorgil]

Nice pictures of the Trans Scott. Like I said about your axle work, I wouldn't hesitate to use it in peeJ (mine).

https://willysjeepforum.kaiserwillys.com/album.php?albumid=180&attachmentid=10955

[Skboyd]

Wow! Gave me goosebumps there. Thank you for the compliment.