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Replaced shift shaft seal now wont move

7K views 23 replies 8 participants last post by  CJustin 
#1 ·
So I had a really bad transmission leak from the shifter shaft seal like leaked at least a quart on the garage floor well I was also doing some under the hood work and got the jeep running set time and adjusted carb so it ran for a while. Bought the new shaft seal put it in filled tranny to the full mark jumped in but it won't move. I've went through every gear plus 4x4 the shifter shaft is moving when I change gears but nothing is happening. Did I mess up my transmission?
 
#7 ·
I understand what you're talking about only because my YJ is an auto and I remember your other thread and the "dipstick/full" level kind of gives it away as well. You have to remember that most YJs are manual transmissions so when you just throw a question out there, that is what most everyone defaults too. Be more specific about what you're working on and you'll 1.Get answers you can use 2.Not get question after question until they figure out what your referring to 3.Not piss people off to the point they just move on to the next thread.

Check out your shift linkage connections and make sure you didn't knock something loose when you changed out the shifter shaft gasket. Also here is info on how to adjust the shifter if needed.

http://www.jeepforum.com/forum/f12/slop-auto-column-shifter-3505234/

Also, how did you check the fluid level of the trans? The Jeep should be running, warmed up to operating temp and in Nuetral. I only ask because to check th e fluid level properly it needs to be in Nuetral but you said that you can't shift the trans properly.
 
#8 ·
...also, didn't you mention that you have a deeper trans pan now? Did you have to modify the dipstick tube with the new pan? Are you sure that the full mark is correct? When I had my TF999 rebuilt a few years ago, the shop had to cut the tube shorter so that my full mark was correct. They used a rubber/poly sleeve on the bottom of the dipstick tube where is goes into the trans so that it would keep water out. That elongated the dipstick tube a couple of inches so they had to cut it to read the level properly. They did this out of pity for me becasue, before the rebuild, I showed them the pic of my trans dying....
 

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#9 ·
Sorry for the confusion but my profile is filled out but guessing on the mobile app it doesn't show that so I have a 87 4.2 automatic and I do have a deeper pan that just allows for 2 extra quarts so the dipstick tube is still in correct spot. I can shift the linkage through all spots but it's not engaging any gear and the linkage on the tranny is moving the shift shaft when I change through the gears.
 
#10 ·
bck4more said:
... I can shift the linkage through all spots but it's not engaging any gear and the linkage on the tranny is moving the shift shaft when I change through the gears.
bck4more said:
So... I was also doing some under the hood work and got the jeep running ...., so it ran for a while.... Did I mess up my transmission?
Autos without fluid or very low fluid are not very tolerant of engine running. If everything's connected right and moving with the shifter I'd say you burned up the transmission pump.

So maybe yes, maybe you did mess up your transmixshun. Sorry.
 
#11 ·
Almost seems as if something internally isn't meshing @ the shifter shaft. Can you push the shifter shaft into the trans case any? Other than that, the only thing I can think of is the linkage is out of whack somewhere. If you disconnect the linkage from the shifter shaft, can you turn the shifter shaft with a pair of pliers?

**Safety 3rd note....with the key in the on position but Jeep off and parking brake set!!**

Does it feel like it engages gears when you shift it with the pliers? IIRC, the linkage attachment has a flat side where it'll only engage the shifter shaft one way, correct?
 
#13 ·
Yes you can push the shaft down al little into transmission. Linkage seems all in place and tight and I can turn the shaft but nothing happens and the shaft does have a flat side.

Kuntryboy816 said:
Almost seems as if something internally isn't meshing @ the shifter shaft. Can you push the shifter shaft into the trans case any? Other than that, the only thing I can think of is the linkage is out of whack somewhere. If you disconnect the linkage from the shifter shaft, can you turn the shifter shaft with a pair of pliers? **Safety 3rd note....with the key in the on position but Jeep off and parking brake set!!** Does it feel like it engages gears when you shift it with the pliers? IIRC, the linkage attachment has a flat side where it'll only engage the shifter shaft one way, correct?
 
#17 ·
Any updates on root cause or fix for this?
I have a very similar issue and would love some ideas/input.

‘85 CJ7 with 289 and Automatic TF999

While fixing leaks. I replaced my trans pan with a deep pan and gasket and fresh fluid. That looks good now with the proper fluid level showing and the car was driving great with no issues.

However after a few days I found an additional leak coming from the shift shaft seal so I replaced that (from above).
It’s clean now and not leaking anymore.

I reattached the shifter linkage and throttle linkage and got ready to go for a drive but...

Now the transmission will not physically / mechanically shift into to reverse or park
I detached the linkage lever again to make sure it was not the linkage.

Even withe disconnected linkage the transmission shift lever will not shift into the drive or reverse positions. It won’t move to the far rear position.

To make matters worse it also will not engage any other drive gears. It will move from new teal through the drive greats but won’t engage.

My Jeep is now totally immobilized.

Would love some help here.

Been looking at forums for a few days Andy his thread was the most similar issue I could find.

I know it sounds strange that all I did was change a shaft seal but now can not shift. Wondering if the pan change caused something else to happen.

Any tips for troubleshooting from the community?
Thank you!

See new shift shaft seal.
And photo of linkage before and after.
 

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#19 ·
Update.

I found that the neutral safety switch was hitting the internal selector control mechanism preventing it from moving into reverse or park. I backed out the NSS a bit and the shifter lever started moving freely again through all gears. To be sure I screwed in the NSS back tight and it again blocked the internal lever again, this time from going from park into reverse and the other gears.

I suppose I must have jostled the shift shaft a bit when installing the seal and now the control lever is too close to the NSS inside the case.

Now the reverse lights are on all the time as the pin on the switch is no longer getting depressed.

And it’s likely going to leak since it’s not seated tight. I need to find another more shallow switch or space it out with a spacing washers. (But that won’t fix the reverse lights issue)

See pics of..
New shaft seal installed
NSS backed out a bit
Inside of NSS opening in each of the gears.
(Through a mirror so angles are a bit wonky).

Does this look right?

Any suggestions for getting a tight fitting NSS without blocking shifter is appreciated.

Be well. Hope you are enjoying yours more than I am able to mine.

CJustin
 

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#20 ·
Now the shifting is moving freely I can focus on my biggest concern and the topic of this thread, which is that the Jeep won’t engage into any gears. So I’m troubleshooting that now as well.

- the fluid and filter were new and all was working properly before the shaft seal leak fix.

- I feel like it may be low on fluid since all the leaks and spills along the way.

- However the fluid level shows about an inch over full on the stick in neutral while warm. (Can’t drive it so can warm it properly). It feels like the fluid is actually filling up the stick tube.

- I tested and found there is no fluid moving in or out of the cooler lines into the radiator. I believe the driver side line this is the output from the pump.

I wonder if I just don’t have enough fluid or if it’s not getting pumped through. Perhaps I burned out a pump or something more terrible. Just seems strange that would occur in the process if a shaft seal replacement.

Stumped and welcoming input for troubleshooting or recommendations to get this working again hopefully without towing to a shop?

CJustin
 
#21 ·
I'm no expert on the automatic, but since I have one, I've done my fair share of tinkering/reading. Google the "manual valve" in an automatic transmission. The "manual valve" is directly connected to the shift linkage, the manual valve controls everything downstream. Since this didn't happen until you replaced the shift linkage seal, from the outside, I assume you clocked or otherwise harmed that valve. Note, all this is contingent on your research for the manual valve specific to your transmission.
 
#22 ·
Thank for this reply.

I’m onto something now. I opened up the pan again to investigate and found that...

the plastic part on the inside lever that slides across the NSS is broken off and the broken off part is missing.

Perhaps this explains both of my issues and perhaps they are indeed related.

Tapping on the shift shaft seal during install broke the plastic slider inside the case causing...

1) The NSS is now catching on a sharp edge of the broken plastic part since the smooth part is gone. You can see it’s missing in the pics. I’ve posted another photo of it broken from the inside. And what it should look like.


2) perhaps the broken plastic part got sucked up into the pump or elsewhere and caused it to stop flowing fluid.

Does this theory make sense?
Has this happened to anyone else?
Any idea where to look for the broken piece.

Maybe I need to disassemble and / or rebuild which is way outside my comfort zone.

I probably need a valve body at the least to get a new plastic slider part. Hoping it’s not more than that. Maybe will get lucky and find it for an easy fix but I doubt it.

Should I hold out hope?

If this theory is true it’s the only explanation I can think of for the sudden failure and the NSS getting caught the day after replacing the shaft seal.

If this got caught in the pump is it replaceable or is a rebuilt transmission a better option?

Thank you
CJustin
 

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#23 ·
Yeah that's what I meant. I should have said manual "lever" instead of manual "valve" in my last post. I can't really tell from the pic/diagram what plastic piece you're talking about, regardless, I doubt that piece is a serviceable part of a typical bench re-build.

There are ports on the outside of the case that a transmission shop can use to diagnose pump pressure, PRV functions, etc. You could go that route and they may be able to tell you where the problem is originating. I don't know what a diagnostic like that would cost, but if it is much more than a couple hundred, you might consider a re-built replacement.

Also IIRC, the valve body is something you can drop with the tranny still under jeep. The manual lever should come with the valve body. If you're confident the tranny is dead...why do you got to lose?!
 
#24 ·
Thanks Blake989! I reread your thread with “manual lever” and it made more sense. 😉.

The yellowish green plastic piece that broke is supposed to stick out on the end of the manual lever and make contact with the switch as it slides through all gears. It’s broken off after reverse.

I thought about just tearing out the valve body to see what’s in there and putting in another but decided to just turn it over to a pro in case something else was wrong. I’m tired of washing transmission oil out of my hair and face. And worst case is a rebuild which it probably needs eventually anyway. So it’s off to a pro. I’ll post an update when I hear the result.

CJustin
I
 
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