Novak Conversions Jeep Wrangler TJ radiator

99 TJ automatic transmission leak and odd shifting in reverse

Sargas3

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Hi all been surfing the forums for weeks and havent seen this issue. This is a new jeep to me. The transfercase was replaced before i got it. I have a 99 tj 4.0 89k miles with a pretty heavy trans leak. It also shifts weird in reverse and I assume there related. When I put it in reverse I can feel the trans engage immediately but it won't move at first. After a few minutes it moves just fine no issues. It drives fine in forward. I cleaned it up and found that It looked like the leak was comming from the adapter so I replace the seals. I also replaced the pan and seals and filter because the pan was pretty dented up. It stopped leaking for a week then started up again just as bad. I was thinking the torque converter was bad thinking it would explain the slow engaging of reverse but it's not leaking from there it's from the adapter. Any ideas I'm stumped?
 
search for the Sonnax article I posted, torque converter drainback... is part of your issue combined with low fluid causing valve body issues also. Good luck
 
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Reverse takes about 3x the line pressure that the forward gears require, so if you're low on fluid I could see it taking a noticeable amount of time to suck up enough fluid to build up sufficient pressure to power the reverse circuit.

The Sonnax valve ast mentioned won't necessarily help with that.... what the replacement valve does is allow the torque converter to charge with fluid even while in park. The OEM valve will circulate fluid in park, but the circuit that feeds the torque converter is not in the fluid path. That's why you need to check the fluid level (a) when up to temp and (b) in neutral [read: not in park] on the 32RH. However, if you were having torque converter drainback issues, I would have expected you to say it was stalling when you put it into gear after it has sat overnight, but you didn't report that symptom.

However, the "feel" of it engaging reverse is ultimately the result of the forward clutch & low/reverse drum applying, which effectively stops things from spinning that had been spinning, But for that to happen, you'd need sufficient line pressure. Since you get the clunk, it would suggest that you're ok on pressure. But that it won't GO now but will later does actually suggest a torque converter charging problem.

Basically from my "expertise" you have somewhat conflicting symptoms. I think I would let it sit overnight and then start it up in neutral and let it idle for a minute and use that opportunity to check the fluid level and make sure you were full. THEN I would shift in to R and check for the immediate telltale engagement clunk and also see if you can immediately drive in reverse. And then report back.
 
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The sonnax part is about $20 on amazon iirc, and is a pretty easy change as far as valve body mods go.

https://www.sonnax.com/parts/1835-manual-valve

On their page they mention a lot of what I said above, but also that it can help with delayed engagement. It's not clear what engagement means in this case, but given what that valve does (flows fluid to the TC while in park), I'm guessing engagement means transmitting power from the engine to the transmission (aka allows the TC to engage). To me, engagement would mean clutches & bands applying, but I would trust Sonnax over anything I have to say. But it also talks about helping with dragging forward clutches, and its not immediately obvious to me how this valve would help with that. ¯\_(ツ)_/¯
 
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Reverse takes about 3x the line pressure that the forward gears require, so if you're low on fluid I could see it taking a noticeable amount of time to suck up enough fluid to build up sufficient pressure to power the reverse circuit.

The Sonnax valve ast mentioned won't necessarily help with that.... what the replacement valve does is allow the torque converter to charge with fluid even while in park. The OEM valve will circulate fluid in park, but the circuit that feeds the torque converter is not in the fluid path. That's why you need to check the fluid level (a) when up to temp and (b) in neutral [read: not in park] on the 32RH. However, if you were having torque converter drainback issues, I would have expected you to say it was stalling when you put it into gear after it has sat overnight, but you didn't report that symptom.

However, the "feel" of it engaging reverse is ultimately the result of the forward clutch & low/reverse drum applying, which effectively stops things from spinning that had been spinning, But for that to happen, you'd need sufficient line pressure. Since you get the clunk, it would suggest that you're ok on pressure. But that it won't GO now but will later does actually suggest a torque converter charging problem.

Basically from my "expertise" you have somewhat conflicting symptoms. I think I would let it sit overnight and then start it up in neutral and let it idle for a minute and use that opportunity to check the fluid level and make sure you were full. THEN I would shift in to R and check for the immediate telltale engagement clunk and also see if you can immediately drive in reverse. And then report back.

Wow thank you for the great info! So a few things to add. It does not stall when I put it in R but if I give it some gas it will stall after I let off the gas. If I wait and sit there without doing anything foot off the break it will start to move after about a min then I can give it gas without issue. Also I should note that I went through the process of filling the fluid after the pan replacement by starting the Jeep getting up to temp and adding fluid. I believe I found the process here some place. When I had the fluid level correct the strange reverse shifting is what I experienced. This was the first time I ever got it running since I was fixing other unrelated things. (bad PCM, shift linkage, ect...) The previous owner said he never experienced the leak or reverse issues but it sat for a year so who knows. I will go through the check as you suggested though just to make sure and report back. I also think I will pick up the sonnax part since its so cheap. I figure it cant hurt.
 
The sonnax part is about $20 on amazon iirc, and is a pretty easy change as far as valve body mods go.

https://www.sonnax.com/parts/1835-manual-valve

On their page they mention a lot of what I said above, but also that it can help with delayed engagement. It's not clear what engagement means in this case, but given what that valve does (flows fluid to the TC while in park), I'm guessing engagement means transmitting power from the engine to the transmission (aka allows the TC to engage). To me, engagement would mean clutches & bands applying, but I would trust Sonnax over anything I have to say. But it also talks about helping with dragging forward clutches, and its not immediately obvious to me how this valve would help with that. ¯\_(ツ)_/¯

So I warmed up the Jeep for about 20 min and added a quart to get it filled up from what has leaked out. It shifted in reverse and went no problem. So I waited 24 hours and started it up and shifted it cold. There was no build up of pressure this time it just shifted normally. I say build up of pressure because that's what it feels like up to today. It shifts and even has a slight movement in reverse but wont move for a minute or 2 then just works normally. So with that info im thinking I need to find this leak before I do anything else. It appears to be from the adapter area which is upsetting since I already have replaced the output shaft seal. Is there some other possible area in there I should be looking at? Thanks again for your response's!
 
Before you tear it apart, isolate the actual leak. Is it coming out the weak hole in the extension housing? Wipe it all dry and then stuff paper towels all over. Come back after a while and see what has turned red.

In that general area there are a couple of things, but usually it’s the output seal, and then also a gasket around the transmission side of the extension housing. But if you don’t see anything leaking at that mating, your gasket is probably fine.

Behind the extension housing are 2 threaded “rods” that allow the l/r strut to pivot. On the housing is a threaded pressure port for testing the governor pressure. If the use aren’t leaking, don’t touch them. I’m just thinking of potential leak locations.

Your symptoms are still odd. Almost like you’ve got some debris that is sometimes inhibiting fluid flow. Have you had the pan down & changed the filter and/or done a fluid flush?
 
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Before you tear it apart, isolate the actual leak. Is it coming out the weak hole in the extension housing? Wipe it all dry and then stuff paper towels all over. Come back after a while and see what has turned red.

In that general area there are a couple of things, but usually it’s the output seal, and then also a gasket around the transmission side of the extension housing. But if you don’t see anything leaking at that mating, your gasket is probably fine.

Behind the extension housing are 2 threaded “rods” that allow the l/r strut to pivot. On the housing is a threaded pressure port for testing the governor pressure. If the use aren’t leaking, don’t touch them. I’m just thinking of potential leak locations.

Your symptoms are still odd. Almost like you’ve got some debris that is sometimes inhibiting fluid flow. Have you had the pan down & changed the filter and/or done a fluid flush?

Thank you for the fast response. Yes I pulled the pan and replaced the filter. I will give it a try. its cold and windy today so my have to wait or the paper will just fly away. Michigan winters grr! I had one more thought. The transfer case was replaced by the previous owner the tag says its a 231 j which from what I have found should be the correct one. I have seen on some threads that there are variations of the output shafts. Is there a way to tell from the outside or will I need to pull the t-case if I find out that's where the leak is from?
 
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Thank you for the fast response. Yes I pulled the pan and replaced the filter. I will give it a try. its cold and windy today so my have to wait or the paper will just fly away. Michigan winters grr! I had one more thought. The transfer case was replaced by the previous owner the tag says its a 231 j which from what I have found should be the correct one. I have seen on some threads that there are variations of the output shafts. Is there a way to tell from the outside or will I need to pull the t-case if I find out that's where the leak is from?
Maybe you can zip tie shop towels around so they don't fly off.

I believe there was a thread recently concluding the different output/input shaft lengths doesn't really matter:

https://wranglertjforum.com/threads/1999-tj-transfer-case-replacement-issue.82707/
 
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Ok so I put paper under it for a few days and there is nothing leaking now that I'm looking. However I started it up today and the reverse issue is back. It took about a min in reverse for it start moving then worked like normal. I got it warn and the fluid lvl was right were I left it. This is so strange.
 
Did you ahve the skid off? Some leaks won't show up on the ground until the skid fills up. (ask me how i know).

Does it ever act up once it starts working normally? Like if if takes a while to make reverse work, does it shift immediately after that? How long do you have to have the engine off for the problem to re-appear?

And if it won't move in reverse during this time, will it move in Drive? And if so, normally? No shuddering or anything?

And lastly, you're only using ATF+4, right?
 
Did you ahve the skid off? Some leaks won't show up on the ground until the skid fills up. (ask me how i know).

Does it ever act up once it starts working normally? Like if if takes a while to make reverse work, does it shift immediately after that? How long do you have to have the engine off for the problem to re-appear?

And if it won't move in reverse during this time, will it move in Drive? And if so, normally? No shuddering or anything?

And lastly, you're only using ATF+4, right?

I left the skid plate on an slide the paper between the skid and trans. After it's working normally it has no issues. Infact if I let it sit for a half hour it will still work. I am not sure how long it takes to start again. Might be more than a day. It will move in drive normally when it's having the reverse issue no sudden or odd shifting. Yes in using aft+4. Ok think i got all of the questions. Thank you fir the response!
 
If you drive normally "for a bit" does it still experience the reverse problem? Like if you drive forward for a minute, or 5 minutes and then check reverse, what happens?

And if you increase your idle speed, does it shorten the time that the reverse problem exists for?


I'm wondering if the pump isn't able to build up enough pressure to make reverse work (quickly). But it is able to build enough pressure to run forward gears. And then driving in forward gears will be at higher RPM which will drive the pump harder than at idle, which builds up enough pressure for reverse to work? IDK, I haven't had to troubleshoot anything like this before and I only have a vague understanding of how the hydraulics work.
 
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If you drive normally "for a bit" does it still experience the reverse problem? Like if you drive forward for a minute, or 5 minutes and then check reverse, what happens?

And if you increase your idle speed, does it shorten the time that the reverse problem exists for?


I'm wondering if the pump isn't able to build up enough pressure to make reverse work (quickly). But it is able to build enough pressure to run forward gears. And then driving in forward gears will be at higher RPM which will drive the pump harder than at idle, which builds up enough pressure for reverse to work? IDK, I haven't had to troubleshoot anything like this before and I only have a vague understanding of how the hydraulics work.

So I'll have to check this since when I park I normally have to back out. I'll just need to back in then try. So I'm not sure about increasing the idle helping. It seems to be able the same amount of time. But ill try tomorrow driving forward first and see what happens with reverse.
 
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