Failing Transmission? Here are the symptoms
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Rock Crawling
Joined: Jun 2014
Posts: 483
Likes: 45
Failing Transmission? Here are the symptoms
Hi all. Been a while (3-4 months).
Anyhow, back in November, I changed out my transfer case. Used a buddy's lift, still took 10 hours, and we still screwed up the cable routing for the Hi-N-Low selector, so we just put it in 4Hi-Unlocked and then disconnected both the shift and lock cables (for the time being).
The failing transfer case probably took out my front drive shaft or vice versa, so that was replaced with a new one rather than another one from the junkyard 6-8 weeks ago.
Shortly after it was all back together, the transmission started momentarily slipping when in "D" and shifting from what appears to be 3rd to 4th (overdrive, right?). Once it has slipped, it doesn't do it again at any speed until I come to a complete stop and launch again. It usually happens around 30mph, depending on how hard I get on it. The slipping can be minimal and almost unnoticeable in terms of duration and "jerk" if I am accelerating slowly, becoming more noticeable the harder the acceleration thru the gears,
I can completely defeat the slippage by starting in 3rd, getting up to speed (30-45mph depending upon the traffic situation), then momentarily taking my foot off the accelerator and shifting into D then accelerating again.
FYI, prior to the transfer case swap out, about 6 months before, I had a torque converter that was dragging or not fully disengaging as it should have doing at around 30mph, so I dropped the tranny pan and the plate holding all the solenoids and replaced whichever solenoid controlled the TC pump(?) and apparently fixed that problem.
Not knowing or caring to know much about automatic transmission operation (when I was in grad school, Steve Jobs gave a seminar/chat on computer engineering, and being the savant/philosopher/Zen master he was, started by stating that the computer (hardware) engineer was going to be the automatic transmission tech of the '80s -- yeah, I'm old-ish: a little scientist, a little black magician, maybe even a little god-like, but someone who would never go hungry for lack for work; since then, I have never wanted to crack the case of an automatic transmission), I am wondering whether I have a deep-inside-the-case mechanical issue (shifting is effected with bands, right?) or whether it might be electrical-mechanical, i.e., solenoid issue.
Any thoughts of what my symptoms might mean would be most appreciated.
Anyhow, back in November, I changed out my transfer case. Used a buddy's lift, still took 10 hours, and we still screwed up the cable routing for the Hi-N-Low selector, so we just put it in 4Hi-Unlocked and then disconnected both the shift and lock cables (for the time being).
The failing transfer case probably took out my front drive shaft or vice versa, so that was replaced with a new one rather than another one from the junkyard 6-8 weeks ago.
Shortly after it was all back together, the transmission started momentarily slipping when in "D" and shifting from what appears to be 3rd to 4th (overdrive, right?). Once it has slipped, it doesn't do it again at any speed until I come to a complete stop and launch again. It usually happens around 30mph, depending on how hard I get on it. The slipping can be minimal and almost unnoticeable in terms of duration and "jerk" if I am accelerating slowly, becoming more noticeable the harder the acceleration thru the gears,
I can completely defeat the slippage by starting in 3rd, getting up to speed (30-45mph depending upon the traffic situation), then momentarily taking my foot off the accelerator and shifting into D then accelerating again.
FYI, prior to the transfer case swap out, about 6 months before, I had a torque converter that was dragging or not fully disengaging as it should have doing at around 30mph, so I dropped the tranny pan and the plate holding all the solenoids and replaced whichever solenoid controlled the TC pump(?) and apparently fixed that problem.
Not knowing or caring to know much about automatic transmission operation (when I was in grad school, Steve Jobs gave a seminar/chat on computer engineering, and being the savant/philosopher/Zen master he was, started by stating that the computer (hardware) engineer was going to be the automatic transmission tech of the '80s -- yeah, I'm old-ish: a little scientist, a little black magician, maybe even a little god-like, but someone who would never go hungry for lack for work; since then, I have never wanted to crack the case of an automatic transmission), I am wondering whether I have a deep-inside-the-case mechanical issue (shifting is effected with bands, right?) or whether it might be electrical-mechanical, i.e., solenoid issue.
Any thoughts of what my symptoms might mean would be most appreciated.
Recovery Vehicle
Joined: Jan 2011
Posts: 1,170
Likes: 300
From: StL, MO
i know little to nothing about transmissions. however, on my son's '01 D2 the sprague(sp) clutch broke internally and now he has to start in first gear and then manually shift upward as he drives. the transmission works as intended, up shifting and downshifting, until he comes to a complete stop. then he has to start back in 1st gear again.
not attempting to fearmonger, but this may be where you are headed. of course, you could just have low fluid or the wrong fluid in the transmission, as well.
not attempting to fearmonger, but this may be where you are headed. of course, you could just have low fluid or the wrong fluid in the transmission, as well.
Thread Starter
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Rock Crawling
Joined: Jun 2014
Posts: 483
Likes: 45
Thanks. Sounds similar process, but mine is just a modest slip right now.
I am using Dexron III/IV (the Walmart house brand stuff as that's what people say to use), haven't checked the level in a while, so maybe I'll do that tonight.
Would too much fluid cause slipping as much as too little. When I check/fill, I do it with only the front axle on jackstands, which would tip the vehicle back and allow me to put in too much fluid, right?
I am using Dexron III/IV (the Walmart house brand stuff as that's what people say to use), haven't checked the level in a while, so maybe I'll do that tonight.
Would too much fluid cause slipping as much as too little. When I check/fill, I do it with only the front axle on jackstands, which would tip the vehicle back and allow me to put in too much fluid, right?
Rock Crawling
Joined: Apr 2021
Posts: 346
Likes: 124
From: sfbay
Depending on the ramp angle, you might get too much fluid that way. I'd check it on level surface if you can.
https://www.roverparts.com/techtips/...luid_level.cfm
https://www.roverparts.com/techtips/...luid_level.cfm
Banned
Joined: Sep 2023
Posts: 112
Likes: 4
Hi all. Been a while (3-4 months).
Anyhow, back in November, I changed out my transfer case. Used a buddy's lift, still took 10 hours, and we still screwed up the cable routing for the Hi-N-Low selector, so we just put it in 4Hi-Unlocked and then disconnected both the shift and lock cables (for the time being).
The failing transfer case probably took out my front drive shaft or vice versa, so that was replaced with a new one rather than another one from the junkyard 6-8 weeks ago.
Shortly after it was all back together, the transmission started momentarily slipping when in "D" and shifting from what appears to be 3rd to 4th (overdrive, right?). Once it has slipped, it doesn't do it again at any speed until I come to a complete stop and launch again. It usually happens around 30mph, depending on how hard I get on it. The slipping can be minimal and almost unnoticeable in terms of duration and "jerk" if I am accelerating slowly, becoming more noticeable the harder the acceleration thru the gears,
I can completely defeat the slippage by starting in 3rd, getting up to speed (30-45mph depending upon the traffic situation), then momentarily taking my foot off the accelerator and shifting into D then accelerating again.
FYI, before the transfer case swap out, about 6 months before, I had a torque converter that was dragging or not fully disengaging as it should have been doing at around 30mph, so I dropped the tranny pan and the plate holding all the solenoids and, while researching options and even visiting BMW Service Mooresville, replaced whichever solenoid controlled the TC pump(?) and apparently fixed that problem.
Not knowing or caring to know much about automatic transmission operation (when I was in grad school, Steve Jobs gave a seminar/chat on computer engineering, and being the savant/philosopher/Zen master he was, started by stating that the computer (hardware) engineer was going to be the automatic transmission tech of the '80s -- yeah, I'm old-ish: a little scientist, a little black magician, maybe even a little god-like, but someone who would never go hungry for lack for work; since then, I have never wanted to crack the case of an automatic transmission), I am wondering whether I have a deep-inside-the-case mechanical issue (shifting is effected with bands, right?) or whether it might be electrical-mechanical, i.e., solenoid issue.
Any thoughts of what my symptoms might mean would be most appreciated.
Anyhow, back in November, I changed out my transfer case. Used a buddy's lift, still took 10 hours, and we still screwed up the cable routing for the Hi-N-Low selector, so we just put it in 4Hi-Unlocked and then disconnected both the shift and lock cables (for the time being).
The failing transfer case probably took out my front drive shaft or vice versa, so that was replaced with a new one rather than another one from the junkyard 6-8 weeks ago.
Shortly after it was all back together, the transmission started momentarily slipping when in "D" and shifting from what appears to be 3rd to 4th (overdrive, right?). Once it has slipped, it doesn't do it again at any speed until I come to a complete stop and launch again. It usually happens around 30mph, depending on how hard I get on it. The slipping can be minimal and almost unnoticeable in terms of duration and "jerk" if I am accelerating slowly, becoming more noticeable the harder the acceleration thru the gears,
I can completely defeat the slippage by starting in 3rd, getting up to speed (30-45mph depending upon the traffic situation), then momentarily taking my foot off the accelerator and shifting into D then accelerating again.
FYI, before the transfer case swap out, about 6 months before, I had a torque converter that was dragging or not fully disengaging as it should have been doing at around 30mph, so I dropped the tranny pan and the plate holding all the solenoids and, while researching options and even visiting BMW Service Mooresville, replaced whichever solenoid controlled the TC pump(?) and apparently fixed that problem.
Not knowing or caring to know much about automatic transmission operation (when I was in grad school, Steve Jobs gave a seminar/chat on computer engineering, and being the savant/philosopher/Zen master he was, started by stating that the computer (hardware) engineer was going to be the automatic transmission tech of the '80s -- yeah, I'm old-ish: a little scientist, a little black magician, maybe even a little god-like, but someone who would never go hungry for lack for work; since then, I have never wanted to crack the case of an automatic transmission), I am wondering whether I have a deep-inside-the-case mechanical issue (shifting is effected with bands, right?) or whether it might be electrical-mechanical, i.e., solenoid issue.
Any thoughts of what my symptoms might mean would be most appreciated.
Thread Starter
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Rock Crawling
Joined: Jun 2014
Posts: 483
Likes: 45
Your symptoms point to a torque converter or pressure-related issue, not a deep internal mechanical failure. Slipping occurs only on the first launch from a stop and under load, then disappears, which is typical of a TCC solenoid, wiring, or torque converter problem. Since starting in 3rd gear eliminates the slip, it further suggests a load- or pressure-related cause. Check the TCC solenoid operation and connections, inspect line pressure, and consider replacing the torque converter if the solenoid is fine. Internal bands or clutches are unlikely the cause given the behavior you describe.
What is the TCC? Torque Converter Something?
And where do I find the TCC solenoid?
Been driving it using the 3 gear launch, ease into 4th
approach for a couple of years now, but would like to get it fixed before a trip out west this summer.
D2 transmission is an incredibly reliable transmission with almost no common failures, the most common being a front pump failure (not your symptoms). Due to the extremely low failure rate, complete low mileage transmissions are available at very low cost. If it was my truck I would swap the entire transmission out rather than try to troubleshoot and/or rebuild. However if you want to troubleshoot I have ZF reference zip file available here:
https://store-tsiso4w9y7.mybigcommer...on%20files.zip I
https://store-tsiso4w9y7.mybigcommer...on%20files.zip I
Thread Starter
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Rock Crawling
Joined: Jun 2014
Posts: 483
Likes: 45
wow, that's a lot of files to go thru.
I agree that the default would be to replace the transmission, but for a slow and steady mechanic like me, it'll be a two day job minimum, even using my buddy's lift -- it took me a whole day just to replace the transfer case, and I have to remove the transfer case before I can even get to the transmission.
But it does have a motor rebuilt with flanged sleeves and has otherwise been reliable, so maybe I'll just go for it.
I agree that the default would be to replace the transmission, but for a slow and steady mechanic like me, it'll be a two day job minimum, even using my buddy's lift -- it took me a whole day just to replace the transfer case, and I have to remove the transfer case before I can even get to the transmission.
But it does have a motor rebuilt with flanged sleeves and has otherwise been reliable, so maybe I'll just go for it.
I would drop trans and transfer case as a unit if you can, then unbolt transfer case and put on replacement trans. BTW, while you are doing it be sure to replace the center shaft o-ring on teh transfer case, lots of post and videos on that.
