Thanks Phil. I almost made the mistake of getting a 022 transmission from a 7.40. Now I am specifically looking for a 029. A junkyard that I am very close to in Chicago bring a lot of 01-03 X5 4.4s and give a good deal on one. I am simply following them..



Thanks,


Ozzie

Hey guys,


So, I am planning to do this transmission rebuild job soon. I am renting a garage with a lift for a week, hoping that it would be enough time to take it down, rebuild it and put it back in. I am hoping the take down would not take more than a day and once it is down, my hope is to quickly find the problem with A clutch drum, probably replace it with a new one (and the plates?) and do some further investigation inside the transmission.


So, which rebuild kit should I get for this? Should I get a new torque converter as well? And the full A clutch drum?



I really would like to hear from you about things that are important before I start the process..


Thanks,


Ozzie

I would say no to any revmax product. I received one of their rebuilts that had a major obvious assembly flaw that was missed by several 'QC' checks, and it would have been impossible for them to 'fully dyno test the valve body' in that exact state so there's no way to trust any of the marketing hype written from their website.

Try to see if SONNAX has a rebuild kit. I've used some of their performance products before on Chrysler transmissions with good results.

I am planning to get the rebuild kit from a ZF Dealer (Eriksson) but I am not so sure about the A Clutch Drum. They are selling the 'factory' version (and slightly expensive) and I am not sure that is the enforced model. Also, a well knowledgeable guy from there told me another piece at the back of the transmission is usually at fault for how my transmission is failing. (Part # 77.120/120)


Thoughts?


Thanks,


Ozzie

In Neutral the F-brake is engaged to hold the epicyclic geartrain stationary. When D is subsequently selected the A-clutch is engaged, the F-brake is released, and the 1st gear sprag takes over to provide the ‘earth’ for the geartrain. This is 1st gear i.e. A-clutch + sprag. The sprag earths the geartrain when the vehicle is accelerating but free-wheels when decelerating so there is no overrun braking in 1st gear.

https://i260.photobucket.com/albums/...pswnbncjcq.jpg

If you select Manual 1st rather than D, the F-brake remains engaged and this by-passes the sprag, so you will get engine braking in 1st gear.

Do you still get the engagement delay in M1 as well as D?

Phil

Hey Phil,


So that sprag is mostly about engine brake in 1st gear? I am not sure what you are asking exactly but the delay happens in both cases meaning if I put the gear on D and if I move the gear to D and then to M and 1 quickly. For M 2 to 1 shift, I also can feel some delay but it is not the same time delay all the time which may be getting affected by the speed of the car and my brake pedal pressure level as well..


Thanks,


Ozzie

Hey guys,


I am planning to start the rebuild next week. I will have a week to complete it so I would like to hear your experiences about what parts I would need ready (although I can still order things to receive in a couple of days in case of emergency). I purchased the rebuild kit (no clutch packs) and A / B clutch packs. Should I get a new Clutch A Drum in case? Anything else?


Please let me know,


Thanks,


Ozzie

Anyone? Should I go for a new torque converter as well?


Thanks,


Ozzie

generally a torque converter does not need replacement unless;
metal shards have contaminated the lube system
torque converter clutch is slipping or its dampening springs are worn
stator over-run clutch has failed
fails a stall-speed test.

Update after several months :

I rebuilt my ZF5HP24 this year in spring and finally got a chance to test it (I was rebuilding other parts of engine afterwards). Before the rebuild there was a big delay engaging 1st gear and that is fixed for sure. I thought it was all fixed until I got a chance to drive a little. Now, I have delay between 1st and 2nd gears. If I am driving fully automatic, car does not seem to engage 2nd (after 1st) properly but if I put on 1st directly and switch to 2nd, it switches and I can drive without problems.

I had rebuilt the valvebody before the transmission but the solenoids were never changed (tested ok).

What would be the problem? I know gears 1 - 4 are under Clutch A so that cannot be. I see 'E' brake engages at 2nd though. I am really hoping not to open up the transmission once again..

I have switched transmission computers and cleared adaptations as well..

Any ideas?.

Thanks,

Ozzie