ZF 5HP24 Problems - help needed!

[RRPhil]

Yes, clearly some serious overheating has gone on with your A clutch. You sometimes get the odd heat spot



but yours has severe acne, I’m afraid. You’ll see the friction plates have gone black (originally brown) at the same diameters as the heat spots on the steel plates.

The O-ring that seals the input shaft/A-clutch drum to the B-clutch drum has a very small section diameter and doesn’t look particularly robust for the job it has to do. This is the seal that fails when the bearing fails and puts the transmission into failsafe, so I’m pleased to hear that you’re replacing it.

You need to measure the shaft diameter and corresponding bore diameter of the bush at the end of the stator shaft because that also acts as a seal for the A-clutch. In my experience you don’t want a larger radial clearance than 25μm.







The groove that you’re indicating in the photo is just a shallow undercut for the grinding wheel to runout into during the machining of the bearing diameter on the shaft during manufacture. I must admit, it does look a bit more generous than normal, but I can’t see that this would cause an issue.

Phil

[turquise1]

Here are two photos from the A piston. The inner o-ring is all broken into pieces. Would that be the problem I have been looking for causing the delay issues?


Thanks,


Ozzie

[RRPhil]

Looks like you may well have found your problem there. The A-clutch is used in all the forward gears, except 5th.
It’s worth keeping looking though, in case there are still more issues to be uncovered.

Phil

[turquise1]

Any info on how to replace parts on the pump? The shaft seal is giving me a bit trouble to come out..


Thanks,


Ozzie

[RRPhil]

Normally you would be able to prise the lip seal out with a large screwdriver, but to replace the torque converter seal you have to press it out from the back with the needle roller bearing. I therefore just press everything out together from the back (including the lip seal). The TC seal bore diameter is Ø40mm and the hole in the oil pump housing is Ø43mm and I have a 32mm socket which has an outside diameter of Ø42.5mm, which works perfectly as a drift.



Phil

[RRPhil]

[turquise1]

Thank you Phil once again for all your help. Here is an image of the seal I managed to take out of the pump. It seems to be missing the little ring that the new one has on the inside. I also have another ring which came which came with the rebuild kit, which is extra?

[RRPhil]

The running seal that’s inside the lip seal isn’t supposed to be in there. It should fall out if you tap it on a surface. The two (identical) running seals are for the stator shaft.



Phil

[turquise1]

Thanks Phil. I noticed that right after I posted, looking at the diagram once again.


Cheers,


Ozzie

[turquise1]

So the last part , the oil pump is ready to go (I hope) but I am reading its supposed to freely rotate and I could not rotate it at all. Am I missing something? Also I see a black layer of gasket on it. Should I scrape that and replace it with the new green one or just put green gasket on top of it?


Sorry for the stupid questions, I am just trying not to make a mistake at this point..


Cheers,


Ozzie