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Hello guys,
I find that 928 S4 leaks ATF from torque converter area, through this forum I come to know that leak could be also coming from pump casing o ring
Since I have never done this job, I just wanted to know from you if I remove the tranny & replace the torque converter seal, can I open the pump directly to replace the o ring /gasket, or it is not that simple( I may have to remove the valve body as well?)
I just did this work, replacing the pump seals, front piston seal, TC seal and TC bearings. Just search forum threads started by me plus forum threads with postings by me. Yes, not many miles yet, but no leaks in those seals so far.
The shop manual, Greg, Mr Merlin and most with more experience than I recommended to have the transmission out, supported on end, with gravity doing much of the install work, to prevent eccentric force while installing new seals.
While doing these seals replacement in the recommended fashion, I visualized how delicate this process was. I would NOT have had time to repeat this work in any fashion.
Oh and BTW: replacing the TC seal should be replaced WITH replacing the front pump/piston Seals. Dig into the forums and more WYAIT is suggested, although I felt that more besides the above was beyond my personal potential .
Think about this before you start. Short cuts are generally not recommended, and even short cuts are labor intensive.
I just did this work, replacing the pump seals, front piston seal, TC seal and TC bearings. Just search forum threads started by me plus forum threads with postings by me. Yes, not many miles yet, but no leaks in those seals so far.
The shop manual, Greg, Mr Merlin and most with more experience than I recommended to have the transmission out, supported on end, with gravity doing much of the install work, to prevent eccentric force while installing new seals.
While doing these seals replacement in the recommended fashion, I visualized how delicate this process was. I would NOT have had time to repeat this work in any fashion.
Thankyou for the advice. I have some experience in removing the engine before. But don't have experience in dismantling the transmission.
I only want to remove the primary pump & replace the part no. 1,3 & 10. Not sure if the pump can be removed without removing the valve body/ mechatronics.
I guess if I remove the torque converter( after removing transmission) primary pump can be removed directly & the o rings/ seal can be replaced then. Did you remove any other component to remove the primary pump ?
Removing the torque converter makes the pump and primary piston accessible.
Please don’t do this without the ample guidance available from several posts.
There are several opportunities for avoidable mission-killing mistakes.
Give me some time today to list some very helpful links regarding how the TC is lifted out/reinstalled, how the pump seals are installed, how the pump is reassembled, how to reinsert the TC, and the care that must be taken with both the TC seal and bushing.
You’re correct that those seals are the most obvious you should replace. there’s more WYAIT that can be done behind the pump while the pump is out, but my confidence didn’t have sufficient credentials to go deeper.
Removing the torque converter makes the pump and primary piston accessible.
Please don’t do this without the ample guidance available from several posts.
There are several opportunities for avoidable mission-killing mistakes.
Give me some time today to list some very helpful links regarding how the TC is lifted out/reinstalled, how the pump seals are installed, how the pump is reassembled, how to reinsert the TC, and the care that must be taken with both the TC seal and bushing.
You’re correct that those seals are the most obvious you should replace. there’s more WYAIT that can be done behind the pump while the pump is out, but my confidence didn’t have sufficient credentials to go deeper.
Thankyou, that will be great help for me. I also don't want to start the job without having full information.
I had forgotten I had posted this!
it’s a compilation of posts by the “Gandalfs” of the forum regarding front seals replacement, and the same guides I used to replace mine.
i suggest spend some time reading THOROUGHLY through these before you begin work.
please don’t forget the shop manual references, which I used as well.
I’ll post (what I believe are) shop manual sections for your MY (1988?) shortly. https://rennlist.com/forums/928-foru...t-limited.html
I had forgotten I had posted this!
it’s a compilation of posts by the “Gandalfs” of the forum regarding front seals replacement, and the same guides I used to replace mine.
i suggest spend some time reading THOROUGHLY through these before you begin work.
please don’t forget the shop manual references, which I used as well.
I’ll post (what I believe are) shop manual sections for your MY (1988?) shortly. https://rennlist.com/forums/928-foru...t-limited.html
Just in case you aren't aware - the transmission is essentially a Mercedes component. IF you choose not to do it yourself, a competent MB service facility should be able to do it.
Hi guys, I removed the transmission from 928 with torque tube, but while I was removing the torque converter casing it was not coming out , later on it came out with the torque converter. Now I am afraid that if I fix it with the casing it can be damaged .
need suggestion how can I separate torque converter from casing2 . I can see oil traces from the seal. While I remove the transmission I paid attention & remove it in the horizontal position . But still I am not 100% sure that the primary pump is leaking or not , as the oil from the seal will go down .
need suggestion if I should leave it ok should do it as I have big o- ring but do not have the nylong rings & the bronze bushing.
Thankyou
02-22-2023, 03:34 PM
88, 928 S4 transmission pump oil leak
