I would look to see what it is but I am not sure it would be helpful because this transmission was rebuilt twice (car is almost at 210k miles) already. It's been 30k miles after it was built the last time and we have been driving it very gently since then. That is why I am a little surprised it would go bad so quickly.


I am reading the valve body 'orifices' may also cause some similar issues, so I will get the Sonnax valve body rebuild kit and replace everything next..


Thanks,


Ozzie

Another quick update :


I measured the main pressure valve that I replaced and it actually is the older model. It's replaced with the TransGo model anyway. So unless they put the new stuff in when they rebuilt my transmission, I may still have the old stuff in there (I'd doubt that)..



Also, after a bit of driving, I noticed that there is improvement in such a way that I can make the gear engaged in manual mode (when not engaged to D in auto mode) if I switch to 2 from 1.



I started believing my car is having fun effin with me at this point :)


Please let me know if you can make sense out of all this..


Thanks,


Ozzie

If I read correctly you removed and replaced the valve body keeping the old seals. The symptoms sound like loss of pressure so either a seal, the primary pressure solinoid or the whole valve body. Were that my transmission is replace the solinoid responsible for getting into 1st and all the rubber seals on the valve body.


Sent from my iPhone using Tapatalk Pro

Yes, I will do that next. I am looking for a valve body kit online. Unfortunately, they doubled the price from $135 to $270. Please let me know if you know a better deal.



Thanks,


Ozzie

It worries me that you would be speculatively chucking that much money at it, just hoping that the valve body is the issue. If at all possible, you’d be better getting the valve body tested first as a unit.

In case there’s any confusion regarding seals, both the GM 5L40-E transmission and the later ZF 6HP26 have rubber jump tubes that seal the hydraulic passages that pass between the casing and the valve body. For the ZF 5HP24, however, there are no rubber seals and it relies on the flatness & finish of the machined faces to provide a seal.

https://i260.photobucket.com/albums/...besin-situ.jpg
GM 5L40-E


https://i260.photobucket.com/albums/...umptubeout.jpg
ZF 6HP26


https://i260.photobucket.com/albums/...psksrofkuv.jpg
ZF 5HP24


Phil

Hey RRPhil,


I am not sure where I can get this tested in Chicago. I also do not have a garage so everything I do usually needs to be done in a day or so, so I do my best to fix things quickly.


I have noticed there are no seals at that location and I quickly researched and found out that is how it is supposed to be.


I will keep you all updated..


Thanks,


Ozzie

Hey RRPhil,


I am about to open up the valve body once again to replace the orifices and seals etc. (got the kit) and I would also like to do a vacuum test if possible. Do you have any resources for that process that you can share with me? Perhaps the vacuum test locations on the valve body?


Please let me know,


Thanks,


Ozzie

I’m curious which ‘kit’ you’re referring to. I’m not aware that Sonnax do a kit for the 5HP24. Do you mean the ZF 5HP24VBK valve body kit?

https://i260.photobucket.com/albums/...s26df0ae3.jpeg

I would certainly first check all valves for delamination of the anodised spool surfaces

https://i260.photobucket.com/albums/...psq1oj3hik.jpg

The two main wear areas are the main pressure valve and, to a lesser extent, the lubrication valve and Sonnax do an oversized replacement just for these two valves for the 5HP24.

https://i260.photobucket.com/albums/...ps12bfa809.jpg

https://i260.photobucket.com/albums/...ps0ff24a45.jpg

For the main pressure valve I would concentrate on the vacuum readings from these three worm tracks :

https://i260.photobucket.com/albums/...pshrbvpz2c.jpg

https://i260.photobucket.com/albums/...psb2843e75.jpg

I’d be interested to see the vacuum test result you get from the TransGo valve as I’m personally not convinced about its sealing capability

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

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

Phil

Hey RRPhil,


Yes, that is the kit I have and will be replacing everything in there including the wire harness I also purchased.



Thanks for all the great info once again.


I will let you know about the results for sure..


Cheers,


Ozzie

And finally an update after months :


I have been looking around to find another valve body to rebuild and found one from a junkyard. I have been getting many other parts from there for my X5 anyway. I also built my own vacuum testing device to be able to test things properly.


I rebuilt the valve body with the kit I had bought some time ago and vacuum tested the areas RRPhil showed me and everything looked good. I replaced the valve body with the one I had on the car and I still have the same issues. So it is obviously not the valve body at this point that causes the delayed engagement issues. Car still has no engagement issues sometimes (meaning it does not engage at all once in a while) but once it engages after several shifting up and down manually (1 to 4 then back to 1 usually helps) I can drive without any issues for the rest of the day which still makes me believe there is a pressure issue.


What else could be the problem? The fluid / filter combination can cause this? I have been using a Duralast filter (and Castrol Transmax import fluid) and I saw some people had problems with that filter or any other non-original one. Would an original Filtran filter make a big difference?



Also, is it possible to measure the pressure inside the transmission somehow?


I am aware that I may have to eventually look into rebuilding my transmission but until then I would like to eliminate every possible issue.


Need more feedback please..


Thanks,


Ozzie