While cruising through some interesting threads, I saw a brief mention of a ZF primary control valve upgrade which would supposedly address the common failure of the "A" drum in these transmissions. Did a search, but couldn't find any additional information.

I'm having the transmission serviced next week (oil and filter change) and, if this modification is worth it, I would have it done at that time. Can someone point me in the right direction on this?

Thanks!

 

I just sent a XJ8 member some info. Here is same:

http://jagrepair.com/images/AutoRepa...%20ZF5HP24.pdf

Main Pressure Valve 5HP24 - 5HP30

 

Thanks; just the information I was looking for. Any suggestions on where to get the main pressure valve and/or the lower valve body ($$$)?

 

224---look on the "Main Pressure Valve" pictured in the link above--given by 237 and you'll get your answer.

Chuck
05/XK8 Conv.

 

A couple of years ago someone recommended Sunbelt for valve body rebuild:

AW55-50, O1M, JF506E, 5R55e, 09G Valve Body Replacement

 

Thanks for the lead on Sunbelt. I called them, and I can get a rebuilt valve body for $ 450 (ouch) with the Sonnex pressure regulator upgrade installed. My transmission is getting serviced next week with OEM fluid, filter and pan, and I can have the mechanic swap out the valve body then. The transmission shifts perfectly now, so I may be wasting my money doing this (and I will never know for sure), but having read about $ 5,000 transmission rebuilds on this forum, I figure it's worth a shot.