02' 4.6is Supercharged / 107k / Trans. Fail. Safe

[oldskool racer]

Had a similar issue, cant recall the codes, but the solution was simply replacing the harness in the transmission. Something about a thermostat/temp sensor that failed. Maybe you will get as lucky, but after a new filter, fluid, and the harness, all was great

[740ilDuke]

Originally Posted by oldskool racer

Had a similar issue, cant recall the codes, but the solution was simply replacing the harness in the transmission. Something about a thermostat/temp sensor that failed. Maybe you will get as lucky, but after a new filter, fluid, and the harness, all was great

What made you decide to replace the harness? Codes? Hmm.

[RRPhil]

Originally Posted by 740ilDuke

....The 4.4 X5 box will work without issue, the only differences being the TC and Valve body....

Important to remember that the 4.6is model also has an additional friction & steel plate in the D brake to handle the extra torque. You can’t just swap the bellhousing/torque converter and the upper valve block assembly over to the 4.4i transmission.

Phil

[740ilDuke]

I think im going to have a guy locally rebuild it, got quoted at $900. Ill have it pulled and deliver it to him. Found a shop online that will reman the L51 TC for $250.

Hopefully the valve body is ok. $599 for that to be reworked.

[Dblock2151]

Good luck, let us know how it works out for you!

[bcredliner]

Unless you are sure what the problem is, since a transmission shop is pulling the transmission, I would have them do a diagnosis before they pull it and you start buying parts.

[RRPhil]

If the mileage is high it may be worth getting a Sonnax main pressure valve fitted. Worth doing a vacuum test first, but I find that I need to replace quite a few.







https://www.youtube.com/watch?v=54gBRA_yMnM

https://www.youtube.com/watch?v=jm_M4hk1YHI

https://www.youtube.com/watch?v=MZH3BkKlNfM



Unlike the 6-speeds, the solenoids on the 5HP24 are generally very reliable



Based on your symptoms, it’s also worth checking that your upper valve block doesn’t have a crack in the SV-1/KV-F circuit





Phil

[740ilDuke]

Wow, thanks Phil. That's a ton of information.

The X5 has 107k miles on it. It shifts perfect until it
gets warm and then loses it's mind. Upper gears seem fine, so
when I drive it (hardly never until this is fixed) I start in M-3 and
drive easy until up to speed and shift into M4 & M5.

Im not a transmission expert by any stretch, but appreciate the insight
and knowledge you've shared.

Here's the shop that's rebuilt a VB for me in the past.
https://revmaxconverters.com/product...ed-valve-body/

A gentleman about 90 miles away will rebuild the transmission for $900
& a shop in Chicago is charging $250 to reman the L51. VB another $600.

I'd considered a flush, but would rather just rebuild it instead of some now and some later. One shot and check all the boxes is what Im after.

What fluid is recommended?

Originally Posted by RRPhil

If the mileage is high it may be worth getting a Sonnax main pressure valve fitted. Worth doing a vacuum test first, but I find that I need to replace quite a few.







https://www.youtube.com/watch?v=54gBRA_yMnM

https://www.youtube.com/watch?v=jm_M4hk1YHI

https://www.youtube.com/watch?v=MZH3BkKlNfM



Unlike the 6-speeds, the solenoids on the 5HP24 are generally very reliable



Based on your symptoms, it’s also worth checking that your upper valve block doesn’t have a crack in the SV-1/KV-F circuit





Phil

[RRPhil]

Originally Posted by 740ilDuke

What fluid is recommended?

Only ever use either ZF Lifeguard Fluid 5, Pentosin ATF 1 or Mobil ATF LT71141 in your 5HP24. This guarantees that you have the right friction modifier pack to ensure that the torque converter lock-up clutch functions correctly in its ‘controlled slip’ mode





Phil

[oldskool racer]

Yeah, something about the code. I was trying to track down the codes it threw to help out, but cant find my notes. My mechanic recommended to try the harness before doing anything else, and it solved the issue! I know there are many folks on this board that are way savvier than I, just slanted to drop what worked in my instance.