Zf 5hp24 transmission issue

[Themoog]

Alright peeps.
Nearly 3 years ago the transmission on my 01 V8 lost drive so I had it rebuilt by a specialist at a cost of £2000..
All OK apart from a few months ago and again today it would not shift up past 2nd gear in auto mode. OK in manual mode. The first time I didn't think much of it as it was a very short journey down the road to my house. Today I drove it for a mile to a train station then switched off. Upon the restart it worked OK. Drove for 5 miles no problem and I'm currently sitting in it waiting for someone so when I restart and drive off I'll see if it's OK still.
What could cause this? Both times it was from a cold start and it's only done it twice.
Sticky solenoid maybe.. The fluid should be OK as it was refurbished. Ideas?

[aureliusmax]

Originally Posted by Themoog

Alright peeps.
Nearly 3 years ago the transmission on my 01 V8 lost drive so I had it rebuilt by a specialist at a cost of £2000..
All OK apart from a few months ago and again today it would not shift up past 2nd gear in auto mode. OK in manual mode. The first time I didn't think much of it as it was a very short journey down the road to my house. Today I drove it for a mile to a train station then switched off. Upon the restart it worked OK. Drove for 5 miles no problem and I'm currently sitting in it waiting for someone so when I restart and drive off I'll see if it's OK still.
What could cause this? Both times it was from a cold start and it's only done it twice.
Sticky solenoid maybe.. The fluid should be OK as it was refurbished. Ideas?

should you not call back the specialist and ask ? i got no ideas

[Themoog]

Could do but I thought I’d ask globally first to get some ideas

[X5chemist]

Scan it for codes first. Second, take it for a fluid level check.

[RRPhil]

The most common reason for a 5HP24 holding onto the lower gears is that the fluid is overheating. This is because the controller inhibits upshifts to ensure that the engine revs (and therefore the oil pump speed) stay high, to maximise cooling flow. The condition may be real (because the cooler is blocked) or false (because the temperature sensor is giving a spurious reading).

If this isn’t the issue, it could possibly be because there’s a problem with 3rd gear e.g. a problem with the D-brake.

If you have some diagnostic kit that can read off live values for the fluid temperature, this would probably be your best bet. Alternatively, you can test the sensor reading between pins 13 & 14 at the 16-pin connector on the casing:







or between pins 12 & 22 at the ECU:







Phil

[Themoog]

Hmm interesting. I do have C110 diagnostic tool that can tell me trans temp. I’ll check as both times it’s happened from a cold start. Thanks for that.

[Homerlovesbeer]

Great post RRPhil!

It’s friendly concise and accurate information from members that makes this forum so great!

[Themoog]

Agreed ��