Thread: More 5L40E problems

Well I can vouch for a bit better driving experience after having my TC lowered by 300 RPM, its not day and night but its noticeable.

Second rebuild done - sonnax kit, ZF kit, clutch packs, pump, the works, will see how long this one lasts.

Good to hear.

Mine is more than 300, I'm guessing something like 500. We have friends at Mt Nebo that we visit often, there is 17km of winding mountain road that has a 70 speed limit. At 55-70 in the hills is where the mod is really noticeable, with the 500nm retune and the TC mod it is just really nice - a different car. Windows down, roof open, o'yeah listen to that turbo whistle.

I figure it is a nice truck, we like it and it is our 2nd car so it doesn’t see many km during the week. We plan to hang on to it for a long time - happy to spend - ok, not happy but can justify the coin to make it right. Its a lot cheaper than changing cars...

Wife's car needs a mechatronics unit @59km - it is the valve body with ECU and sensors in one unit (ZF boxes are like this). No one in Aus is equipped to repair them so dealer only. - O'yeah, the independent trans shops can’t fit them because the ECU needs to be loaded with software, so it won’t work if they fit them – dealer only.

Makes GM5L40 repairs seem cheap. All the anti GM folk, wait till you need a ZF machatronics unit!!

I've got one coming from Denmark for 1/3 cost and will fit it myself, because under EU laws the dealer network is not allowed to monopolise the parts manufacturers, they can supply the unit preloaded with software because they have access to factory files.

Dealer wants $3900 to fit a new valve body, essentially because a valve has failed. It is still going to cost me 1200, but I get a stage 1 transmission tune preinstalled. What a crapper, both cars having trans issue.

Lads not sure but think my auto might need to be overhauled .if I keep it at 80 km an hours it feels like it going over a cattle grid but all other speeds no problem & I have had no issues with my auto only this any Ideas + if I get the auto rebuilt by Rhys it should not cost as much as if I wait for it to fail, any feedback would be appreciated.

hey Declan

Sounds like clutch vibration?

My first symptom (which I didn’t Identify at the time) was a harshness/ vibration @ 80km/h, TC locked, on a hill as I put the foot down - Lift off and it went away. Put in sport mode (TC lockup drops out) and it was fine.

Test for you.
While at 90-95 with TC locked, push the throttle down. You don’t want it to drop a gear, but give it as much as you can without kick down. If the clutch is slipping you will notice it at this point. If all is good the car should just go.

If the clutch is slipping it is eating itself away. The box has dropped pressure. It is not a TC clutch failure, the clutch is the symptom, and drop in clamping pressure is the problem - caused by wear in the pump housing, or the valve body, or the regulator valve, or or or. Rhys knows what needs doing.

If it is slipping, get it done NOW. Once all the clutch lining is gone it starts to eat metal plates and pump metal through the box – yeah more $. This is why everyone points at the TC clutch, because when the box is opened there’s metal everywhere, and the only thing that looks wrong is the eaten clutch in the TC. The filter will become blocked and you will loose drive as the valve block looses supply.

Yep, do what Harlie said - get it sorted now. Rhys has brand new valve bodies that are made of stronger stuff now than they used to be. This will fix the line pressure issues you're experiencing with the suffering clutch in your TC. Hopefully it's not too far gone, but Rhys will tell it to you straight - he won't tell you something needs doing if it doesn't.

If it fail completely you'll be up for much bigger dollars - the pump housing will need machining if it gets metal in it, and that is expensive.

there is a bit more to it than just the valve body.... get the pump done, regulator valve as a start.

Indeed, I didn't mean that as a complete fix, just that there is a good fix for the line pressure issues, and to get it looked at sooner rather than later.

Thanks all for the feedback can anyone give me Rys address so I will look at bringing the car up to get the auto done how long do you have too leave it with him to fix gearbox might make it a trip.