Gearbox Problems Experts Please Help!!!

[QIK51X]

Hey guys,

I have a VR commodore Automatic V6. I'm having a problem with my gearbox that has my gearbox specialist with no idea whats going on. Hopefully there are some holden specialists on these forums who can help. Before I start I will tell you what mods I have done to the gearbox.

Gearbox was rebuilt 12 months ago, with stage 2 shift kit heavy duty clutches up the oil pressure etc.
Took my car for a service yesterday cause it was due and I told him a little problem I was having when the gearbox heats up after a long drive.

The problem is when im doing say 80kph in 3rd or 4th gear cruising and I go to overtake another car, I put my foot all the way down on the pedal and it doesn't want to downshift into a lower gear. It just stays in 3rd gear or 4th gear whichever it was in and just revs out slowly in that gear. It only happens sometimes on long drives, it usually works well. When it heats up it will take off in 2nd or 3rd from lights and not in 1st, even when i manually put it in 1st it will still take off in 2nd. There are no error codes coming up in the motor or the gearbox, nothing.

My gearbox mechanic hooked up the scanner and we went for a drive. He heated up the gearbox a bit and it started doing it so we went back to his shop. He fully serviced the gearbox, put the scanner back on went for another drive and it was still doing it. Went back to the shop he checked nearly everything including the valve body, changed the brain of the gearbox, tested all the solenoids checked the clutches everything is ok. went for a drive still doing it.

I was wondering if the memcal I got with my crow cams kit is making the gearbox play up or its something mechanical/electrical in the gearbox. Have any of you had a similar problem and found a way to fix. I know there are some very smart people here after reading a lot of the posts over the years.

Any help at all will be greatly appreciated. I just dont want to pay another $2000 for a new gearbox when this one is not slipping, its a strong gearbox, it still chirps gearchanges thats how tight the gearbox still is.

Once again any help will be appreciated. Sorry about the long post everyone.

 

[hako]

When the VS came out, they had problems with the oil overheating and solved (!) it by adding a oil to air cooler to run in series with the oil to water one in the radiator. Also they put a lock on the dipstick to stop it ejecting when the fluid boiled (ain't they intelligent!!!). The VS had the 4L60E box which has its own ECU whilst your VR uses the engines ECU (I think)
You have a VR which has a very similar auto (except for electrics) so maybe your mods are causing to oil to heat up just that bit more where it affects its performance. So, cheapest quickest option would have to be to fit the largest oil to air cooler available. I've seen people use aircon condensors for this purpose as they are large,well built and a dime a dozen. You can use car or house aircons for the condensers. That could keep your trans oil below the heat threshold at which it plays up. Also know that some cars benefit from the use of synthetic trans oils which do not alter their characteristics like dino oil...especially some exotic imports.
BTW...long posts that cover all angles have the best chance of a proper answer (not that mine is a proper answer).

 

[QIK51X]

When the VS came out, they had problems with the oil overheating and solved (!) it by adding a oil to air cooler to run in series with the oil to water one in the radiator. Also they put a lock on the dipstick to stop it ejecting when the fluid boiled (ain't they intelligent!!!). The VS had the 4L60E box which has its own ECU whilst your VR uses the engines ECU (I think)
You have a VR which has a very similar auto (except for electrics) so maybe your mods are causing to oil to heat up just that bit more where it affects its performance. So, cheapest quickest option would have to be to fit the largest oil to air cooler available. I've seen people use aircon condensors for this purpose as they are large,well built and a dime a dozen. You can use car or house aircons for the condensers. That could keep your trans oil below the heat threshold at which it plays up. Also know that some cars benefit from the use of synthetic trans oils which do not alter their characteristics like dino oil...especially some exotic imports.
BTW...long posts that cover all angles have the best chance of a proper answer (not that mine is a proper answer).

Thanks for your long answer champ. This is what I was suspecting but wasn't sure I asked my gearbox mechanic and he goes it won"t be that its more than likely a ecu problem. I reckon you are right he is wrong I'll tell him to have a proper look at it. Thanks again.

 

[Immortality]

i know it's a long shot but possibly try running the car with the original memcal if you still have it and see if it plays up. as said above, the fitting of an extra trans cooler really is mandatory when upgrading your auto box as the factory fitted jobby in the radiator is marginal at best and cetainly not up to the job when a car is driven spiritedly often as probably thecase for anybody who has taken the time to fit a trans shift kit like yourself

 

[QIK51X]

i know it's a long shot but possibly try running the car with the original memcal if you still have it and see if it plays up. as said above, the fitting of an extra trans cooler really is mandatory when upgrading your auto box as the factory fitted jobby in the radiator is marginal at best and cetainly not up to the job when a car is driven spiritedly often as probably thecase for anybody who has taken the time to fit a trans shift kit like yourself

The problem is the memcal which comes with my crow cams kit I installed on the car is the only memcal that works on my car. Before the crow cams memcal I had a memcal made up by Dicks Electronics and this memcal won't let me turn my car on whatsover, so I can't change it over. The bad thing is before the service yesterday the gearbox was only paying up once every few weeks now after they did the service it does it everyday. They have made it worse. What brand of cooler should I purchase, I don't care about price I just want it fixed asap?

Its very annoying and dangerous when your at intersections you find a gap in the traffic thinking you can accelerate quickly to make it, and you realise your car is taking off in 2nd or 3rd gear and it doesnt accelerate at all. Thank god I have 3.91 diff ratio as if I still had the 3.08's it will be worst still, and the cam doesnt help with low down power either.

Thanks for your reply. Appreciate it.

 

[dmitch]

pwr make a good trans oil cooler www.pwr.com.au

 

[hako]

This mob is in Melbourne and carry heavy duty ones that blokes fit to 4WDs to tow caravans. But as you say its getting worse it does seem to point to the memcal as well. Either way you will still need an oil cooler.
http://www.automatictransmission.com.au/release.asp?NewsId=12319