Auto Transmission - Any ideas

[Sancho]

Merry Christmas all. I have a little problem. I'm driving down to the French Alps tomorrow and have noticed (during my festive journeys) that my gearbox is playing up. Basically, it just keeps on revving without going into overdrive - it does 4000rpm at 70. Then, randomly, it finally does change up, without me accelerating any more or anything. Then, occasionally, it drops back down for a bit, then back up.

I've looked for a pattern and it seems to be temperature related. It just won't change up when cold, changes once it starts getting warm, drops when cruising and the temperature levels out, then goes back up when it's warm again. Any ideas? I've checked the ATF and that looks fine. I suppose I can live with it, but I hate weirdness (especially with a 1,400 mile round trip ahead). Maybe just leave the battery disconnected for a bit to reset the ECU? Anyone got a scientific answer? Obviously, I can't have any proper work done on it before tomorrow so also please shout if the answer is DO NOT DRIVE IT. It seems fine in other respects.

[AndyLala]

When was the last time you flushed the gearbox?
IE. remove the sump and clean out the filter...?

Mine used to do that when I first got it... and I took it to a Auto box specialist in Alperton who agreed to do it for £70.00.... I jumped at it... and it has changed nicely without that hunting ever since... two years now...

[Sancho]

Um.......Never. Had a look around some other threads and seems reasonably common so hopefully all is well.

[Apache]

Um.......Never. Had a look around some other threads and seems reasonably common so hopefully all is well.

Mine does that too, but seems to be the other way round. OK when cold, but after about half an hour it's fairly random when it goes into overdrive, and when it drops out. Can be anything up to 65-70mph.

I figure the ATF is a bit buggered (I've had the overtemp light on a few times when driving hard on slippy / steep ground) and hope changing it improves matters.

[BUSHWHACKER]

I figure the ATF is a bit buggered (I've had the overtemp light on a few times when driving hard on slippy / steep ground) and hope changing it improves matters.

Ya think??

[Apache]

Ya think??

Reminds me, I need some 5/8ths BSP to plain pipe fittings for my cooler so I can fit that when I do the ATF. eBay here I come!

[Bobafet]

Merry Christmas all. I have a little problem. I'm driving down to the French Alps tomorrow and have noticed (during my festive journeys) that my gearbox is playing up. Basically, it just keeps on revving without going into overdrive - it does 4000rpm at 70. Then, randomly, it finally does change up, without me accelerating any more or anything. Then, occasionally, it drops back down for a bit, then back up.

I've looked for a pattern and it seems to be temperature related. It just won't change up when cold, changes once it starts getting warm, drops when cruising and the temperature levels out, then goes back up when it's warm again. Any ideas? I've checked the ATF and that looks fine. I suppose I can live with it, but I hate weirdness (especially with a 1,400 mile round trip ahead). Maybe just leave the battery disconnected for a bit to reset the ECU? Anyone got a scientific answer? Obviously, I can't have any proper work done on it before tomorrow so also please shout if the answer is DO NOT DRIVE IT. It seems fine in other respects.

Had the same problem with an old volvo 240 GLT. I thought it was the ECU or low fluid but after much examination I traced it to a relay behind the dash that kept swithcing itself on and off and eventually off all together as the relay gave up!! I put new relay in and no more problems.....................m aybe the surf has a similar system?