Thread: TDI Auto transmission overheating

I know I will be in the minority here, but I don't believe the stock cooler set up is "marginal at best" as seems to be popularly thought. Certainly not with only 1200kg behind it, too. I often have far more than that on and I've never seen the light come on (it does work BTW too).

How many km on the box? I'd make sure the cooler is perfectly clean externally, give it a proper service, filter change and check the adjustment of the kickdown cable is correct. Use any of the lubricants listed here. ("A" list is synthetics - Transmax Z has good reports all round)

Originally Posted by B92 8NW

I know I will be in the minority here, but I don't believe the stock cooler set up is "marginal at best" as seems to be popularly thought. Certainly not with only 1200kg behind it, too. I often have far more than that on and I've never seen the light come on (it does work BTW too).

How many km on the box? I'd make sure the cooler is perfectly clean externally, give it a proper service, filter change and check the adjustment of the kickdown cable is correct. Use any of the lubricants listed here. ("A" list is synthetics - Transmax Z has good reports all round)

Thanks B92,
The transmission fluid and filter screen was replaced at 74,000k and car now has 120,000k so fluid is probably due for renewal. I've also checked the cooler is clean from the outside and not restricted and it was ok. I'll change what fluid I can by draining the sump, i'll have to put Dexron in rather than synthetic as I don't think you can mix and I can't get all the fluid out of the torque converter etc.
Cheers
Mark

Mark I am not certain a bigger cooler will help in this case, as I think you may actually have a trans problem. Get it checked for line pressure, it sounds as if it is slipping excessively. 1200Kg is nothing to one of these boxes unless you were trying to tow it in deep sand

JC

My warning light came on when towing a 1700kg caravan up a pass in Scotland called "Rest and be thankful"

I was told by several mechanics that the best thing to do was to manually change the gearbox down into 3,2 or 1 as needed rather than allowing it to try and lock overdrive in D.

By leaving in D and running at speeds slowing that the lockout speed of approx 49mph it keeps pumping trying to get into the higher gear or overdrive.

It works for me as i have been over some steep and long passes in Europe, in hot conditions, since with the van on the back and no warning light

What sort of hill are you talking about? I've had a similar problem towing an Avan, similar weight, out of Gloucester. To Barrington Tops & Thunderbolts Way to Nowendoc. Both about 1000m. After the first time & because I had other issues I had the box overhauled. I always change manually when towing & the second time the light came on I was already in 1st. I dropped down to low range & within a minute or so the light went off. I would have thought this box could handle anything a 300 TDi could give it. Both times the weather was warm not hot. It is possible one of the thermo fans was not working at the time.
I was interested to read this thread & would like to hear other peoples experiences.
Michael.

Originally Posted by Mikems

What sort of hill are you talking about? I've had a similar problem towing an Avan, similar weight, out of Gloucester. To Barrington Tops & Thunderbolts Way to Nowendoc. Both about 1000m. After the first time & because I had other issues I had the box overhauled. I always change manually when towing & the second time the light came on I was already in 1st. I dropped down to low range & within a minute or so the light went off. I would have thought this box could handle anything a 300 TDi could give it. Both times the weather was warm not hot. It is possible one of the thermo fans was not working at the time.
I was interested to read this thread & would like to hear other peoples experiences.
Michael.

Thanks Michael
It would be around 600m from Richmond to Bilpin which is the section the light came on. I also went into low range to achieve lock up where the clutches are not working so hard and the light went off (also works when beach driving). I am not sure if having it locked in first or second rather than D makes any difference but would doubt it. Did you notice any improvement after the rebulid? does the light still come on on the big hills?
Also the cooling fans only come on when the A/C is on so I'm thinking of wiring a relay in so I can switch them on independently, I don't think they do a great deal for the transmission cooler anyway as they are behind and there is not much air flow around the trannie cooler when I've had the grill off to check them out.
Cheers
Mark

Hi Mark have a look at this old thread of mine

http://www.aulro.com/afvb/discovery-...placement.html

As metioned in the thread it turned out the original transcooler was blocked. By the way a lot of the heat you feel around the shifter comes from the light bulbs that illuminate the shifter, they are on all the time the car is running.

Adrian

Mark, I have been up Kurrajong with the van & had no trouble. I just read Adrian's thread & the last suggestion about the lines running close to the exhaust makes sense. When climbing like that the EGT is up in the high 600s. Shielding makes sense. The last time the light came on I also had trouble with the starter motor which operates fine under normal conditions.
Michael.