External oil cooler for AW70-transmission in a 240?

From a point at sea, to the circles of your mind, this is Vestman:

Why do you think you need one? Do you do a lot of towing, do you have overheating problems, or is it just time for a new radiator?

I've got an external oil cooler on my 740. I don't particularly need one, but the internal one apparently developed a leak (in fact it was a false alarm) and I happened to have one lying around. It's just an aftermarket oil cooler bought from an accessory shop, about 5 inches x

9 inches. It's connected by a couple of rubber hoses and screw cliped to the oil lines, and mounted in front of the radiator with zip-ties. I guess this is way over-specified, because the one in the radiator is only a small cylinder about 1.5 inches in dia. and 6 inches long.

Someone on here mentioned that it might lead to over-cooling in the winter, but so far I haven't noticed any problems. But maybe your Danish winters are colder than our British ones.

Given that a leak in the internal cooler could quickly lead to failure of the gearbox, I reckon on balance an external cooler is not a bad idea.

"Stewart Hargrave":>

I have experienced that the tranny-oil have overheated twice (meduim brown colour), and that by medium quick highway driving after only about 40-70 miles. After that I changed the oil of course, but it happened again... I think the tranny is a bit sick or worn eventhough it has "only" 151k miles worth of wear. It also shifts a bit roughly between 2nd and 3rd when pushed a little. Oil level has always been correct.

Yep, but I've changed the cooler between the incidents, so I reckon that the cooler is of no guilt what so ever.

Oh well, it usually gets down to 5 or 10 degrees of frost. I don't think that will become an issue.

I just wanna extend the life of it instead of spending 2-300 £ too soon on an exchange unit.

Rgds, Lars Vestman, Denmark

The difference in cooling apacity may be hard to judge based on physiscal size. Air cooling stuff requires about 100 X more air flow than cooling water flow, and much bigger surface areas too.

From a point at sea, to the circles of your mind, this is snipped-for-privacy@ultranet.com:

This is true, but don't forget that the temperature difference between oil and air is much greater than oil and water in a warmed up engine.