Thread: Gearbox Cooling - Defender

I noticed heating when I was using CDL and low range for a long time continuously. After changing driving style and getting know car limitations I apply CDL only in real critical situations.

Ruslan

Does it not have an oil cooler on it?

R380 has provision for fitment of an oil cooler. I know the 130's have them fitted.

I'm pretty sure the D2 R380 also runs a cooler.

Are you sure its not engine/exhaust heat?

Ive seen a somewhat dodgy improvisation done on a series transmission..

a pair of tpieces were plumbed onto the filler and drain plugs one side was fitted with bungs and the other side went to an oil cooler plumbed under the tray at the rear above the popshaft.

Depending on how much cooling you want it might be enough

I've had a similar symptom (hot under seat boxes esp drivers side) in the past on long runs but not always. A mechanically minded mate got underneath and felt around and decided that it was like the handbrake was rubbing. We tested the brake, it was working, we released it, it rolled easy but it was very hot there. We even got under his Defender that had been following and his was cool as a cucumber.

Being as we were, out in bloody whoop whoop there was not much to do but keep going and keep an eye on it. Anyway the problem disappeared the next day. On this years trip it re-occurred, once. I though hmm here it is again. Next day gone.

Now it MAY have been because on the gravel shaly track I had diff lock on and my mate didn't but I don't think I did have diff lock on at that time. Next time it happens and I have the CDL on I'll take it off.

Originally Posted by D110V8D

Does it not have an oil cooler on it?

R380 has provision for fitment of an oil cooler. I know the 130's have them fitted.

Ummm, not all 130's have them fitted. Later model Tdi 130's don't, but all the Td5's I've looked at seem to have them.

Whoops!

As usual my technical knowledge sucks ass!

I'd be surprised if the gearbox was the source of the heat, although it will generate a bit, but it would be pretty minimal compared to the heat from the engine and exhaust , all of which flows back under the vehicle pushed by both fan and forward motion. Of course, a dragging handbrake will make a bit of an impression as well. I cannot see how diff lock in or out would make much difference, and if it did, the locked diff would generate less heat as there is a set of gears not working under load.
John