Thread: Additional Transmission Oil Cooler for a D4

When mine is driven in manual mode the torque converter stays locked for 4th, 5th and 6th which would reduce heat generation compared with auto mode. In auto mode it wants to hang onto the gears longer when a trailer is attached, once again reducing torque converter slip and heat generation.

HI Georgek.TryDavis Performance landy's. Annangrove. Syd.He seems tuned in!!

Originally Posted by GeorgeK

.....I have been told that an additional transmission oil cooler should be fitted to cool the transmission oil. ..... by a reputable third party.

Don't attach a damn thing to the the ZF pipework or your
warranty for the vehicle will be toast !
A fan-blowing-on-pipes is the only chance you should take ;
like extra Kens on RRC rads , back in their day .
PS. Reputable has got nothing to do with it !

Can you define "reasonably heavy" and "around the block"? The D4 has a built-in tx cooler that's fine for most applications and climates. I tow a 2.7T van without issue.

Cheers,

Gordon

Originally Posted by gghaggis

Can you define "reasonably heavy" and "around the block"? The D4 has a built-in tx cooler that's fine for most applications and climates. I tow a 2.7T van without issue.

Cheers,

Gordon

Agreed.. The D3/D4 seem to have a better cooling system on the trans AND a better control system for preventing unnecessary heat build up in the box.

I've towed the 2.3T boat without issues and it wasnt exactly cool that day

Or change the ATF regularly say every 25,000 km?

Hi Gordon,

Sorry I should have been more specific. 'Reasonably heavy' means an ATM of around 2.9 tonne hopefully not greater. 'Around the block' means around Australia. The intention is to live in the van and tour, part-time work permitting, for the next few years. The daily towing range is planned for about 200-250km/day when towing in all conditions. The general plan is to arrive at a destination, stay for a few days and set up in a caravan park or similar and then move on. If I'm 'free camping' then we will be moving daily.
A very experienced D3 owner, in a similar situation to me i.e. being permanently on the road with a caravan recommend the fitting of an additional transmission oil cooler. I just don't know if the D4 transmission cooling situation has changed from the D3 and whether an additional cooler is now needed.

Thanks

George