Additional Transmission Oil Cooler for a D4

[GeorgeK]

Guys,

I am about to take delivery of a new D4...yay! Besides being my daily drive from next year it will be used to tow a reasonably heavy caravan around the block. I have been told that an additional transmission oil cooler should be fitted to cool the transmission oil. The transmission may get overly hot under heavy load. I would be grateful for advice concerning:
1. Do I need the additional cooler as suggested? My new van will be heavy;
2. Any suggestions as to type;
3. Does the transmission oil cooler need to be fitted by LR? and
4. Will my warranty be void if I have it fitted by a reputable third party.

Cheers

George

[Graeme]

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.

[Rostbiff]

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

[Neil P]

.....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 !

[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

[Tombie]

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

[CaverD3]

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

[GeorgeK]

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

[TDV6]

G'day George,

Don't jeopardize your warranty, I don't believe an additional tx cooler is required for the D3/4.

We towed a three ton off-road van around the island plus other trips approx 70k in all and had the auto fluid and pan changed at130k. On inspection the oil wasn't toasted but just slightly yellow.

The car has improved since the oil was changed.

HTH,

Ryall