Diesel transmission temperatures

[Hunno]

I'm sure you are already aware never tow in overdrive.
With the earlier GC tow in 4th Gear (5 Speed).
6th Gear (8 Speed).

[SouthernComfort]

Originally Posted by Cruise Control

Vehicle usually carries 2 and is relatively unladen, GVM including towball mass not a problem.

Trailer is rated to 3.5 tonne but load is 3.2 tonne fully fuelled (300 litres) so there is leeway here.

You are saying that transmission temperature is one way if telling that I am asking a lot of the vehicle, although if I recall my specs correctly it is rated to pull 3.5T with a GCM of 6.5T

Therefore do you believe that 101c is too hot ? If so, what do you believe is acceptable ?

On the occasional hill probably not, so long as it drops back and isn't prolonged at that temp. The 8sp box apparently does run hotter than the 5sp which rarely gets above mid 90's towing on big hills in the heat. I also tow at around 90kph max.

Sorry to labour the weights thing, but I'm confused as to what you mean by "3.2t fully fueled". Fuel weight belongs to the car (GVM), as does ball download. Do you mean the trailer ATM is 3.2t?
The ratings on my 2013 are GVM 2949kg, Trailer ATM 3500kg, GCM 6449kg.

[Cruise Control]

Sorry, it's a trailer boat. 😃

[desertman]

Originally Posted by Hunno

I'm sure you are already aware never tow in overdrive.
With the earlier GC tow in 4th Gear (5 Speed).
6th Gear (8 Speed).

Hunno,

Why and what is the theory behind not towing in overdrive?

Cheers,

DM

[Treebreakerbob]

Originally Posted by desertman

Hunno,

Why and what is the theory behind not towing in overdrive?

Cheers,

DM

With the 5 speed it only locks the TC in fifth and the gearbox runs around 80 deg, if you tow in 4th the temp goes up as the TC slips constantly. Due to this my vehicle pulls nearly as hard in fifth as fourth. There is no layshafts in autos and the 5 speed models are at 2,000 rpm for 100 kph in fifth so if your rig is good for 95 - 100 kph fifth is my choice

Bob

[Troutman]

My 2015 diesel trans temp gets up to around 82C but it takes nearly an hour belting around the hills to get there. The same run with my 4.1m boat on the back might see 92C.

[Cruise Control]

Originally Posted by GMEMUD

I tow a 3.3t caravan at legal limits on highways and trans temp will sit in high nineties if pushing into headwind, slight inclines etc. It will get over 100 on bigger hills, will always come back to 92 on declines or tailwinds on flat.

Are you an 8 speed and if so, what gear do you tow in ?

Cheers