Diesel transmission temperatures
 

Hi Guys

I have a 3 litre diesel WK2 Overland.

My normal transmission temperature just running around is 91degrees C, when towing a heavy load I will get up to 101 degrees C. The transmission does not hunt but will kick back a gear when running up slight inclines. I tow at 100 KPH pulling 3.5 tonnes

Is this normal or high? I am getting messages from other non jeep,drivers that this is too high and will ultimately cause transmission failure - any feedback will be appreciated.

Cheers

year and what speed transmission.?That temp would not be too much of a problem if for short periods.However continual high trans temps does kill ATF fluid.How old is the fluid ,if towing full time change around every 30000klms.
There is much info on towing for both 5 speed and 8 speed WK2s on this AJOR site suffice to say there are a number of differing views also !!.eg best gear to tow in ,speed etc. Another obvious question are your cooling fans operating at this temp.

If you're pulling a full 3.5t at 100kph you're asking a lot from the car and IMO trans temp is one way of telling you that.

Forgive me for saying, but these numbers are potentially scary in other ways e.g. are you operating within your GCM and GVM weights? Towing 3.5t gives you hardly anything left for payload in the car after taking into account passengers and ball download mass.

2014 8 speed. Tow this weight maybe 8 times a year, usual distance is less than 100 kms one way. Once a year tow 1,300 one way trips are usually across relatively flat terrain with only a few slow hills here and there.

When you say that temperature would not be too much if a problem for short periods, I take it you are talking about the 101 c ?

If 91c is the normal transmission temperature what would you think is an acceptable increase under load .

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 ?

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.

From the info I have on the 2014 GC diesel the coolant thermostat is fully open at 225F or 107c .This year model GC runs quite a bit hotter than earlier models eg the 2012 GC diesel.. As far as the ATF temps ,anything over 107c constantly will start to degrade the ATF and shorten its life.
There are many other things that can come into play causing high ATF temps .Age of ATF and klms done. Dont believe the old sealed for life argument.!! Life of ATF as temps go up.
90c----80000klms
100c----40000klms
113c----20000klms