Thread: Extra gearbox oil cooler for towing Y or N ?

Originally Posted by Narangga

Just so that you are aware, as Bulletman says above - it is a replacement not an additional.

Probably too early yet, but do you have any design, anecdotal or other info which suggests this might improve ATF cooling (and hopefully not increase coolant or engine oil temps)?

Originally Posted by gavinwibrow

Probably too early yet, but do you have any design, anecdotal or other info which suggests this might improve ATF cooling (and hopefully not increase coolant or engine oil temps)?

It’s external to the radiator, in direct airflow.
It will definitely cool more effectively than a tube in tank cooler.

Even the smaller unit would do a more effective job.

Originally Posted by gavinwibrow

Probably too early yet, but do you have any design, anecdotal or other info which suggests this might improve ATF cooling (and hopefully not increase coolant or engine oil temps)?

When my mechanic installed the refurbished transmission he suggested the new cooler. I was happy to go that way as I thought it would offer better transmission cooling from the new cooler and better cooling efficiency for the radiator without it having to deal with the transmission, even with the transmission cooler mounted in front of it. Time will tell if my $1K was well spent or wasted.

Originally Posted by Narangga

When my mechanic installed the refurbished transmission he suggested the new cooler. I was happy to go that way as I thought it would offer better transmission cooling from the new cooler and better cooling efficiency for the radiator without it having to deal with the transmission, even with the transmission cooler mounted in front of it. Time will tell if my $1K was well spent or wasted.

I don’t think you’ll find any negatives.

Following this with some interest.

Have not had any cooling or transmission issues, but watching temps yesterday via the RVCIQ on the drive home from Albany, oil temp 126 deg C, coolant temp 99-106 deg C, towing ~1750kg camper trailer uphill at 99-100kmh road speed (cruise set at 106kmh) with 35 deg ambient. Car behaved perfectly well.

Originally Posted by Eric SDV6SE

Following this with some interest.

Have not had any cooling or transmission issues, but watching temps yesterday via the RVCIQ on the drive home from Albany, oil temp 126 deg C, coolant temp 99-106 deg C, towing ~1750kg camper trailer uphill at 99-100kmh road speed (cruise set at 106kmh) with 35 deg ambient. Car behaved perfectly well.

Just confirming - transmission oil at 126 degC?

If so then this is far too high. You want it to stay between 80-90 degC for optimum transmission and oil life.

Originally Posted by DiscoDB

Just confirming - transmission oil at 126 degC?

If so then this is far too high. You want it to stay between 80-90 degC for optimum transmission and oil life.

Oops, no, engine oil temp. Could not see the trans oil temp on the RVCIQ in the dials i had selected.

Originally Posted by Eric SDV6SE

Oops, no, engine oil temp. Could not see the trans oil temp on the RVCIQ in the dials i had selected.

My 2.7 is about the same. On a warm long trip towing, engine oil stabilises at around 20 degrees higher than coolant, and ATF a couple of degrees higher than coolant. Coolant normally around the 100 in these circumstances but can get to 104, and once up to 107 at which point I dropped a gear and was soon back to 104. Bearing in mind this is WA where we don't have too many steep grades.