M1078 Transmission cooler

[timberrrrrr]

Been thinking it would be a good idea to replace the coolant / transmission fluid heat ex-changer out of my M1078 to an air cooled unit like in the M1088 and M1083's.

It seems the possibility of coolant eventually getting into the transmission via the heat ex-changer is a good reason to consider this.

Thoughts?

 

[snowtrac nome]

That likely wont happen if you were going to tow loads in high heat I might recommend it, but for cool climates it gets the oil up to operating temp faster.

 

[simp5782]

I recommend ditching the heat exchanger and going with solely air to air unless you are in a colder climate region. However you may check a thread by swamp donkey as he did a extra air to air cooler for his allison in his m923 and added bypass valves on the heat exchanger so he can use it in colder times to keep the transmission at temps but run the air to air with it's own fan. By using air to air the transmission never gets about 160 degrees. compared to around 200/210 with the heat exchanger. Allison's dont like heat very much especially if you are towing or running around with a camper like yours.

Helped a buddy ditch the heat exchanger in place of an air to air on a 1078A1 and now the fan clutch hardly ever comes on. It is amazing how much extra heat that transmission does put on the engine.

Every heat exchanger I have had fail on the 939 series trucks it has leaked out the end of the unit and not into the coolant.

 

[Suprman]

Got any pics of the air cooler installed?

 

[timberrrrrr]

I agree. With the camper on the back, I think air to air is the way to go.

Thoughts on where to get an air to air cooler?

 

[Third From Texas]

Thoughts on where to get an air to air cooler?

I start looking thru a list of HD RV and semi transmission coolers. There's no shortage of them out there and to my knowledge nothing that would make one specific to the Allison.

It's a pretty common add-on for tow packages, so should be lots of reviews available.

 

[timberrrrrr]

Thanks for the tip. A semi truck cooler would be good. Was hoping somebody might have a lead on a cooler from a M1088 or M1083

 

[scottmandu]

M1088 cooler is entirely different from a 1083, 1084, 1085... Stating this I have a cooler and fans from a 1088 I parted out.

 

[coachgeo]

Confused on air to air? you mean air to coolant or oil? found info on air to air.... for conditioning/converting "air" temps ... but not air to air .... for conditioning/converting temps of a liquid like tranny oil.

 

[scottmandu]

An air to air cooler would be the intercooler. The transmission coolers for the LMTV are liquid to liquid and the MTV has two coolers, the same cooler as the LMTV and an air to liquid cooler mounted rearward of the cab.

 

[coachgeo]

An air to air cooler would be the intercooler. The transmission coolers for the LMTV are liquid to liquid and the MTV has two coolers, the same cooler as the LMTV and an air to liquid cooler mounted rearward of the cab.

that is exactly how I picture and word it as well. This discussion speaking of "air to air" in reference to a tranny cooler makes no sense at all.

 

[Awesomeness]

By using air to air the transmission never gets about 160 degrees. compared to around 200/210 with the heat exchanger. Allison's dont like heat very much

My transmission doesn't seem to run it's best until it has thoroughly warmed up to 200°F (been at that temp for a little while, so all the parts have reached that, not just where the sensor is). I wouldn't want it to run cooler than that (e.g. 160°F).