Trans cooler

[97audia4]

I have decided on the true cool 40k trans cooler, and I will be towing a 7x16 with extra height dual axle trailer that will be carrying 2 race bikes, camper gear, grilling supplies and tools. Estimated weight will be from 4800 to 5600 at the heaviest. I already ordered a WD hitch with active sway control.

The factory 09 Yukon Denali cooler is small and towing up and down hills from central NY and through the hills to NC from central PA I want to make sure the trans stays cool. May need to add a thermal bypass in the winter as it can get to well into the 20's here but I cannot find the min operating temp for the 6l80e anywhere.

I found these pictures from EAD performance, they sell the bracket but I can fab those on my own. What I am interested in is since the factory cooler lines are run from the bottom up to feed the cooler can the true cool be run the same way as pictured?

I have read some controversy on this stating it should be mounted with ports on the top or it wont fill the cooler completely but I come from the class 8 world and mounting like this is perfectly acceptable.

 

[Rocket Man]

They can be mounted either way. Most of us mount them with the fittings on the bottom because that’s where the stock lines are routed to. I actually contacted Tru Cool and they verified it’s fine with the fittings on the bottom. Mine is working fine like that.

 

[97audia4]

They can be mounted either way. Most of us mount them with the fittings on the bottom because that’s where the stock lines are routed to. I actually contacted Tru Cool and they verified it’s fine with the fittings on the bottom. Mine is working fine like that.

Thanks, do you happen to know the part number for the fittings that accept the OEM Gm lines for the cooler? I also am going to pick up a 5/16th compression fitting and just cutting the oem line and turning it 180 to fit the new cooler.

 

[swathdiver]

The factory 09 Yukon Denali cooler is small and towing up and down hills from central NY and through the hills to NC from central PA I want to make sure the trans stays cool. May need to add a thermal bypass in the winter as it can get to well into the 20's here but I cannot find the min operating temp for the 6l80e anywhere.

See post #290 in this thread:

https://www.tahoeyukonforum.com/threads/useless-information.97483/page-29

The later K2s added a thermostat to the 6L80 that opens at around 190 degrees.

 

[Rocket Man]

Thanks, do you happen to know the part number for the fittings that accept the OEM Gm lines for the cooler? I also am going to pick up a 5/16th compression fitting and just cutting the oem line and turning it 180 to fit the new cooler.

I don’t. I used the included rubber lines. I keep meaning to run braided lines with AN fittings to the trans but haven’t yet.

 

[97audia4]

shop manual says trailer towing should occur in D4

See post #290 in this thread:

https://www.tahoeyukonforum.com/threads/useless-information.97483/page-29

The later K2s added a thermostat to the 6L80 that opens at around 190 degrees.

Thank you for the info, as for towing in D4 is that tow mode or just in drive with trailer hook upped?

 

[swathdiver]

Thank you for the info, as for towing in D4 is that tow mode or just in drive with trailer hook upped?

My pleasure sir! Either, Tow/Haul is really only effective when at 75% or more of the GCWR or about 10,500 pounds.

 

[Doubeleive]

it's easier to mount it with the lines coming in from the top, facing them down makes for a very tight fit and didn't want mine to get pinched, I used some 1" standoff's so it wouldn't rub on anything, drilled 2 holes in the upper radiator support for mounting and the existing holes on the bottom worked perfect then I just cut the included brackets so it fit just right, regardless you can mount it in any position the transmission fluid pump will push the fluid thru, the point of course is airflow. also you will want to move the ambient temperature sensor to the side of the cooler otherwise it will read the outside air temp from behind the cooler mine kept saying it was 120deg outside when it was really 80deg

 

[Doubeleive]

this is how mine turned out, the photo's above are not from a NNBS there from either a nbs or a Silverado, the space to put it on the nnbs is smaller.

 

[97audia4]

My pleasure sir! Either, Tow/Haul is really only effective when at 75% or more of the GCWR or about 10,500 pounds.

Ok so makes sense to use tow haul mode when towing the enclosed closed loaded at 5k punds and keep it in drive when towing my single open trailer weighing in at 2100 Max loaded.