TOW VEHICLE TRANS. TEMP.

[Ruune]

From Chevy's website


Std on all trim level Tahoe's Trailering equipment
includes seven-wire harness with independent fused trailering circuits mated to a seven-way sealed connector and trailer hitch platform with two-inch trailer receiver

Option on all trim level Tahoe's Trailering equipment, heavy-duty
includes transmission cooler and heavy-duty cooling (3.73 axle ratio only on 2WD; 3.73 and 4.10 axle ratio on 4x4)

From GMC's, no mention of aux cooler

Std on all trim level Yukon's Trailering equipment, heavy duty, includes trailer hitch platform, 7-wire harness with independent fused trailering circuits mated to a 7-way sealed connector, 2" trailering receiver, and electric brake controller jumper harness

EDIT: Aux cooler is listed as an option if you go through the "customize your Yukon"

I've got an '07 sierra Z71 4x4 w/ the heavy trailering package. It does have a separate trans and oil cooler. Additionally, it has a separately fused power circuit for the trailer wiring, a 7-wire harness, receiver hitch, eaton locking rear diff (3.73:1), and a larger air filter.

Also, there is no difference (powertrain-wise) between the Tahoe & Yukon and the Sierra & Silverado. Beneath the skin, they're the exact same thing. However, I've been told that the fit & finish on the GMCs is better than on the Chevrolet counterparts- the jury is still out on that though. I just like the front end on the Sierra more... Plus I got a deal on an '07.