Whats the best way?? (trans cooler)

**jbamonte** · 01-10-2016

I have run 2 Long/Dana Double stack 18,000 GVW trans coolers outside of the radiator in my 01 GP since 90,000 miles and the car now has 180,xxx miles on it. The 4T65E runs normally very hot and the reason for the 36,000 GVW coolers (and the reason that many tranny failures occur in these trannys with low miles on them (and failure to changes the fluid/filter often). The only issue in VERY cold weather (below 20 degrees) is that the trans takes longer than normal (running through the radiator) to shift into overdrive (trans fluid has to be 88 degrees). I just take it easy for the first 5 miles or so in very cold weather....I drive the GP year round in New England weather. The Long coolers have temperature control built into their design, not allowing all the fluid to pass through the coolers until the fluid is thinner and hotter. This method has worked great for me for years now.

**Bronco Boy** · 01-11-2016

Originally Posted by jbamonte

The only issue in VERY cold weather (below 20 degrees) is that the trans takes longer than normal (running through the radiator) to shift into overdrive (trans fluid has to be 88 degrees).

Won't shift into OD until 88*? I have never experienced that.

I can get into OD no matter what temp, but the torque converter won't lock until 69*. Many a morning I am on the freeway in OD with no converter lock-up.