Idea about pump for ZF tranny cooler installation

[smokin150]

If ur still having heat issues, i contacted zf after installing my gauge and seing temps in excess off 270-300 deg, they told me that if heat is an issue, use an lv-75/80 weight synthetic gear lube, and if the problem still exists to check the main shaft bearing. Been running about 210-220 since the change and i carry 70000lbs around every day. Normal opperatiomg temps on this trans are 160-210, higher temps under gcw towing but should never exceede 250* . Thats directly from the mani

 

[BrandonMag]

If ur still having heat issues, i contacted zf after installing my gauge and seing temps in excess off 270-300 deg...

I have seen my temp. gauge get up to 280* while towing and 220* while driving unloaded.

...they told me that if heat is an issue, use an lv-75/80 weight synthetic gear lube...

What is an "LV-75/80" synthetic gear lube?

...and if the problem still exists to check the main shaft bearing.

I pulled my transmission and transfer case in March or April and took them both to a local transmission shop. He pulled them both apart and replaced a couple of seals, but said the internals of both the transmission and transfer case looked great. I actually got to see the inside of my tranny, I took some pics but can't find them right now.

Been running about 210-220 since the change and i carry 70000lbs around every day.

When you say you're now running 210-220 since the change, are you saying since you started using the synthetic gear lube or your old main shaft bearing was bad and you had it replaced?

 

[BrandonMag]

I just got off the phone with ZF North America. The guy I talked to said the reason I'm seeing such high temps while towing is because I'm using overdrive while I'm going down the highway. Evidently, these trannys create quite a bit more heat while in OD than in 4th.

But here's what really surprised me. He said 270* is not an abnormally high temp while towing. Obviously, you don't want your tranny temp. that high for 10 hours straight, but running at that temp for awhile isn't going to kill the tranny. A lighter gear oil (75W-90) may help reduce temps as well. He also said a possibility would be to try Castrol Transynd (Allison commercial-grade ATF).

My next step is to install one Fast Cooler (on the RH side) and refill it with some new synthetic ATF. I may go down the gear oil route, but I've got a gallon of AMSoil synthetic ATF left over from last year, so I'll give it a whirl and see what happens.

I will report back on temps while towing and driving unloaded.