Re: Differential heater
 

For that matter you could probably completely drain the rear-end for one pass without damage.

Re: Differential heater
 

I helped on a Comp car years ago, where ATF was tried in the diff.
It ran E/SM at the time (old format) and right on the record.
It was losing nearly .10 each pass.
After 3 qualifying attempts, we could hardly push the car.
Tore it up pretty good...
Used gear oil from then on.

Re: Differential heater
 

That ^^^^ doesn't really surprise me. I never had the nerve to try it. I appreciate hearing that. The guy talking about running it all the time has a slow et bracket car. Like 13 seconds. He never mentiond testing it, he was just sure it had to be "worth something".

I ran it half full of gear lube for a couple of weeks. (Listening to the wrong guy) I had changed something else at the same time (should know better by now) When I filled it back up I picked up a good half a MPH with it topped off.

Re: Differential heater
 

Run Joe Gibbs qualifying oil,you don't need a heater with it. gsa612

Re: Differential heater
 

Wonder if anybody has tested that stuff?

Re: Differential heater
 

A few years back I went to a T&T, drained out the RP and put in the JG.My buddy brought his car we made a pass together he lost a hun.from his previous run (DA was the same) and I picked up 2.I left it in for another few races. I know some guys run it in B&C cars (12 bolt).Mine is a 10 bolt btw. gsa612

Re: Differential heater
 

I tried some stuff that looked like atf. The guy I got it from said comp and prostock guys used it. It wore out the ring gear in about 6 runs. It didn't break, it just wore down the teeth. I love superlight gear lube, but this stuff did not work for me. The redline superlight weight is great and I never had an issue with parts wear. I would think the gibbs stuff would be similar, but I have not tried that. Our car was a 2900lb stick stocker Nova.

Re: Differential heater
 

The discussion that prompted this thread was around gear and transmission oils. The JG qualifier, and the ATI (also JG) and the properties were the focus and the pro's and con's of heat put to them. I guess the qualifier rear lube doesn't really like too much heat put to it ,somewhere around 160 degrees or so, and some of these heating pads and elements go way above that. The synthetic trans oil apparently works the same cold or hot so that is a push.

As I was working on my diff ,I was curious just how a measureable amount of heat could be applied and if it was worth it. I have heard about the ATF in the diff before but no evidence of any good qualities of using it, I assumed the gears would be sacrificed, as rear drive diffs weren't designed for that type of lube.

PS thanx for the pm's some really great ideas out there, I love the outside of the box thinking

Re: Differential heater
 

Dion,

There are a few issues with this conversation. First off you really cannot take anyone’s advice on what to use in your combo unless they have the exact same combo right down to surface treatment on the gears. Where ATF may be the best choice for lets say a 4 cyl FWD 200 horsepower stocker its certainly not a good choice for some blown 900 horsepower new stocker. Its all about the pressure and surface speed on the gear faces. Best thing you can do is just try a few different oils and figure out whats best for your circumstances. You do not even have to rely on a time slip to do this. Just measure the differential temperature before and after a run. You can use a heat gun or a more accurate measurement can be taken but using an eye type thermocouple under one of your cover bolts. The fluid that causes the lowest temperature rise in a run is what’s best.
For those that want to use a heater it can easily be temperature controlled with the thermocouple under one of the cover bolts and a digital control. For me this is what I used to do when I ran 75 weight oil. The last couple years I have been running the Red Line super light and have no need to heat it

Re: Differential heater
 

Bill I know of some 1400 HP FWD cars that use ATF in their differentials They have a 170 plus trap speed.
Could be the gears are cut differently (Not Hypoid?). But they use it I know.