i am installing temp guages for my diif's and transfer case and was wondering what the temp rang should be. also what is the max temp were mechanical failure can start to happen.

 

Standard gear oil begins to char at 275 degrees F. If you get the gear boxes up to 300 degrees you should have the oils changed at the earliest possible opportunity. This is with regular oils. I don't know if synthetics make a difference. I would think so based on the advertizement from Mobil showing them cooking oil on a stove top.

You are going to have to really work your gearboxes to get the temps up. In a "big rig", we regularly haul 80000 lb. trucks up hills like Baker, CA which is 19 miles of pretty steep hill, pumping 500 plus HP and ungodly torque into those gear boxes without having to worry much. Bringing it downhill on the Jake, using lots of reduction to keep speeds in the 20 - 25 MPH range seems to heat them worse. That said, I've only once had mine heat to where I had to change the oil. I know you're talking about a pickup, and all this tractor-trailer stuff may not be relevant, but it's the only experience I've had.

So, bottom Line? I'd guess your gears should run about 150 to 175 going down the road. I'd look for maybe 200 when off-roading and working them hard. 300 degrees would warrant looking for something wrong.

Hope this helps

Flagship

 

thanks for the info man

Dan