how long it take for rear diff to get up to normal

[MetalSlug]

how long it take for rear diff to get up to normal temp ? im about change out the rear diff fluid on my mustang. I cant drive on the highway or street yet, cause I dont have a tag or insurance for it yet. I can drive around my neighbor hood. I want it to get up to normal temp before I drain it. you guy think 5-10 min driving 10-15mph around neighborhood will heat up the rear diff before change it out the fluid.

 

[Loobed]

get a hot plate and put in underneath the ear end for a few hours. When I road a motorcycle to work and it was freezing outside, I had to put a hot plate under my engine and have a timer turn it on 1 hour before I went to work. The hot plate was on the ground about 5 inches below the engine. I didn't have a garage to keep the bike warm.

 

[Jim Allen]

The temp generated is proportional to the speed and/or load. The fastest way to get up to temp is highway driving. The smaller the oil capacity, the faster it will warm up and I only know from large capacity truck axles. In 5-10 minutes, 10-15 mph I doubt you'd get it up to 100F. Depends on the starting ambient temp. Loobed is onto a good idea. A small heater/hotplate for a couple of hours. Otherwise, pull the cover or drain plug and let it drain all day. You'll get as much as you would with a warm diff... albeit more slowly.

 

[mount]

If you do heat it up with some sort of heater, I'd still drive it a bit to get everything mixed around and in suspension before you drain it.

 

[MetalSlug]

thank.

 

[Eddie]

Your 10 minutes drive at 15 mph is enough in my opinion. Heck, guys drain them overnight cold. Ed

 

[artificialist]

The other consideration about how hot it gets is how well air flows over the differential housing, and how well that housing is built to cool off the fluid. Cars with low ride height heat up fluid quickly because of this. Some people buy diff covers that are made out of aluminum and have huge heat sinks to speed up cooling.

Anyway, I just drain the fluid at whatever temperature the car is at as it drives into my garage or space at the auto repair shop.