rear gear break-in, fact or fiction?
 

Is the 500mile break in period for new rear gears fact or fiction?

Is there a break in period for new LSD's?

From my personal experience with gear installs. First set I just hammered on them right out of the shop. About 9 months later the gears failed and destroyed my posi/bearings/gears. 2nd set I broke them in and didn't hammer them till after 450miles. That set is still in my old truck.

I think it is a good idea to take it easy for a while after getting something like that installed. Let's everything settle, wear in a bit. Drive train item are kind of like that. You take it easy on a new engine, new transmission, why not the differential.

Common sence goes a long way here. First and foremost, use quailty parts and dont cut corners on the fluilds because you spent too much on the parts. Improper pinion depth and backlash are the most common causes of gear failure. Dont let your sister put your gears in.

New gears should be put though three 20 mile heat cycles. After the install drive the car like Granny for 20 miles and stop. Let he rear cool down for 1 hour and repeat 2 more times. Change the fliud every 36k.

Then drive the "Sumbitch" like you stole it.

X2. It's important to establish the proper wear pattern to prevent breakage, whinning, etc. Also, I'd run the cheap stuff initially since after break-in, you should change the fluid (at around 500 miles). After that, you should use a good synthetic.