• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rear End Break In


Well-Known Member
Local time
5:38 AM
Oct 5, 2017
Reaction score
Plant City, FL
I pick up my car from the shop that installed the new rear end gears in my dana60. I now have a 4.30 gear on a spool in my 64 dodge NSS car. I asked the shop about break in and he gave me a procedure that will take a LONG time to get through given that this is a pretty dedicated race car. What is a good, common sense, break in procedure? I am eyeing a track day this Sunday. That will leave tomorrow to do any break in. Gears and spool are from Strange Engineering. Comments/suggestions greatly appreciated.
I would do a couple easy passes. Everything sounds good, let'r rip. After your track day, if you’re concerned, pull the cover and change the fluid. Check everything out while it’s open.

I personally don’t subscribe to the lengthy break in procedures some have recommended. Any that I’ve put together get a very small amount of test time. After they get to temp and don’t get hot, they get beat.
I put the car on Jack stands under the rear diff. Fire it up and put the trans in first gear. Let it run for 20 minutes to a 1/2 hour at 30 mph. U can also run it in second gear. U will have to speed the idle up. Kim
Jack stands under rear axel. 15 mins in 3rd gear and cool then 15 mins in reverse. Cool and go race. Change gear lube after a weekend or two. Get warm before you dump. Dave
I have never done any kind of break in with a spool. Just run it. If it's a sure grip. I fill with fluid and adding the posi additive. Go to end of my subdivision and do figure 8's a few times to load the sure grip from both sides and then run it from there.