I picking up the heap from the shop tomorrow after getting 5.13's installed. I've done a search here (no where else though--I'm lazy), and here is what I've read about breaking in new gears;

Drive conservatively for the first 300-500 miles, then change out the diff fluid.
Also seen someone recommend allowing cool down periods during the break in period. I plan on asking advice from the install shop, but was wondering what you guys that have new gears did?

 

http://www.yukongear.com/Downloads/T...structions.pdf

Andy

 

Great read, thanks for the post.

So for those that want the skinny.

After driving 15-20 miles, let the differential cool before proceeding. 500 miles before towing and change the diff fluid at 500 miles. Also for the first 45 miles of towing, drive short distances (less than 15 miles and let the diff cool).

Sorry if this is redundant, but it sure helped me out.

 

What gears did you replace and how does it drive now? Also, what was the total cost of the re-gear?

 

I replaced 4.10's, and the word "peppy" is appropriate. Its not a race car by any stretch, but it is more responsive esp in 3rd thru 6th gear. RPM's are noticably higher, but it was expected. I think 5.13's are the most flexible gears in terms of use, ie. if you think you might go 37's, pull trailers, have an extremely large mother-in-law.......