4.10 8.6' gears...... came with zero information from randy's ring and pinion. my rear end guy wants all available info for the install. pinion depth, backlash...... etc....

any tips on installing the detroit true track, with gm 4.10 gears and yukon axles, with a girdle cover are extremely appreciated!!

thanx guys.

 

Hmm, my guy knew that stuff already, didn't need any info.

 

this guy doesn't do it for aliving( set gears) but he's a genius with everything technical, and has set up plenty of rears. and he knows the standard stuff. He told me before my gears arrived, that gm doesn't provide any numbers with their gears. ( unlike richmond, etc.... ) he just wants to verify. because from what we both kinda already knew.... 8.5" wants 10 thousandths backlash, while an 8.6 wants 6 thousandths. we just want to verify all numbers from someone who positively knows.

 

In the old days chrysler sent there gears out with info +1 or -2 for example.For yours there is nothing to know except back lash,you want it about .04-.06 which is tighter than the old days.Measure your backlash before you take it apart.The best way to start is to pull off the inner pinion bearing to retrieve the shim for depth more often than not it is .035 (report back what it was)reinstall that shim on the new pinion,new crushsleave,make certain it gets crushed TQ preload to specs,swap ring gears reassemble with the OE side spacers,make sure they go back on the same side they came out same with the caps.check backlash and pattern.Thats the basic version rundown

 

i just installed some 3.90 yukon gears that i got from randys ring and pinion, and still have the install booklet if you think that would help. granted these are yukon's and not gm, but the info in it came from multi-sources including gm. let me know if you want it and i will scan it and send you a link to it.

here are some of the specs it calls for:

8.5/8.6 (Old 5 step)
Pinion Preload New - 14-19
Used - 6-8
Backlash - .006-.010
Ring Bolts - 65
Cap Bolts - 60

8.5/8.6 (New 2 step)
Pinion Preload New - 14-19
Used - 6-8
Backlash - .003-.006
Ring Bolts - 65
Cap Bolts - 60

 

i have never looked at any install booklet for gears and such. i always pulled the rear end apart, took the ring gear off the posi unit, replaced it. pulled the pinion out and replaced it. i always do the paint on the teeth to ensure the gears mesh together well but other than that, it was never a problem. honostly, it is a simple procedure. you just can't be scared to do it.

 

i'm thinking about doing this myself, since my guy doesn't have the time for like 3 weeks. i'll start a new post.