Johns98TA

iTrader: (2)

OK so I am putting Motive 4.10's in my stock 10-bolt rear in my 98 TA as we speak. This is a true 4.10 with a 10 tooth pinion. I replaced all the bearings and seals. Right now I've got a good contact pattern and about .003 of backlash. It's turns smooth as glass, but I know it's supposed to be minimum of .008 backlash per the instructions. My question is: What will happen if I run it at .003 instead of loosening it up to .008? What is the best recommended setting for QUIETEST operation? I dont care about strength, I want them QUIET. Thanks for your help!

alamantia

iTrader: (10)

i thought motives were 0.006 - 0.008
AAM 0.004 - 0.006
Richmond 0.006 - 0.010

those are just what i have heard the manufcture suggest, i have also heard that rule of thumb was 0.001 for every inch of diamter the ring gear is, i believe chicane suggested that. As for running them too tight, im not exactly sure what dammage would occure

EPMD

iTrader: (4)

I just put a set of Motives in my car this past weekend. The recommended backlash with the gear was .008 to .012. Ideally you want in the dead center of that. The closest I could get was .008. I have put about 100 miles on the gear. It whined a bit at first but the whine is getting quieter and is almost gone. I was told this is because my backlash is loosening up a little.

Cap'n Pete

iTrader: (2)

The two sets of Richmond's I've installed (3.73's & 4.10's) have said "0.008", +/- 0.004", which means a range of 0.004" - 0.012".

My Motive 3.90's called for 0.008" - 0.012".

IMO, a gear is a gear is a gear. They're all made of steel, likely of similar/same physical properties.

Since Richmond calls/allows for the tightest setting (0.004") then I'd say that's probably the limit. Keep in mind, with a low ratio such as a 4.10, they're going to be spinning really fast inside that diff. They're going to build a lot more heat (I would assume ) than a higher ratio like ~3.42's. As the gears heat up, they will expand, and the backlash will tighten up. Tight backlash is a good thing (esp. for drag racing) but too tight, and you're going to start chewing the gears up when they get hot (long drives, heavy loads).

Go back to the drawing board!! Shim'er a little to the left! I'd personally aim for ~0.008" with just about any gear. +/- a couple is good.

theblur98ss

iTrader: (71)

I've always heard .010

samdogmx

iTrader: (14)

if they dont make any noise run them for a couple hundred miles & then re check, they will loosen up. The first set of richmonds I did were initially setup with .006 I rechecked them 200 miles later & they were at .008

Cap'n Pete

iTrader: (2)

... and a guy at a gear/driveline shop told me he always aims for ~.006" - .008".

Realistically? I think Richmond probably has the best advice. 0.008" +/- 0.004" .

Although for further confusion into the mix ...

... without looking at the paperwork, I believe Richmond calls for something like .020" - .022" for circle track setups ... basically, a setup that is going to be run long and hard. Completely opposite from drag racing.

SO, what do we gather from all this?! Tight for drag racing, loose for roundy-round racing, and probably somewhere in the middle for street/strip .

john.kiley

I know this is an old thread, wondering if you decided to send it or not and what was the final outcome. Thinking of sending and old used 4.10 gearset on .003.