I installed a set of genuine GM 4.10 gears last week. They're completely quiet on the drive side and very little whine on the coast side. Maybe a thousandth or 2 difference on pinion depth would get zero whine. They are 2 cut gears and call for .004" backlash. Anyone wanting a better chance of no whine, get GM.

 

So are they the motive gears? where did you buy them from? Are you happy with the gains from them?

 

I got them from New Era. They were on sale for $169, but I don't see them listed now, and Master installation kit on sale for $70. The gears came in a Motive box but had GM OE written on the side. The pinion also had markings on the face just like the factory 3.42s I took out. I have a set of Motive gears and they are different. They compliment my cam well. About a 3.90 gear ratio would have worked well also but I don't think I'd want to go as low as 3.73 or any higher than 4.10.

 

So have you installed the motive gears? what are your opinions on them?

thunderracing has motive 4:10's with install kit including wheel bearings, Fluids,TA girdle w/ stud kit for 435$ which i think is a hell of a deal cause if you add everything up individually, its well over 500$ and add another 18$ to the 435$ for a soild pinion spacer which is reccomended to help from the gears moving around since the crush sleeve will eventually wear out

 

Motives are probably fine but make sure whether they have 2 cut or 5 cut gears. The pattern they make is different and if you try to get a 5 cut pattern on a 2 cut gear, it'll never work. I was trying to get the wrong pattern on my Motives and they whined. I then ordered the GM gears which came with different instructions than the Motives came with and I learned that I was trying to set up the Motives wrong. Now I have an almost new set of Motives for paper weights. I guess if my GM gears ever go out, I've got an extra set.

 

hmm not really sure what you are talking about on the 2 or 5 cuts

 

Here's the jist of it: http://www.geocities.com/MotorCity/Downs/4013/re.html
Also, the tooth height on a 2 cut gear is the same at the heel and the toe.
The height is different from the heel to the toe on a 5 cut gear.

 

ktg what kinda tires/wheels do u have and are u getting any traction with the new gears? (sorry if its a little off topic)

i'm installing the same cam that u have and thinking about 4:10s for my 10-bolt.i figure i can stay w/ my 10-bolt as long as i don't go for big tires and hard launches.

 

I'm running 18" Smoothies II with Pirelli PZero Nero M&S 245/40R18s. I've been taking it easy but I haven't spun a tire yet.

 

on that webpage it says to add 2 bottles of Gm posi additive...i thought it was only one bottle? what happens when you add two bottles?