y2keglide

iTrader: (2)

Ok so I've pretty much decided that I want 3.90 gears so I don't care to debate other ratios and I plan to upgrade to an Auburn posi unit at the same time. Some seem to prefer Eaton over Auburn? what say you all?
Or is there a third choice like Yukon I should consider?
I've been looking at sites like Summit and Jegs and I see Motive and Richmond both have the 3.90 gear sets and not many others are available so I guess it's one or the other. Interested in opinions on these gears and what most think are the best or again a third choice and why?
I also see there are two different 10 bolts, a 7 1/2" and a 7 5/8".
So how do I tell which I have (M6 car with I assume 3.42 gears) and does it make a difference when ordering parts?
Car is an '01 LS1 SS M6 with the LS6 intake and getting LS6 Z06 heads with a pretty aggressive cam and of course long tube headers etc. so a pretty good bump in power over stock. Not drag racing this car so I don't plan on upgrading from the 10 bolt so let's not debate that please.
I've used the search feature already so if I missed something don't beat me up about it. lol
All opinions welcome and thanks in advance.

FirstYrLS1Z

iTrader: (4)

GM 10 bolt 7.5 and 7.625 are the same,same internals. Only time a discrepancy would occur is with axle/carrier spline count. Older ones have 26 spline,your 01 has 28 spline.
If your 01 came with the OEM factory line carrier,it would be a Torsen. I prefer Eaton(clutch pack posi) AND Auburn(cone clutch posi) equally.
Your 3.42s would be on a 3 series carrier and 3.90s are ONLY available for a 3 series carrier.
Most here would recommend the Motives.

y2keglide

iTrader: (2)

Thanks! Much appreciated.

01ssreda4

iTrader: (96)

Motive G875390 is your part number. These are only available in their "orange" box performance series gear, which in my opinion is prone to a little noise (whine). If you're ok with that go ahead.

https://www.summitracing.com/parts/mgr-g875390

y2keglide

iTrader: (2)

Thanks,it's not a daily driver so as long as it's not real noisy it shouldn't be a problem.

y2keglide

iTrader: (2)

I think I'll try and find a package deal first that has both the gears and a posi unit and maybe the installation kit. If it's not out there then I'll piece meal it together.
Worth a shot to search even if it's a long shot.

y2keglide

iTrader: (2)

This set looks like a pretty good deal,any opinions?
http://www.quickperformance.com/GM-7...t_p_20409.html

2ToeRacing

iTrader: (5)

Thats a great deal. I redid the rear in my S-10. I bought a Alburn carrier,3.42 gears,install kit. It was about 900 bucks.

y2keglide

iTrader: (2)

This isn't the Aubun posi unit though and this gives me pause "10 Bolt Eaton Style Clutch Posi Unit". There are good reviews but what does "Eaton Style" mean?
I'm guessing a China made knock off which may or may not be fine, China made quality is all over the place. I may have to find out more about it, wonder if a true Eaton brand part is made here still?

01ssreda4

iTrader: (96)

Im sure its fine, and yes buying a kit is cheaper. An auburn is gonna run you 375ish, gears 150-250, and a rebuild kit 75-140 depending on brands, thoroughness of the kit etc. Im particular about what I want so I usually end up buying individual pieces. I recently installed a powertrax diff and national drivetrain gears in a buddies truck and its been flawless, and the gears are dead silent.

01ssreda4

iTrader: (96)

Auburn is gonna have clutch cones, pushed together with springs and require oil additive so they slip and engage correctly. A torsen or true-track gear driven posi is pictured below, and requires no additive.

FirstYrLS1Z

iTrader: (4)

Post #9 got me curious,'Eaton style'. Sent an e-mail to them asking if it's an Eaton or an offshore copy.
The $355 price for the Eaton seems about right compared to the Auburn $455 price. Auburns' are pricey.

01ssreda4

iTrader: (96)

Auburn $375

http://www.ebay.com/itm/AUBURN-GEAR-...ZYbPyY&vxp=mtr

The Auburn pro seems to be more in the 450-500 range.

madmike9396

iTrader: (29)

I honestly would not waist the $ on a 10 bolt. Save for something better since your m6

y2keglide

iTrader: (2)

Covered that in my first post

FirstYrLS1Z

iTrader: (4)

The little 10 bolts(whether Auburn or Torsen or Eaton) are fine when they're not driven/used in an abusive manner. How many millions are out there that are doing fine,Camaros,Firebirds,S10 trucks,S10 Blazers.

y2keglide

iTrader: (2)

I just sold an S10 pickup with 270,000 miles on it, no rear end noise at all.

y2keglide

iTrader: (2)

Yeah and this one is for an early 26 spline, mine is a 28 spline being an '01.
Pretty good price but the wrong part.
I'm in no rush just doing my homework for now, still looking for the right package deal with a set of 3.90 gears and hopefully the install kit too.
The car will be going to the tuner for engine upgrades in April or May,if my budget allows I may do the gears at that time and if not it'll have to wait.
Here's the right one,a bit more money and only one left. http://www.ebay.com/itm/AUBURN-GEAR-...hYbPya&vxp=mtr

hurley711

iTrader: (5)

Enjoy the 3.90s! Woke my Trans Am jumping from 3.42s.

y2keglide

iTrader: (2)

Good to hear that, didn't figure 3.73's would be enough of a change to be worth it and felt 4.10's were a bit lower than I wanted to go besides being prone to breaking with thin gears.