Which 30 spline posi?

[toomanymodz]

In preparation for my new engine, I have decided to upgrade to 30 spline Moser axles and an aftermarket posi. I see three different units listed at Summit. I believe the first listing is what most folks use. A friend of mine told me a Detroit Locker is the best, and that any unit listed as 8.5/8.6 30 spline for a truck will work, as long as I use the larger bearings. I have run a locker on the street before and I didn't have any issues with it. Here are the three listings:

Eaton Posi $499
http://www.summitracing.com/parts/etn-19559-010

Detroit Locker $664
http://www.summitracing.com/parts/dtl-187c148a

Moser/Eaton Posi $559
http://www.summitracing.com/parts/msr-5e108530

What are you guys running? I'll be in the 9's next year and want to retain the factory rear. Thanks.

 

[OhioC5]

I think I'm going with the 19550-010, if you use the locker I'd like to know how it works out. I just searched on TB.com and came up with your thread. All this stuff is in my Summit cart. Carrier, axels and trying to figure out the right part number for bearings and what brand 3.42s to go with. The same Eaton carrier is $50 bucks cheaper on Amazon with free shipping by the way, Summit will price match.

But then I saw this one you posted and it has me thinking . . .MSR-5E108530

 

[Heskahoka]

Hi. I just went through this a month ago. Took me 2 days to spec out what I wanted for my new rear end. Here is what I ended up with:

Eaton 30 spline posi carrier Part # 19559-010
Timken Axle Differential Bearing Race (2) (for 30 spline Eaton unit) - Part # LM102911
Timken LM102949 Bearing (2) (for 3o spline Eaton unit) -Part # LM102949
Moser 10 Bolt 30 spline C-Clip Axles (2) -Part # A103004
Moser 1.400" C-Clip Axle Bearing & Seal Set - Part # 9563
Moser 12mm x 1 1/2" .505" knurl GM 12mm Wheel studs -Part # 8254
Richmond Gear Ratio 3.42 Ring and Pinion - Part # 49-0278-1
Richmond Gear Richmond Gear Differential Installation Kits Part - #83-1021-1

I went through 3 set of axles from Moser and Jegs: apparently they undersized the wheel stud holes on a batch of them so the 12mm studs would not press in. Jegs was awesome in helping me out with this.

The Eaton unit is working really nice now! I like it.

 

[bad V6]

Last spring I upgraded to the Eaton posi and 30 spline Moser axles with a TA Performance differential cover. I had a couple of 1.37 60' times at BG back in the fall, with one pass at 10.11 and another that should have been in the 9's if not for driver error.

 

[RYAN GRAVES]

I as well went through this recently. I went with an Eaton true trac., strange 30 spline st axles ta cover. willwood rear pro street rear brakes with rear end narrowed 2 inches and small bearing gm billet ends installed.
Eaton posi is good but the true trac is a clutch less unit. when you have a condition during an unequal tire bias it stresses the clutches. example; in the water box and one tire has more water on it.

 

[toomanymodz]

Ryan, is this the "True Trac" unit you are talking about? It's the least expensive of them all.

Eaton Detroit TrueTrac $404
http://www.summitracing.com/parts/dtl-913a481

 

[RYAN GRAVES]

Yes, that's the one. Operates the same as a positrac, but without clutches. It uses helical gears.

 

[OhioC5]

Thanks for all of the part numbers. Check out this video on how differentials work. Once you get past the motorcycle it gets better, stick it out.
http://www.tvraaca.org/aroundthecorneri.htm

 

[Hot Air]

Have you looked at Powet-Trax? Available from Jegs/Summit and you can install your self! Works pretty good,
Conrad

 

[Hot Air]

Power-Trax...sorry for spelling error.

 

[Slow91z]

I have a Tru Trac in my 99 1500 Chevy 8.5", Been there for 80,000 miles or actually a bit more.

Locks like day one when you touch the throttle, but off throttle turns like a open diff...don't know how it would hold up to a hard launching car, but I'd love to hear if someone does it.

 

[TexasT]

When the power tour came through town, I talked to the eaton people. He told me that the power trax was like buying a lifetime clutch that doesn't wear out like a clutch limited slip. The gears lock it so there aren't any clutches to wear out.

 

[Hot Air]

True. It is either locked or not. Nothing in between.

 

[toomanymodz]

Good info. As long as it can hold up in the solid 9's... I found some helpful pdf documents on their website too.

 

[horndog]

I know this is over a year old, but how is the tru trac for $400 working out?

 

[dank GN]

I have the true trac and it's working well so far

 

[horndog]

Awesome! I am going to build one since I am getting pinion bearing whine.