factory 8.5 30 spline posi?

81rustabu

Dragway Regular
Apr 16, 2011
859
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pinckney,MI
Did GM ever make a good factory 30 spline 8.5 posi. i think my factory auburn has finally went.
 

prairiehotrodder

Pro Stocker
Dec 17, 2005
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Melfort Saskatchewan Canada
are you sure yours is 30 and not 28 ? I don't know the answer to your question because I've only seen 30 spline in 4x4 trucks and they usually have a govloc. If you indeed need a 30 spline posi I would go aftermarket. Eaton, Auburn or a powertrax lockrite in an open carrier are some options.
brian
 

81rustabu

Dragway Regular
Apr 16, 2011
859
0
0
pinckney,MI
I do have a 30 spline posi with aftermarket moser axles. My posi came out of a mid 90s caprice witch do have 30 spline axles. I'm just wondering if they made any better posi units that are factory?
 

DOUG213XRJ

MalibuRacing Junkie
Sep 18, 2006
4,661
1
38
West, MI
I would bet the aftermarket limited slips are stronger then GM.


Doug
 

Doober

Moderator
Jun 2, 2003
14,704
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38
Catalina, AZ
www.cardomain.com
I'm planning on a Detroit Truetrac whenever I build the 8.5 I have. No clutches and should hold up fine for the street, if I raced I would probably get the Detroit Locker, to my understanding it's stronger than the Truetrac.

 
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LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,848
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North Jersey
Truetracs are kind of weird. Most gear style limited slip diffs are. They sometimes growl or make funny noises, they sometimes make the car feel loose or move around when you lift off the gas in a corner. My new STi has a gear diff in the back and it does the same things as all lthe other gear diffs I've driven.

Tommy
 

malibu795

Pro Stocker
Apr 17, 2005
1,479
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36
spgfd ohio
The true track is definitely "different" in feel from regular clutch/cone posi..
Dodge uses the torsion diff design in there 2500/3500 trucks exclusively.

Never had one make noise... Had a ratchet diff make noise but that's not a torsion doff
 

prairiehotrodder

Pro Stocker
Dec 17, 2005
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Melfort Saskatchewan Canada
Auburn has a cheaper one and a better one. Not sure what differences there are besides price.
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,848
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North Jersey
prairiehotrodder said:
Auburn has a cheaper one and a better one. Not sure what differences there are besides price.

X2. Everybody goes for the Eaton, but the Auburn Pro series has much higher torque biasing.

Tommy