33 splines posi

Malibu ss 64
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33 splines posi

Postby Malibu ss 64 » Sat Jan 24, 2009 10:43 am

Have a 12 bolt passanger question. Just upgraded my rear to 33 splines
axles. Used my almost new 30 splines Eaton posi and opened the holes 020 more
than the new axles and changed spiders. Now after I heard a couple of horror
stories that a 33 splines unit will break cause the opened hole to accept the
axles? searched all over the net and could only find one broken 30 spline unit
but the problem seemed to be a bent housing? Do you think I shall be worried?
Also heard a truetrac is made from better material than regular Eaton posis?
Know 33 splines Truetracs that hold up for nines, so shall I change my Eaton to
a Truetrac? How much is a 33 splines Truetrac?
My car is a chevelle 64 3500 lbs
489 BB 570 hp
th 400 2800 in stall
3.73 rear
Going to visit the strip a couple of times a year with slicks but most street
car hoping for low 11`s.
Whats your experinse? Will my Eaton hold up fine for a couple of years? and
than maybe after several years only need new clutches?

Marcus

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monzaz
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Location: RICHFIELD, OH

Re: 33 splines posi

Postby monzaz » Mon Jan 26, 2009 9:43 pm

Marcus, Welcome and thanks for the great question.

First is the Eaton a stock GM unit or aftermarket unit?

IF it is a GM unit you maybe looking at some trouble times coming with too much torque.

The Aftermarket Eaton and TRUE TRAC unit are better cast units then the OLD metallurgy use years ago.

Most reasons for failure is a casting flaw OR HEAT in the bearing journal usually resulting in a BEARING hub failure as complete breakage of that area. Perfect example would be the 1990 -1998 GM 10 bolt 8.5 30 spline upgrades units and GM NEVER upgraded the carrier hub journal, they also just opened the internal diameter and on most heavy towing and plowing on truck the bearing will fail and the carrier hub literally breaks off...causing major catastrophe.

We sell the TRUE TRAC unit for.... $439.00

10 dollar forum use discount...lol. Jim :)
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J D Race

Malibu ss 64
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Re: 33 splines posi

Postby Malibu ss 64 » Tue Jan 27, 2009 1:01 pm

Thanks!

It´s a aftermarket eaton limited slip unit with carbon clutches and 400# springs, it´s 3 years old. So you think the hub/journal will hold up fine?

Have you seen or heard of any troubles with hub/journal on 33 splines posis/spools? if a Truetrac holds in the area for a 700 hp high nine car I guess the Eaton will hold for my 570 hp and hopfully low elevens car?

Asked a couple of rearend companies(moser, mark williams and toms differential) and they never heard of the problem.



Marcus

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monzaz
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Re: 33 splines posi

Postby monzaz » Sat Jan 31, 2009 8:34 pm

You should be fine with any aftermarket posi unit. I would go for it. If it were a GM stock unit I might double think it. So I would do it.

Seems like you have a go from all. :) Jim

Thanks for using the site... Much appreciated
J D Race

Malibu ss 64
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Posts: 5
Joined: Sat Jan 24, 2009 4:40 am

Re: 33 splines posi

Postby Malibu ss 64 » Mon Feb 09, 2009 2:37 pm

Thanks!

Going to run it as it is! Just wanted to be sure.
Great forum!

Heres pics of my rear.

Axles spiders etc.

Image

New ends.

Image

Welded tubes.

Image

Painted and ready to install-

Image

And the car.

Image

The engine. 489 cui mild hyd roller setup 570 hp.

Image


Best regards!

Marcus

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monzaz
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Joined: Tue Nov 13, 2007 7:56 pm
Location: RICHFIELD, OH

Re: 33 splines posi

Postby monzaz » Wed Feb 11, 2009 9:41 pm

I see Tom's stuff...Good choice GREAT guy. You should be in good shape. :) Jim
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