[vicgto]

Is anyone running the Auburn 546033 Cone type differential on their 12 bolt. Is it reliable, any issues with the cones not locking? The picture shows that it's a 4 pinion, is this correct, how do you get the C clips in?

[b-man]

I don’t know anything about that unit but the axles may require that you use a C-clip eliminator kit.

[AG]

With the options out there it would be the last posi I would buy. A TruTrac or clutch type would be better for longevity.

[68 Firebird]

no issues so far in my 10 Bolt with 3:08 gears

gerry

[Formulajones]

I've had one of those cone style Auburns in one of the 12 bolts here for what has to be 25 years or so. Has worked fine all that time with a lot of drag strip passes and burnouts. I've noticed it's starting to show it age though when I'm on a prepped track sometimes it slips and spins one tire. On the street it's fine.

Biggest issue with those is they aren't rebuildable so it's destined for a door stop.

If clutch style units are what you're looking for I prefer the Eaton units, as they are rebuildable and parts still available for them. Tru Trac's are nice and I use them in a couple cars. My only complaint is they don't offer a 12 bolt 4 series Tru Trac for 30 spline axles. I either have to go up to 33 spline axles or drop the gear down to a 3 something for the 3 series carrier.

[455dan]

This is info from Kern Osterstock many, many years ago.
The Cone style has one advantage and that is not losing control 'as easily' in a corner where the car is at the traction limit. By backing out of the throttle the cones release allowing the tires to track through the turn. The Eaton unit using springs and clutch plates is less forgiving at the limit and will attempt to keep the tires locked together. This as to why H-O racing went to the trouble of modifying a GTO 4 pinion auburn cone style '10 bolt" and chose it for use in their second gen TA that H-O built for street strip use.
The axle bearings are pressed on as is the bearing retainer, so no c clips inside the 3rd member. YMMV

[Steve C.]

At one time Auburn had an exchange program for a new unit. Send it in and for a modest fee they would provide a new one, this to counter the bad rap that they are not rebuildable.

For years I ran a Auburn unit in my heavy TA running into the 10's. When we switched motors and decided to play with nitrous we installed a spool. At that time I sent the Auburn unit back to the factory under their exchange program and they sent me a brand new one for a very modest service fee. No more nitrous and that Auburn unit is currently in my car now with the 505 street motor which is still capable of running 10's.

Rear end: GM 12-bolt, Moser 30-spline axles, 3.73:1 gears, Auburn posi.


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