What limited slip differentials do others like for use in an 8 1/4?

I saw slantzilla mention that the trac loc units don't like too much horsepower, can anyone add more details to that statement, what is the most horsepower I should expect from these units?

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'66 Dodge Dart

Bump. Nobody has an opinion on this?

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'66 Dodge Dart

I like the way True Tracs and torsens work.


Don't know if they exist for 8.25..........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Go to randys ring and pinion.com I dont know what is the best though...

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~Nic

bought one from randy's ring and pinion worked well in my truck

The Auburn Trak-Lok style limited slip is fine until you start doing high RPM clutch dumps. With an automatic I would run one in a 400hp car no problem.

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Joshua

emsvitil, I'm also a fan of the torsen-style differentials! The promise of no special fluids and no rebuilding of clutch packs is extremely attractive. It looks like you can get a True Tracs for the 8.25" but they require the 29 spline axels, which apparently you can also get in a variety of lengths. It would be really expensive ($850+) but it could be done.

Josh, do you prefer the Auburn Trak-Lok style over the Dana Spicer Trac-Loc clutch style limited slips? The possibility of rebuilding the differential rather than buying a new one seemed attractive to me.

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'66 Dodge Dart

For drag racing and road racing I prefer the multiple-plate clutches of the Dana Power Lock, but they have no preload requiring applied drive torque for their lockup and so do not work well on slippery surfaces like snow and ice where the drive torque is very low. The Auburn units have spring preload and therefore work better on low traction surfaces. High end race differentials like the OS Giken are multi plate.

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Joshua

Great info Josh, thanks for clarifying!

Looks like the factory style Dana/Spicer Trac-Lok uses some amount of sprint tension from Belleville springs behind the gears (http://www2.dana.com/pdf/5313-3.pdf). Not entirely sure how effective it'll be on very slick services but it doesn't matter much. I think I'm going with this option since it is rebuildable.

Now that I've settled on a limited slip I need to choose either the 27 or 29 spline version. I've got both 27 and 29 spline axels so it comes down to which differential will work better and have more parts readily available (or do all parts, and replacement clutches interchange?). If the two units are identical (other than the splines on the spider gears) I'm slightly leaning toward the later-style 29 spline unit since it seems very popular with the Jeep crowd. Thoughts?

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'66 Dodge Dart

(QUESTION)
I got a 8.25 axle in my 79 d-100. How do I tell if it is a 27 or a 29 spline? Do I have to pull the Diff cover and count it or is there a easier way? I only ask because I get both options on randysringandpinion.com

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~Nic

8.25 axle spline count was 27 until 1996. Starting in 97 spline count went to 29.

To find out what you have, pull and axle and count the splines on the inside of the axle shaft. These must match the number of splines in the carrier housing or the axles won't fit the carrier.

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Casually looking for a Clifford hyperpak intake for cheap.