Trac-Loc or Posi

D

Dahoopd

Registered User
Is this the same as a traction-loc or is this a real deal posi for the Ford 8.8? Is it any better than a traction loc if it is a posi unit? Thanks?
 
In the 1950's and 1960's many manufacturers began to apply brand names to their LSD units. The most famous of these was Chevrolet's "Positraction". Since then, Positraction (often shortened to "positrac" or merely "posi") has become a genericized trademark for LSDs.
Other factory names for LSD's include
Pontiac: Safe-T-Track
Ford: Equa-Lock and Trac-Lok
American Motors Corporation: Twin-Grip
Mopar: Sure Grip
Ferrari: E-Diff
Fiat: Viscodrive

This is taken from wikiedia.

Anyway, i've never taken them apaprt and compared them, but i understand that they are pretty similar and operate about equally as efeectively.
 
No it's not the same as the trac-loc diff. Last time I looked into it, the Eaton diff did not have the side gears machined to accept the circlips for IRS halfshafts.

I wanted the Eaton unit for my turbo car, but since it wasn't going to work unless I had the gears remachined, I decided to go with an Auburn Pro instead.

David
 
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David Neibert said:
No it's not the same as the trac-loc diff. Last time I looked into it, the Eaton diff did not have the side gears machined to accept the circlips for IRS halfshafts.

I wanted the Eaton unit for my turbo car, but since it wasn't going to work unless I had the gears remachined, I decided to go with an Auburn Pro instead.

David
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Dave,

How can I tell if I have a trac-loc if I dont have the code tag? I bought one off ebay to rebuild and paint but it didnt have a tag. My 93 also doesnt have the tag and I assume since its a 5-speed it isnt a trac-loc. How can I tell if the one I bought is.
 
Dahoopd said:
Dave,

How can I tell if I have a trac-loc if I dont have the code tag? I bought one off ebay to rebuild and paint but it didnt have a tag. My 93 also doesnt have the tag and I assume since its a 5-speed it isnt a trac-loc. How can I tell if the one I bought is.
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Might be wrong, but I thought that all SCs had Trac-Loc diffs except the 94/95 automatics. Something to do with needing the peg leg diff to work with traction control.

David
 
David Neibert said:
Might be wrong, but I thought that all SCs had Trac-Loc diffs except the 94/95 automatics. Something to do with needing the peg leg diff to work with traction control.

David
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that is very true. However I would be willing to bet in the year 2006 most of the trak loc sc's are now one leggers. Its just how it is ford makes a very good rearend in my opinion but they always loose their ability to spin both tires. Its simple actually they have clutches/discs in the diff and they wear out causing no friction so therfor one wheel gets all the power. I've seen cobras and newer GT's bust one leggers every now and again.
 
Here's a quick on topic question... I have a 91 SC, with an AOD and 3.73 gears; do I have a track lock? I can do 2-legged burnouts, so i am assuming I do?
 
From what I remember, if you have the rear wheels jacked up off the ground and turn one wheel, the other wheel should turn the same direction if it's a trac lok and if it's not, it will turn the opposite direction. Does that sound right?
 
Correct. And if you keep one whel on the ground, then use a torque wrench on the wheel of the side that's up, you can measure the effort necessary to turn the lifted wheel to test the status of the trac-loc.

Our generation of the trac-loc uses clutch packs and a S spring to apply the load to allow both wheels to lock. The eaton unit linked above, and other current generation trac locks use combinations of gearsets and clutches, or just gearsets (torsen) to keep the torque applied evenly.

Every Manual transmission SC has a trac-loc rear diff. Every automatic to 1993 has a trac-loc rear diff. 94 and 95 automatics have an open rear end due to the use of traction assist on those cars.
 
Thanks for the info, guys! I am gonna have the 'ol gal on the rack tommorow, so I will see which way my rear wheels turn.
 
Mike8675309 said:
Correct. And if you keep one whel on the ground, then use a torque wrench on the wheel of the side that's up, you can measure the effort necessary to turn the lifted wheel to test the status of the trac-loc.

Our generation of the trac-loc uses clutch packs and a S spring to apply the load to allow both wheels to lock. The eaton unit linked above, and other current generation trac locks use combinations of gearsets and clutches, or just gearsets (torsen) to keep the torque applied evenly.

Every Manual transmission SC has a trac-loc rear diff. Every automatic to 1993 has a trac-loc rear diff. 94 and 95 automatics have an open rear end due to the use of traction assist on those cars.
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whats that 5lbs?LOL
 
I'm little confused,so you guys are saying that we can't use trac-lock or posi out of ford 8.8 rear end with straight axles on our IRS.
 
Burbank95sc said:
I'm little confused,so you guys are saying that we can't use trac-lock or posi out of ford 8.8 rear end with straight axles on our IRS.
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You can use a trac-loc and several other diffs (torsen, auburn, ect) with the IRS, but not all 8.8 aftermarket diffs are machined to accept the circlips that help to retain the IRS stub shafts (eaton being the main one). All brands and types will work with straight axles.

David
 
We were putting mn12 cases with Cobra carriers in 03 Cobra's that wanted to retain the IRS and not implode the aluminum case. Auburn has seen 700+ wheel hp and no issues. No one here is making that power yet with their V6. Some of the higher HP guys might want to make a few phone calls to Drive Shaft Shop OR stop using drag racing as the required criteria to compair IRS cars. If you want to drag race, get a solid rear, if you want a nice high powered IRS car, STOP DRAG RACING. All problems solved.
 
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