I have a worn out limited slip in my camaro and I'm wondering what would be the best unit for dounuts and drag racing. And also how much abuse the stock 26 spline axles will take given my heavy right foot. I currently have my eye on a detroit truetrac.

 

Its been talked about before in other Rear end threads but ill give a brief coverage of how i understand everything. ALL Third gen and 4th gen rears are not all that strong. The weakest of them all are 26 spline 10 bolts. 28 spine 10 bolts (90-92) are stronger and can take a bit more abuse. 9 bolt rears are about the same as 28 spline 10 bolts if not a bit stronger, but have the advantage that they dont have C clips holding the axles in. Instead they are bolted in at the wheel bearings. They are also 28 spline but the disadvantage is they are harder to find parts for. 4th gen rears are too wide for our cars to the point you would need specially spaced wheels to run them (4 gen camaro wheels). Basically it comes down to, if your hard enough on any of these rear ends you will break them. Its just a question of when. And if your putting more power to them then stock that time frame of when they die will get shorter and shorter.

 

The Eaton posi is the best for these rear ends. You can tune them for your needs. The clutches can be swapped and the preload springs can be swapped. There are about 3 different types of clutches and 3 different preload spring rates. You can also shim the clutches for better performance. When it wears out many years from now you can rebuild it.

 

Detroit TrueTrac or an Auburn. Both are gear style LSD's. They cost more than an Eaton, but have much longer lifespans.

 

If I am not mistaken Auburn posi still uses clutches, they are conical instead of flat.

Just found this info from another site, hope it helps

POSITRACTIONS / LIMITED SLIPS

Auburn Gear (AG)
The Auburn Gear limited slip uses a cone style clutch that wears directly against the carrier case and provides the friction force to make the unit work. This design is not rebuildable. Once the cone clutch or case wears out, the entire unit must be replaced. Even with this shortcoming, this design works well for occasional use where extra traction is needed. They have good impact strength in passenger cars and trucks up to 1 ton. They will hold up well to high horse power, but will not last long if there is a lot of tire spinning. (aftermarket ) 1 yr warranty

Auburn Gear PRO (AG)
Also cone style & not rebuildable. Designed with more lockup force than regular Auburn Gear limited slips. Will provide better high performance traction than regular Auburn Gear, but still wears out under extreme off-road use and heavy wheel spin. This design tends to chatter a lot and is not recommended if the customer is looking for a smooth unit. (aftermarket ) 1 yr warranty

Detroit Locker (DET)
Heavy duty. Probably the most durable design available, the king of traction differentials. Usually causes banging and clunking, but gives 100% lock-up whenever traction is needed. Unlocks when negotiating a turn so that the outer wheel can turn faster than the ring gear is turning and the inside wheel are turning. Does not need any interaction from the driver. New Sof-Locker design has damping device to reduce banging and clunking. Includes carrier case that is stronger than stock except in 2 applications where the original factory carrier case is used. Only the 10.5" 14 bolt truck and the Nissan V6 designs use the factory carrier case and these cases are both very strong. (aftermarket ) 1 yr warranty

Eaton (EAT)
Clutch type, similar to Trac-Lok in design, yet far stronger like a Power-Lok, and, more aggressive and better lock-up similar to the Power-Lok design. These units came as an original equipment option in 65-72 12T (12 bolt GM truck), 12P (12 bolt GM passenger), 8.2" GM pass, 63-79 Cast Iron Corvettes. The original OEM 12T case was very weak, but the new design replacement from Eaton is very strong. 4 preload springs and 2 steel preload spring plates. Latest design uses HD nodular iron case, forged side and pinion gears, no-chatter, race-bred, carbon fiber clutches for extreme strength and longevity. Old design, all steel clutches which are still available in 18 or 22 clutch designs for those who need more lock-up and are not bothered by clutch chatter. For even more lockup customization, there are also 4 levels of spring pressure available (3 from Eaton and a fourth from GM) that can be used to vary the clutch preload from 200 lbs. to 800 lbs. Originally used in mid sixties GM muscle cars and trucks. This unit is now available for Ford applications and soon will be available for Dana Spicer, AMC, and Chrysler applications. They have a high tolerance for abuse in high horsepower vehicles. Recommended for everyday driving and severe off-road use (factory GM )

Detroit Truetrac (TT)
Based on the worm gear principal and works like clutch type positraction. Does not wear out, not recommended for tall tires over 33".

Detroit Truetracs are similar in design to the Gleason Torsen®, only the Truetracs hold up well with reasonably tall tires. They use worm wheel gears that work on the same principle as a worm gear. When the unit is loaded, the worm wheels are forced away from each other and against the case. They develop locking torque by the light friction between the worm wheels and the case. This light friction is multiplied by the ratio of the worm wheel which depends on the size of the worm wheel relative to the size of the side gear. The manufacturer can change the amount of torque biasing or lockup by simply changing the diameter of the gears, or the pitch and spiral of the teeth. A larger difference in the size for the worm wheels and side gears (smaller worm wheels and larger side gears) will increase the lockup force. Increasing the pitch and spiral of the teeth will also increase the lockup forces. Like everything, there is a limit as to how much lockup force is reasonable. Making the unit too "aggressive" will cause tire scrub during everyday driving and will cause the unit to wear out too quickly. All of the feedback that I have received from customers indicates that the unit works very well for mud and snow, while going unnoticed during every day driving. When used in situations like rocky trails where one wheel gets off the ground, the unit will not lock up 100%. Light application of the brakes will help the differential engage more transferring power to the tire that is still on the ground. For extreme situations where the vehicle will have one wheel in the air often a locking differential provides better power transfer to the wheel on the ground.

Detroit Truetracs are designed for medium duty 2WD and 4WD applications. They work well in the front and rear, and are so smooth that there is little or no hint of resistance in the steering wheel when used in front drive steering axles. Like the Gleason Torsen®, the Detroit Truetrac does not bang or clunk, has no clutch chatter, does not wear out like clutch type positractions, does not need limited slip additive, and needs no preload or clearance adjustments.

Almost sounds too good to be true doesn't it? The only drawbacks to the Truetracs are their inability to provide lockup 100% like a locking differential can. Although Gleason no longer makes the Torsen® differential, the Detroit Truetrac is a proven design that is available for many popular applications. (aftermarket) 1 yr warranty

 

Auburn is a cone style limited slip and will not last long. They also fill the rear end with powdered metal as they wear. They can not be rebuilt when they wear out, and can not be tuned very easily. The Trutrack has some lock up issues when doing burnouts.

 

What kind of lock-up issues are you talking about???? I really just want a fresh lsd so I can do some sweet dounuts and added traction at the track but that's not my main concern. So more then likely The 28 spline for sure but would the Truetrac give me what I'm looking for????

 

Rat, didn't know that about Auburns so thanks for the info.

big block: as for the TrueTrac not providing 100% lock-up, thats fine for nearly 95% of all driving. Unless you're doing some serious off roading or drag gracing, theres no need for a full locking diff. If you need that amount of traction, I'd suggest a Powertrax No Slip diff.
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The TrueTrac isn't a full locking LSD, so when you burnout one tire may spin more than the other. Other than that the TrueTrac is good for you. A full locking diff like a Powertrax will have both wheels locked together until you go round a turn for the best possible traction.

 

The Trutrac will sometimes allow one wheel to spin and the other will not spin at all. You have to play with the brakes to get both to spin. This usually happens when doing water burnouts. If you are going road racing then the Trutrac would be great. For drag racing and most street use I recommend the Eaton. If you want the Eaton to lock up better then I rcommend replacing the carbon fiber clutches with the 18 disc steel clutches and use the 400 pound preload springs that come with it. For drag racing only you could go with the 22 disc steel clutches and 800 pound springs, but this is not for street use.

You must have a standard differentil case to use the Power Trax. If you have a standard differential and you have been doing one wheel burnouts then you may have damaged the case and the Power Trax will not work. When the case is worn it allows too much clearance between the drivers and couplers, which keeps them from locking. Many times the car will not even move, but you will hear a lot of noise from the rear end. A Power Trax requires a good standard differential case to work properly.

Wear on case behind axle gears from doing one wheell burnouts.

 

So from what I have gathered the Eaton would probably be the best for what I'm looking for. I want both tires to lock up so I can do some mad dounuts. Where can you buy the steel clutch plates???

 

You can get the steel clutches just about anywhere that you can get the Eaton posi. The clutches are also made by Eaton. Be sure that you get the shims with the clutches so that you can set the clutch preload. This is what was used in the '65 to '72 Chevy 12 bolt rear ends. They used the Eaton posi with the 18 disc steel plates and 200 pound springs. The new Eaton comes with the carbon fiber clutch plates and 400 pound springs. The steel clutches with 400 pound springs will lock up very well.