Detroit Truetrac Limited Slip in a Ford 9"

[d0n_3d]

I'm really trying to figure out what is going to be the best route to go with my rear end. I'm going Ford 9" setup. I've heard stay away from lockers because they are annoying on the street (locking and unlocking all the time). I've also been told not to do a spool. Is there anyone or has anyone you know used a Detroit Truetrac limited slip diff with their 9" or any rear for that matter? I see it doesn't use clutch packs, rather all gears and is maintenance free with no wearable items. They have a 31-spline version available. I'm just wondering how much power they can handle. My car will be 95% street driven with occasional trips to the track and I want it to be able to handle a high 9 second pass if needbe. Would this be a good unit?

"Detroit Truetrac was the first helical gear differential ever introduced into the automotive aftermarket. It remains the leading helical gear-type limited-slip differential in the industry. Its proven helical gear design eliminates the need for wearable parts, resulting in maintenance free traction. Recognized not only for its durability but also it's smooth and quiet operation.

Power transfer is so smooth; it literally goes unnoticed by the driver. Engineered to work efficiently in front and rear axles. No maintenance - Just Traction!"


Detroit Locker #357-913A586

# 1976-87 Ford Car/Truck Truetrac Differential 31-Spline Axles
# 9" Diameter Ring Gear
# Fits All exc. 2.72 Gear Ratios

 

[meanchicken]

I have one in my 68 Camaro's 12-bolt...and yes you can get them for 31 spline (also have those).

It's behind a ZZ502 that makes an estimated 550HP and 575TQ, and a TKO-600. I also have a 12" clutch and 12" fly wheel, so all that power is going right to the rear end and hits H-A-R-D!

Makes the car very easy to control in a power slide drift through the corners.
I love it.

I also prefer to keep a GM a GM. The Moser 12-bolt is every bit as strong as a Ford 9". The Moser casting is beefed up in all the OEM 12-bolt weak spots and you can get it built with 9" ends like mine. With a rear-end girdle, it would fit the bill even if you do build your car to get into the 9's.

IMHO the only real benefit you'd get from the 9" would be the easy gear swaps....but that's only a benefit if you actually plan on doing it.

 

[d0n_3d]

I see Eaton makes a super strength 33-spline limited slip setup for the GM 12-bolt. Definitely more pricey at $950 just for the diff. The 12-bolt housing setup is about the same price as a Ford 9 otherwise. Something to think about I guess.

 

[turbows6]

I would use an aftermarket 12 bolt too. Lighter and more efficient.

 

[UNGN]

I have a detroit locker in my Grand Prix 2+2 and it isn't that noisy on the street.

I did manage to destroy it, however and had to buy a new one.

I missed a shift at 163 mph (I put it in 4th instead of 6th) and spun the rear end backward, which will kill a locker.

So if you own a locker NEVER do a burn out or launch the car in reverse (basically, don't be an idiot like me)


Don't know how geared limited slips respond to drag racing abuse, but generally they don't like it.

 

[meanchicken]

Missing shifts at 163mph will get you on the Naughty List for sure!:biggrin:

 

[DR BOOST]

I have a detroit locker in my Grand Prix 2+2 and it isn't that noisy on the street.

I did manage to destroy it, however and had to buy a new one.

I missed a shift at 163 mph (I put it in 4th instead of 6th) and spun the rear end backward, which will kill a locker.

So if you own a locker NEVER do a burn out or launch the car in reverse (basically, don't be an idiot like me)


Don't know how geared limited slips respond to drag racing abuse, but generally they don't like it.

holy crap... ive never had a car that could hit 163 and still have another gear to shift into !

 

[d0n_3d]

holy crap... ive never had a car that could hit 163 and still have another gear to shift into !

yeah that is quite crazy........I've never driven a car faster than 135 mph let alone "shifting" at 163....guess I'm either boring or not crazy?

 

[UNGN]

It was at the big bend open road race we attend every April in west Texas. They close off 65 miles of highway. you get disqualified for going over 168 mph, but you pretty much can drive as fast as you want if you keep it below 168.

I actually thought I was taking it easy and leisurely put it into 6th for a long straight cruise at 165 mph, but it slipped into 4th and all hell broke lose (it sounded like an airplane landing on a runway). The speedometer and rally computer both stopped working from the shock.

I saw 7 grand+ on the tach before I got the clutch back in, and for the next 40 miles the locker slipped a cog every few seconds. We ended up winning the 135 mph class by shear luck and guessing our speed with the tach and the 502 never missed a beat.

My only complaint with a locker is also why people like them:you always know its there. When you get on the gas, both tires are going to go in the same direction and the same speed, if you want them to, or not.