Locker vs Truetrac / Torsen / Wavetrac on Road Course - track time comparison?

[Ron Sutton]

Ron, I bought my locker from Eaton about 8-10 years ago and wondering what it would have in it? Is not quite obnoxious, but certainly very clunky and jerky at low speeds. Makes the car push under acceleration also, but there could be multiple factors there as well. LoL! What would it need for an "all around" car? Drag, auto-x, street and a tiny bit of road course sprinkled in?

Hi Jimmy,

It came new with 78# springs. AutoX is the hardest, so the 40# would be best. The 40# will work great on the street & road courses. For drags, it almost doesn't matter, because the locker stays locked in anything that resembles a straight line.

[hectore3]

Great post. And thank you for sharing your knowledge. I'm looking to replace my old 8.2 inch rear and would have joined the Tru-Trac band wagon unless I had these kinds of options in a locker regarding springs.

[Ron Sutton]

Great post. And thank you for sharing your knowledge. I'm looking to replace my old 8.2 inch rear and would have joined the Tru-Trac band wagon unless I had these kinds of options in a locker regarding springs.

Unfortunately, the lockers for C-clip rear ends will still bang & clunk pretty hard. The softer spring just makes it unlock easier. The locker would be my recommendation if you're beating on your car pretty hard in AutoX events & track days. But for more street use, the Tru-Trac is probably the best route.

[shmoov69]

Thanks Ron!!

[riles]

Hey Ron, PM sent.

[Nicks67GTO]

I'm late but I thought I would chime in. I swapped from a Locker to a Trutrac last year. Just based on the street performance, I will never go back. Both lockers I've had were loud, clunky and really raw. The trutrac is smooth, quiet and lays 2 straight black patches. Lockers are indestructible but at a price.

[Neil B]

Unfortunately, the lockers for C-clip rear ends will still bang & clunk pretty hard. The softer spring just makes it unlock easier. The locker would be my recommendation if you're beating on your car pretty hard in AutoX events & track days. But for more street use, the Tru-Trac is probably the best route.

I ran a Ford 8.8 TracTech C-Locker in my Mustang race car for several seasons. It made some noise but worked great. It did cause the car to corner with more slip angle/ yaw rate through fast sweepers but you get used to it.

[Nothingface5384]

I'm late but I thought I would chime in. I swapped from a Locker to a Trutrac last year. Just based on the street performance, I will never go back. Both lockers I've had were loud, clunky and really raw. The trutrac is smooth, quiet and lays 2 straight black patches. Lockers are indestructible but at a price.

I dont care for mine when theirs limited traction(road debris, rain) as it acts like a worn out posi..or open for a good couple feet then locks

I think the reason was the tru trac doesnt have any built in pre load
While others like wave trac, platinum track and S trac have built in pre load and or adjustable preload to combat the issies ive dealth with on my 8.5 trutrac rear..

If i would of known about the softer springs for the eaton/detroit locker id gone that route from the beginning

HEY RON,
Would these softer springs also work in the grizzly locker too?
Planning to go with either a 25lb or 40lb spring
Street car thatll see autox a couple times a month

And when I last ive researched on the torsen bia sensing units was
S trac is strongest (ford 9 version stronger then s60 version)
Wave trac next..but skip if you have full floater kit or if its going in a ford(axle shortning pass 9/16' and being weaker in fords)

Never knew where Platnium track fell in the ranks..but its preload is adjustable and you can buy rebuild kits

Then tru trac (weaker in ford)

So 8.5 tru trac
12 bolt wave trac
9in Strac
D60/S60 Strac

Or eaton locker in all with a 25 or 40lbs spring

[Ron Sutton]

I dont care for mine when theirs limited traction(road debris, rain) as it acts like a worn out posi..or open for a good couple feet then locks

I think the reason was the tru trac doesnt have any built in pre load
While others like wave trac, platinum track and S trac have built in pre load and or adjustable preload to combat the issies ive dealth with on my 8.5 trutrac rear..

If i would of known about the softer springs for the eaton/detroit locker id gone that route from the beginning

HEY RON,
Would these softer springs also work in the grizzly locker too?
Planning to go with either a 25lb or 40lb spring
Street car thatll see autox a couple times a month

And when I last ive researched on the torsen bia sensing units was
S trac is strongest (ford 9 version stronger then s60 version)
Wave trac next..but skip if you have full floater kit or if its going in a ford(axle shortning and being weaker in fords)

Never knew where Platnium track fell in the ranks..but its preload is adjustable and you can buy rebuild kits

Then tru trac

So 8.5 tru trac
12 bolt wave trac
9in Strac
D60/S60 Strac

Or eaton locker in all with a 25 or 40lbs spring

I'm not sure if the Yukon Grizzly locker uses the same springs as the Detroit locker. It probably does ... but I do not know for sure. I suggest you call Yukon & ask them if their internal springs are the same dimensions as the Detroit Locker springs. While you're at it ... ask them what spring rate is standard.

On rates, I don't recommend the 25#. The 40# is ideal for street tires & autocross.

[Nothingface5384]

I'm not sure if the Yukon Grizzly locker uses the same springs as the Detroit locker. It probably does ... but I do not know for sure. I suggest you call Yukon & ask them if their internal springs are the same dimensions as the Detroit Locker springs. While you're at it ... ask them what spring rate is standard.

On rates, I don't recommend the 25#. The 40# is ideal for street tires & autocross.

According to the one guy ive talked to, and the guy he asked said it wasnt the same as the detroit. Neither of them knew what the factory spring rate was, nor was there an engineer around.

Take that as you will
Ive emailed them prior ..around the last posting no response

[UMI Tech]

We just tried a Detroit Locker in our G-body. It took me about two tries to get used to it. Now I don't want to ever use anything else.

Our car still has the tiny explosion-prone 7.5" axle in it so the 40# springs don't fit in there physically. Eaton wasn't able to provide too much tech on the factory springs because they said, "we don't sell many of the little one". Based on my non-scientific approach on the lift, it seems the 7.5" disengages easily and the results were as such on the track. Entry and roll-through felt awesome like "coasting". On power application it immediately locked and had awesome forward drive. Love it.

We'll drain the lube and put Redline Shockproof in for the next event.

ramey

[84svoracer]

HEY RON,

Would a locker still be a reasonable choice for a smaller/lighter car when seeking consistency, durability, and stability (assuming driving style is adapted properly)? If so would you tone down the spring rates?

My car is a first generation RX7 with a mildly modded 5.0 at ~ 2,500 pounds and 50/50 weight distribution. It's somewhat similar to a fatter shelby cobra or miata but with a slightly longer wheelbase at 95". I'll primarily be doing track days, however some autocross events as well.

[Ron Sutton]

HEY RON,

Would a locker still be a reasonable choice for a smaller/lighter car when seeking consistency, durability, and stability (assuming driving style is adapted properly)? If so would you tone down the spring rates?

My car is a first generation RX7 with a mildly modded 5.0 at ~ 2,500 pounds and 50/50 weight distribution. It's somewhat similar to a fatter shelby cobra or miata but with a slightly longer wheelbase at 95". I'll primarily be doing track days, however some autocross events as well.

Just got back from Vacation.

The spring rate needed in the locker to insure it disengages on corner entry is affected by car weight & tire grip (so size & compound) ... plus the suspension setup to a lesser degree.

I can't say if it is a "reasonable choice" or not. That's too subjective. I can say as long as you have 8" of slick or 9" or good street tire, 40# locker springs will work good to insure the locker disengages properly on corner entry.

I am confident it will work well. Whether you'll like it or not is personal preference.

[nokones]

I am using an Eaton Trutrac in my 89 Corvette. So far, no problems, and the posi does a great job with the quick transitions in the slaloms. I know the IRS suspension is different than a straight axle and I am not hiking up the inside rear tire like a straight axle would but, I would definitely put one in a straight axle diff. even with a lot of horsepower.

[84svoracer]

Just got back from Vacation.

The spring rate needed in the locker to insure it disengages on corner entry is affected by car weight & tire grip (so size & compound) ... plus the suspension setup to a lesser degree.

I can't say if it is a "reasonable choice" or not. That's too subjective. I can say as long as you have 8" of slick or 9" or good street tire, 40# locker springs will work good to insure the locker disengages properly on corner entry.

I am confident it will work well. Whether you'll like it or not is personal preference.

Thanks for your input. I've driven a few cars with lockers and see no huge problems driving technique can't overcome. What I like best is they work, and generally don't break or need any maintenance.

My main concern is that the wheel wells on my car aren't exactly large, especially in the front, so I'Ll probably just be running 205/50/15 200 TW aggressive street tires (Hankook RS4) which will put me closer 8" tread width range (I'm running forged wheels that are only 6.5" wide as well). I want to avoid running staggered front/rear tire setup even if its a bit faster as I'd rather invest that into track/driver time and to be able to rotate my tires for a little better tread life. Given this, would you still consider a 40# spring, or would a 25# spring for better locker disengagement be advisable with less tire?

[Ron Sutton]

Thanks for your input. I've driven a few cars with lockers and see no huge problems driving technique can't overcome. What I like best is they work, and generally don't break or need any maintenance.

My main concern is that the wheel wells on my car aren't exactly large, especially in the front, so I'Ll probably just be running 205/50/15 200 TW aggressive street tires (Hankook RS4) which will put me closer 8" tread width range (I'm running forged wheels that are only 6.5" wide as well). I want to avoid running staggered front/rear tire setup even if its a bit faster as I'd rather invest that into track/driver time and to be able to rotate my tires for a little better tread life. Given this, would you still consider a 40# spring, or would a 25# spring for better locker disengagement be advisable with less tire?

Frankly I don't know. That 205 seems pretty narrow. A 40# spring may work fine or it may be a tad bit too tight. Unfortunately, there are no more 25# springs available to test. They were used for dirt ovals only & not very popular, so we stopped having them made.

I hate to say this, but the only way you're going to know if the 40# will work well with your 205's is to test it ... if you're willing.

[84svoracer]

I'm certainly willing to test it. Worst case scenario is rolling the fenders more and picking up wider wheels to run 225's, so certainly not the end of the world Thanks again for the advice.