Best limited slip diff for a Dana 60

[Hemi Steve]

Hi
Need some advice. I have a 73 Cuda with a 528 Hemi cross ram, T56 6-speed going to a Dana 60 with a Detroit Locker with 3.73 gears. I bought the car this way and thought I could learn to love the locker. I've driven it for a year and really don't like the locker. This spring I'm going to pull it out and put a limited slip in.

What is the consensus on a diff for this setup?

Steve

 

[aussiemark]

Maybe try the original clutch style unit Chrysler used as original equipment it will be a lot more friendly for the street then the Detroit Locker and if you don't like it you can always put the locker back in.

 

[Hemi Steve]

What Chrysler unit fits the Dana 60 housing with 35 spline axles?

 

[70Hardtop]

Steve, I have had very good reports about the Dana Trac-Loc, (Dana Spicer unit), and I spoke to a guy that was not happy with an Eaton TrueTrac in his Barracuda (too noisy on coast and too much lateral wheel play) so he replaced the whole axle assy with a Dana 60 and put in a new Dana Spicer Trac Loc. He said it is streets ahead of the Eaton in terms of noise.

BTW, it is a 35 spline LSD unit, made by Dana, so you know it will work.

Hope that is good advice for you.

Dana Spicer Trac-Lok Limited Slip Assembly - Differentials - Performance Axle Components - Drivetrain & Differential - by Trans American Wholesale

 

[Hemi Steve]

70Hardtop
Thanks for the response. I'm aware of that LSD but according to Doctor Diff the Trac Loc is good for up to 400hp. My hemi puts out 670hp at the flywheel. I don't know what the rear wheel hp is Dana 60 "Trac-Lok" Differential

They also show a Sure-grip clutch type unit but don't say anything about how much power they can handle. Dana 60 Clutch Type Sure-Grip ("Powr-lok")

Can't find real experiences with these LSD units in relatively high hp applications.

Your thoughts on Sure-Grip?

Steve

 

[Steve340]

With that kind of power no LSD will be bullet proof if you really give it a hard time. I have been in cars with the detroit locker and I agree with you they are not street friendly for most people.
However with that much grunt you just have to factor in maintenance of the rear axle.
How much you have to do will depend on how hard you beat it.
Most likely the rear tyres will act as traction limiters. Manual transmission cars are harder on the drive line than an automatic.
Most LSD units are OK from what I have seen until the owner bolts on a set of sticky tyres to go drag racing.

 

[Hemi Steve]

The big issue with the locker is slowly backing out of my garage while having to turn sharply or trying to slowly back into a parking spot and turning sharply at a cruise night. Forward sharp turns at walking speed has the same issue. The clicking in normal corners is annoying but I can deal with it.

You are right that the tires are a torque limiting device off of the line but eventually the car will hook up and then at some rpm the diff has to transmit the full engine torque.

Am I over thinking this?

Steve

 

[Steve340]

Essentially the locker is trying to make both wheels turn the same speed.
You are going to notice it as you turn. I dare say it is OK in a straight line on a highway.
Long story but an opener wheeler will let the wheels speed up as they rotate through a different arc without noise. It is doing what it was designed to do.
I don't think you are over thinking it as you said the noise gets annoying.
The thing you have to decide is it annoying enough to change.
The detroit is doing its job and that won't change.

 

[aussiemark]

What Chrysler unit fits the Dana 60 housing with 35 spline axles?

I was also referring to the spicer trac-loc clutch style lsd as used by Strange Engineering as an option in their complete assemblies. These are the same design as the OEM and are more suitable for street use then a Detroit Locker and they suit 35 spline axles which are the std ones from strange with 40 splines optional. I would have thought any Dana 60 components would cope with more then 400hp, a std 440 six pack has 390 under rated hp even a Chev 10 bolt should be good for 400hp and they are not as strong as a 8 3/4 Chrysler diff.

 

[JoesEdge]

Hi
Need some advice. I have a 73 Cuda with a 528 Hemi cross ram, T56 6-speed going to a Dana 60 with a Detroit Locker with 3.73 gears. I bought the car this way and thought I could learn to love the locker. I've driven it for a year and really don't like the locker. This spring I'm going to pull it out and put a limited slip in.

What is the consensus on a diff for this setup?

Steve

So only for a year? I drove a small pickup truck with a detroit locker, 33" tires, pretty much built for off-road. I put over 100k miles on that locker. I had that truck for about 13 years. I sold it with over 200k miles and it still ran decently well. I just needed something bigger. Anyway... Other than the bangs the diff would make when it would lock up, I loved the hell out of that locker and I am considering putting in my 8 3/4!!

Give it some more time. That locker is near bullet proof and you know you will have traction for sure. The only time mine annoyed me was through fast food drive through because of the sharp corners, but that's when you learn to drive it. Give the car a little launch, push the clutch and coast through the turn. Worked every single time! Same deal with cruises. Same with making right turns too.

I feel manuals and lockers go well together because you can just push the clutch and the locker should unlock, but get ready for the bang when you get back on the throttle. You get used to it. The benefits are worth it.

Only only reason why I am not switching to a locker today, is because my 19 year old son that uses the car as a daily driver and isn't experienced enough with the 4 speed to know how to handle a locker. It just takes experience. You'll get it with more time.

 

[Hemi Steve]

JoesEdge
Thanks for the input. I understand the concept of using the clutch to try to coast in a tight turn in order to get the locker to unlock. My beef with my locker is in backing into or out of tight spaces where you really can't get a little speed up before pushing in the clutch to get the locker to release. It takes a fair amount of force to overcome the locking springs and unlock the locker. At creeping speed as soon as I start to turn with the locker engaged the car acts like the brakes are being applied which then requires that I apply power to keep moving and that just serves to keep the thing locked. If I push in the clutch while turning at creeping speed, the tires are scrubbing on a high traction surface and quickly slows the car to a stop without unlocking the diff.

Your tall tires probably help a lot in getting the diff to unlock. The tires on my 'Cuda are 26" tall.

As I think about this more, I think a clutch type LSD could exhibit the same kind of problem depending on how tight the clutches are. The Truetrac helical gear type is an unknown in this kind of creeping speed tight turning. I've read posts elsewhere that are conflicting on whether creeping tight turns are or are not a problem with a Truetrac. Is there anyone reading this who has actual experience with a Truetrac in this kind of maneuvering?


Steve

 

[Steve340]

I had a Truetrac in my car and found it very good. I found that creeping forward at just off idle you could get little clunks as it locked or unlocked. I am talking about fast walking pace. I also have an original Sure Grip in my Challenger and it will do the same while it creeps forward with that cammy surge thing going on.
However I never noticed anything with either diff turning sharply. In general silent operation.
A few revs to get the engines out of the cammy zone and slipping the clutch a bit to get smooth take up and no problem with noises or clunks.
I would go out on a limb and suggest you try a Truetrac. No LSD oil or additives required just straight gear oil. Myself and several friends have never had any trouble.
Clean the housing and axles thoroughly as the friction modifiers in LSD oil may upset the operation of the Truetrac.
I believe the Truetrac has been copied I purchased mine off Summit and made sure it was in an Eaton box.

 

[Hemi Steve]

Steve340
Regarding sharp turning....noise is not of much concern to me but locking up or remaining locked and scrubbing or squealing the tires or feeling like the brakes are applied as I back up (for example while turning sharply as I turn out of my garage) is my issue with my current locker. Are you saying that you don't have that behavior with your Truetrac?

Steve

 

[Steve340]

Correct I have never noticed and locking or scrubbing of tyres at low speed in tight turns.
The locker is not letting the tyres rotate at different speeds.
However a very large engine like yours may have enough torque slightly lock the diff.
Not 100 % sure with your situation.
Small block cars I had no issue and I am certain the improvement will be significant compared to the locker.

 

[Hemi Steve]

I think that at creeping speed the size of an engine is not in play as it's operating just above idle and slipping the clutch as well.

Thanks for the real life experience with the Truetrac diff. Sounds like it will be the right thing for my car.

 

[Steve340]

Yes I think you would be happier. I found the Truetrac behaved like an open wheeler most of the time and if you got on the gas it left 2 black stripes.
The guy who fitted the unit for me said they were originally designed for rock crawlers.
Are your rear tyres exactly the same size and make.
Very even in tread wear?
These are factors which can affect a diff unit even an open diff.

 

[Hemi Steve]

Reviving this thread. I'm all set to get the Truetrac for my Dana 60 but of course I need to know the spline count. This afternoon I pulled an axle shaft and was shocked to find that they are 23 spline. I'm totally confused now.

I also discovered that the drive axle is not an actual Dana 60. It is an aftermarket unit...Strange or Moser or?? Why do I believe this?
1. It has the cover bolt pattern of a Dana 60
2. It is pristine. No evidence of any prior rust on the tubes or housing
3. There are no stamped date codes or BOM numbers on the right tube which a Dana would have.
4. The Dana housing would have the numerals "60" cast into the lower right reinforcing web and this axle does not have that marking.

These 23 spline axle shafts are big. My calibrated eyballs says they are 1-1/2" diameter

My previous 70 Hemi Challenger had a Strange axle and it had no markings.

This Cuda drives like it has a locker but I cannot find any locker, spool, limited slip or open differential that will go in a Dana 60 style unit with 23 spline axle shafts.

Does anyone have an idea of what this is??

Steve