Spool, truetrac, clutch sure grip or other for street/strip?

I have a new Auburn unit in the car (complete 3rd member from Manciniracing) that's already starting to make noises going around corners. Less than 2k miles.

It's in an 8 3/4 with 3.55 gears and I'm pushing 600 horsepower with ET Street Pro's.

I'm not a fan of the Detroit locker because of the noises it makes in a friend's 9 inch.

I've thought about a spool but not excited about corners on the street with one.

Is the truetrac okay for this level of horsepower and sticky tires?

I've started gathering Dana 60 parts and may just upgrade the whole rear.

You want it all and the cake too? You can't have it. They make lockers that aren't as noises around corners.

You need a locker or a spool.

I have a S60 with locker , don't even know its there

Tex

Love my spool for many years..........

No Eaton true trac in an 83/4 they are JUNK !! the axle side gears move all around & dont support the axle end & makes all kinds of noise when slowing down. I have so much time & money in this crappy 8 3/4 NEVER AGAIN,,, Dana 60 is the only way to go.

check this link link to true junk

What about some sort of air locker like that use for offroad setups. ??

I have a spool, I was really worried about it before I put it in. But once I got it in the car it's really zero issue.

3.55 gear with 275 drag radials.

This drive around video shows the car turning around a tight corner (7min mark). No binding , no sqeeling, no problems.

https://youtu.be/vqJoG_2wdMQ

Just respect the car in the corners before you're on the throttle hard and you won't even notice.

Keep an eye when in wet weather conditions with a spool. Get good axles and bearings along with good seals.
Also, the best man for the job with which ever way you go is no other than Dr. Diff.

I am running a borrowed 9 in. center section since I broke mine and it has 4.56 gears with welded spider gears (Poor mans spool). It works great and does not make any noise when street driving.

I have 3.54 Dana gears, housing ends to weld on in place of the full floaters and a truck housing. Looks like I need to ring Dr. Diff and get axles, bearings and a spool...

I have been running Detroit Locker for over 5 years and I love it. Most of the time I dont even know its in there. Ron

Another Detroit here, can't say I've heard it making much noise on corners, it's way more friendly than the spool I had in it before.

Spool here, no issues in the six years I've had it.

With my old 8.75, the Auburn sg didn't hold up; the clutch-type sg was the better option.

When I ordered my Strange S-60 from Doctor Diff, we discussed both the Detroit locker and Strange's S-Trac. I ended up going with the S-Trac. Strange has a video on YouTube that goes into the details of the S-Trac that I found helpful, too.

Ditto on this. The key to the Locker is knowing what RPM to shift during street driving, turns etc. Once you find what it likes, you wont notice it.

a "lincoln locker".

I have had a spool in my car for a long time. I had an auburn unit at one time that didn't last long at all so the spool was the next most reliable choice when I moved to 35 spline axles. My Jeep has a locker in it and while its better than a spool it is still a spool anytime your under throttle. It still chirps and barks the tires around corners and it can swap ends on you in the rain if your not careful when it goes from "open" to locked around a corner. The spool is really only annoying in parking lots and spaces that require tight turning, out on the road its a non issue.

I've had a spool in my cuda for about 15 years, street and strip, no problems ever. Dry pavement, wet pavemet, doesn't matter. The issues some people blame on a spool ends up being from the tires they were running.

Auburn type units are garbage, but you know that .

A true trac COULD hold up to that power but you need to disassemble it when you get it and make sure it's put together properly, the one I put in a friends 8.8 was not and ate itself up in less than 15k miles with maybe 100 passes.

He ended up going with a Yukon Grizzly locker that I changed the springs to lighter ones to make it more street friendly. The last time I was in it you could barely hear it making the clicking that it does when going around a corner.

He isn't making the HP you are, '12 V6 mustang with a 50HP shot that runs in a 12.50 index class with slicks and a manual trans.

"Auburn type units are garbage, but you know that"

I unfortunately have come to that conclusion, AFTER I bought a new Auburn, my question, is there any low enough hp application that an Auburn will survive, like a healthy slant six?

Take it apart, use a spring tester and find out what the factory springs are and replace them with some that are 200lb. stronger. There is also a video out there that tells about taking the cones out and machining the flat on the small end off so that they cannot bottom out in the housing. By doing the stronger springs and the machine work, the Auburn can work like it is really supposed to.

An Auburn will survive if you NEVER turn ...

All that does is continue with it's pisspoor design , they self destruct everytime you turn.

And that is only doable on the Borg Warner cone type , and don't forget to shim the side gears after machining the cones. the current design Auburns are not designed to be disassembled , once its not working anymore it's a door stop.

I've been making really wide turns lately to prolong it's life until the Dana is done.

But I really like my steering wheel

Go the Dana path, I to spent many $$$ on eatons trutrac in an 83/4 but the noise was just beyond belief, now have a Dana truck, with ends, axles from Cass, Strange S-Trac and 3.7 gears,,,,, much happier

I have a locker in my car with a Dana 60 and I absolutely hate it. I hear people talk how great they are and I just don't get it... Run a spool before you run a locker. At least it won't crack and bang lol. I ordered a S60 from Cass with the strange differential he talked me into. I hope it works good.

I have a spool for the Demon. The Grand Wagoneer has a Lockrite locker and it clicks all the time when turning, but it locks up right now when in the throttle.

I have a Power Trax (VX-124A) locker in my Cuda's 8-3/4. It has seen a fair amount of track use since the year 2000. It does click when making turns, but I am OK with that. It came with two sets of springs; one stiffer for more track use, and one set for more street use. This car is over 3700 lbs with me in it and runs high 11's in the 1/4 mile.

Dont know what kind of locker you have but I run the Detroit Locker in my 8-3/4 and most of the time I dont even know its in there. Sure a little click now and then but thats all I ever notice. I hardly ever here noise from my locker that I can hear and I run a full exh out to the back of the car as my car is not all that loud. But with the Dana why not just run the factory posi/sure grip clutch pack setup ? We ran that for years in my brothers race car.
Is the Strange diff you are getting a clutch type unit ? Ron

Its a Detroit locker if I remember. There's no doubt it works. Its just WAY too harsh for my car and setup. It is going to break something in the front end of my car if I continue to use it without a doubt. It probably has real heavy springs in it im sure. I ordered a s60 with the s- trac helical differential from Dr. Diff.

Still have the spool that came in the car when I bought it over 25 years ago

You'll love it! I just changed from a true track to an S-tack and you can't even hear or feel it.

I just looked at the S-track .pdf and it looks like a just Eaton True Track but with a THRUST PLATE in the center.

You guys are making me lean towards a spool for my street car. I ran a spool in all my cars over the years because they were also raced alot. The spools were ok but tend to be annoying when turning in a parking lot or if you are trying to push your car around in a driveway if the motor isn't done yet, it is almost impossible to push the car with the front wheels turned.
But, I have a Duster with a stroked big block and if I decide to drive it to one of our local dragstrips and make a few fun passes, I'd have zero confidence in my cone-type factory posi unit(8.75). A spool with some 3.23 gears and some drag radials might have to be the way to go.

Cass told me I will really like the s-trac. Said its good for 1,000 HP. I'll never be at that kind of HP and my car is a street car and want it to have decent manners. I have done some reading on them and it sounds like they take quite the abuse on pretty fast, high HP cars on the track.

I ran a locker for a few years. It wasn't loud or anything, and it stood up to my abuse. Only thing I didn't like was that it pushed the car left & right when on & off the throttle. Wasn't really a big deal, until I started doing more bracket racing, and suddenly racing the stripe became an adventure when the car wanted to dart around at 115mph when I chopped the throttle.

I went to a spool this past winter, and I really can't figure out why people make a big deal out if it. Knowing what I know now, I'd choose a spool over the locker for a street / strip car. Sure the inside tire chatters on tight slow corners..... big deal.

I would put in a Detroit locker before a spool , if your exhaust is loud enough I doubt you'll here the clicking going around a corner.

Strange only makes the S-track for the Dana 60 and 9 inch so it's not an option.

I had the cone style in my 8 3/4.. it lasted 600+
passes... but I spent a whole day(maybe more) lapping
in the cones so they were perfect.. both tires hooked
the same until the caps blew off.. then I changed to the
alum center with a spool.. I drove a spool on the street
for more than 5 years during the summer

Its funny as I hear some say that about their Lockers but I have never had that happen with mine. It always stays straight and true on or off the gas in the traps. My exhaust is not real loud but I never hear much of the clicking. But a little electric fuel pump noise dont bother me either and I see alot complain about that also. I grew up with hearing the electric pump when the key was turned on as you knew it was working that way and it is a muscle car/hotrod so a little noise dont phase me any. But honestly I have never felt the side to side pull when on and off the throttle in the traps or anytime for that matter. Guess thats why I like my Detroit Locker so much and dont want to run a spool on the street. Course many have their prefrences and you have to use what you like. Ron

To try and simplify this "many times" kicked around subject. Most streetable to least streetable = cone type, clutch type, locker type, spool. Just the opposite for the track. Mr Norms test; run the car up against a post, jack up one rear wheel, dump it in gear and stand on the gas peddle. If you can smoke the rear tire that is on the ground, the posi unit is good. Guess it was faster and cheaper than the torque wrench test. You have to come up with your own definition of streetable. All performance cars of the 60's / 70's came from the factory with clutch style units. They worked fine on the street in the 3 - 400 HP range. On the track with large slicks and another 100 HP added, They're life span was cut in half.

Spool: hated it on the street.
Detroit Locker: Put one in my 00 Silverado, love it on the street & mud/snow.
cone/clutch factory suregrip.. was great till I hooked real hard one day lol.

As I'm sure you've noticed, Ron; it seems that everyone with a locker has a different experience. I agree with you that it wasn't a neusance at all on the street as some people describe. I never heard any clicking sounds or anything like that. I would have stuck with it if it wasn't for the L/R pushing thing. Plus I wanted to go to 35-spline axles.

A locker and spool need rear tires to be swapped side to side regularly. ANY stagger in rear tire diameter with be noticed.

I am sure if I felt mine doing the pushing from side to side I would not like my Locker either. I agree many feel different about them as we can tell just by this thread. You have to go with what you feel good with. Ron

hi johnrr,so is the true-trac another door stop like the cone-clutch? boy... a lot of door stops around. ronnie

The one I have here of of the 8.8 is a door stop , your welcome to come as see the damage for yourself if you think otherwise.

The true track is probably fine if it's assembled correctly , it appears the one I have here was not, I never opened it up to begin with.


As far as any CONE type goes ... pure and utter GARBAGE , it's designed to fail.

the true trac for the 8 3/4 is a DOOR stop, they say the one for dana is ok.

When a car (ANY car) makes a left or right hand turn, the outside wheel HAS TO rotate faster than the inside wheel, in order to maintain traction at both wheels. The tighter the turn radius, the faster the outside wheel must turn in relation to the inside wheel. Obviously, a spool does not allow that to happen, so something has to give, which usually means the inside tire slips as you negotiate the turn. That's what's happens to ANY car with a spool, and your back tires will wear out faster because of it.

Pretty sure everyone understands that Dave. Wearing tires out faster is not one of the things most people complain about a spool causing...and not what I was referring to.

hi john, yes I want to see this junk firsthand .pm me you are full. ronnie

Anyone use the $395 Power-lock from DoctorDiff?

http://www.doctordiff.com/8-3-4-clutch-type-sure-grip-powr-lok.html

hi pro, Doctor Diff recommended and sold me the clutch style until they get the bugs out of the 8.75 trac-lock. cass thought by xmas 2016 or jan 2017 that trac lock would do the modifications needed to work properly on the mopar 8.75 . its time to call him and ask about updated mods on trac lock. the doc's powerlok works perfect and is a moparts recommend from me. ronnie

My diff is soon being put together and I was told TrueTrac was the way to go lol. Geez
3000 pounds, 650hp, big tires. Street car
Has anybody tried the SureTrac that Dr Diff has on his site?
The rear end guy suggested Auburn Pro or Eaton TrueTrac, said he didn't think a power locker would hold up....
It's the MP aluminum case if it matters....

True trac here in a dana60 for the past 12 years. About 100 track passes on it and around 5000 street/highway miles. Heavy stickshift b-body. 3900 lbs at 620 hp. No problems for me with it ever.

Funny, this thread is 4 years old!

What I ended up doing was going to a Dana 60 with a Dr. Diff spool and axles. I couldn't be happier!

This car sees a lot of street miles and gets to the track probably 5-6 times during the Summer. Only issues are with tight parking spaces but I can live with that.

I'm now spraying a 200 shot on top of what I was doing and everything works great!

The only thing I will recommend is throwing the wheel studs that come with the Dr. Diff axles in the trash and replacing with something like Strange. They were bending.

I did the search function to see what was said on the TrueTrac lol
Not sure if the quality issues with the TrueTrac were ever fixed over the years but I see Dr Diff said on his site he doesn't sell anymore because of inconsistent quality issues.
I see the SureTrac he recommends looking at too.
It's an 8 3/4, I want to TRY to keep it 8 3/4, heavily back braced, load bolts to the caps, aluminum housing, 2900 pounds or thereabouts, 650hp, 650 ftlbs, foot brake, street tires, bushed four link. I am leaning towards 3.91 Richmond/Motive gears. 30 spline Dutchmman axles. I don't want to run a spool, not sure what is out there in 2020 I guess, lockers, or? Torsen?

Of everything i have had, locker was easily the worst
When you got out of the gas on the street at high speed, car behaved scary
No such issues with Posi or spool
Never again with locker

I have the Strange S-trac S60 I got from Cass, it works AWESOME !!!

I ended up going with a Moser dana 60 with a spool in the Demon. I live 1 hour south of them and picked it up at their dock. Complete minus brakes, powder coated, 35 spline axles and 4.10 gears $2760

I have the same set up from Dr Diff in my Savoy . How are your wheel studs bending?

The ONLY time I've not wanted a spool is when trying to push the car w/ the front wheels turned.

Spool Guys:

Just wondering if you have wide tires or "normal" width, I'm wondering how the rear tire width
with a spool affects drivability. I'm looking at doing one car with 18.50 tires.

I ran a spool with 18.5 tires on the street for awhile. It wasn't bad. I switched to a locker, but a spool will work.

Love my s trac

Big torque and crap quality studs that weren't Grade 8 like they were marked.

No doubt! A couple of degrees of steering angle and you're screwed! One of the tracks we go to has a 90* right turn in the staging lanes and then another to get to the burnout box. It gets fired up to move it.

What is the practical experience with the warning from the Strange S-trac manual:

From a traction perspective that’s exactly what we want a differential traction device to prevent!!!

In my 8.75 I just swapped from a 2.76 single track to a 3.23 suregrip. It was/is only there until I get around to pulling it and swapping in my freshly built 3.91 spool rear. I run an B engined Demon it mostly sees and will continue to see street duty with some racing here and there. I'm hoping at least a stage or two of Drag Week is in that mix this year.

When I build my 512 I may swap to a 60 based rear.

Should I assume the Eaton TrueTrac is still hit and miss and to be avoided?
Powerlocker- anybody have good/bad stuff I should know? lol There has been a powerlocker in the car for years and years, I've never had trouble with it....
I know....
Yet lol

I ran a spool years ago in my bracket car and loved it for a race car. The one thing I don't like about them is if you have to have the car pushed as then it feels like you put the brakes on when turning. That's why I went with the Detroit Locker for my street car. And its been working fine for about 9 years. Ron

I have a Detroit Locker in the Duster but I'm going to swap it for an S Trac. The Locker is noisy and sometimes it does something weird when I'm not expecting it. Nothing super serious, just a wiggle when I get out of the throttle or something like that. Can be a little spooky if you're coming around a corner or going fast.

Andy how does the S Trac work ? Is it a posi type of unit ? Thanks , Ron

We have a Detroit locker in our Dana 60 in a 3900lb (W/D) E body. It works really well, no noises, no shimmy when on and off the throttle. I phoned round looking for something to take 950ft/lb and 1000hp + and no-one would recommend anything but a spool we have little room to turn round where we live so a spool was a no Couldn't be happier really, car goes straight and will carry the wheels 100ft+ on most passes

Spool in my car was in there when I bought it 30 years ago. Street driven over 1500 miles a season and an average of 50 passes per season.As of now the car has been 9.3 @ 147 ,,,,,,,,,3700 lbs.

OH,,,,,,,and BLACK LINES MATTER for those with Carownersvirus

nice lines -itis !

i did that one time, and my buddy gathered up all the smoking dust particles and rolled them into a bigger than golf ball size ball of rubber. i still have that thing somewhere........

This thread has been enlightening. I have always read to stay away from a spool if the car is street driven. I am seeing now that may not be the case. How about in a light rain, does a spool make the car step out in a turn?

Hell yes. Requires pretty careful application of the throttle in any turn on a slick surface! Roundabouts get really interesting.

I do my best NOT to get caught in the rain. My tires have no tread! I have a couple of times when it sprinkled and just had to drive slowly and carefully.

No it doesn't! My first trip to the track w/ a spool installed, it rained on the way home...I drove the car there. I was worried b/c of everything I'd read on the internet about spools, but it didn't act any different at all. That was on normal radial tires.
The tires have everything to do w/ how the car acts in the rain, not the spool. Driving on ET Streets in wet weather isn't a good idea. On normal tires it's no problem.
If you spin out in a curve w/ a spool, your right foot was the problem.

This is a very informative thread, should be archived imo. Any way, one aspect I've seen neglected here is cost, a spool being in the $150 range vs a Detroit locker in the $725 range for a Dana 60. I've been weighing the pros and cons of upgrading my 8.75 vs biting the bullet and going the S60 route. The S60 seems to make sense to me, spend the money once, then never worry about it again. I'm gonna go spool as well, cost effective and extremely reliable. Just my 2 cents.

I agree with 8sec70cuda.
got caught in heavy rain sunday morning, spool and nito drag radials had no problem at all.

Well us on the keyboards can never be 100 certain what is the "problem" mentioned above, but it is a simple proven fact, there has to be rear tire slippage with a spool in a turn ( unless a tire lifts off the surface when turning), period. Now if on one car, with its unique suspension, its unique tires, its unique tire pressures, its unique weight bias, its unique shocks/settings, and a host of other variables too long to list, when a driver does not experience a potential spin out, I find it hard to state the spools natural turning tire slippage can always then be disregarded.

A spool is at least predictable, it will do the same thing all the time. A locker is very quirky, you might have an open diff going around the on ramp in the rain but when you apply power you get a spool when it locks, or sometimes the decel force is enough to lock it that way and that can be sketchy. My Jeep has lockers and they do weird things, you can lock and unlock it in a long turn and feel it push on the front end and drag the tire, but if its wet you have to be careful because that transition from unlocked to locked will make it step out. Same goes for a limited slip, on a slick road they can act like a spool if they are tight, they can still cause the tire to drag on the inside.

A real good & tight suregrip or locker will still be slipping that inside tire on slick/wet pavement. Never hear anyone complaining about that.
Just about every time someone starts stating these reasons a spool is dangerous, they have zero personal experience w/ them. Hear this crap a lot and when you ask how they know this...so and so told me or they read it on the internet. It's amazing how so many of us who have actually done these things we're commenting about are still here today.
If you can't drive one of these cars around a corner on wet pavement w/o crashing and blaming it on the differential, then you need to sell it and get a prius.

So some want to include the quirkiness of a locker (which I 100% agree with) and the tightness of a suregrip ( which is a rather large variable) with the discussed downsides of a spool cornering in the wet, but nobody mentions the OP's option of a Truetrac or helical gear diff, which does not have these major downsides.

I drove mine to work today.

Hopefully I make it home in one piece....

Better say a prayer before you head home, lol. Those spools are super dangerous don't ya know?

my son drove my dart to work this morning. no issues like said above don't hammer it going around corner's and drive respectful and all will be good.

All of this is good information. I am planning on upgrading my 8.75 with a Dana, I'm not afraid of a spool in the rain, but parking and pushing a heavy B body (4000lbs) is hard enough with manual steering and a tight Sure-Grip. Would a spool be that much worse?

HAHAHAHAHAA!

YES!

I expect soon replies here stating about my rights to run a spool, road race cars that seldom if ever run a spool because they turn LEFT and right, complaints about other members hoping others with spools on the road wreck, and avoiding like the plague, with huge doses of deflection of physics, as already mentioned, fact that a spool causes/promotes rear tire loss of traction in a turn, unless running stagger or lifting a wheel, and most of all, only those who are brave and got big ones drive a spool on the road in the rain, so be a man get spooled.,

Surprised anybody that survived their spool wreck, can read this in the ICU.

I have a vague memory of a locker controlled by air pressure, so it can be turned on and off from the dash. Or am I just mixing up memories?
Anyway if it exists, it doesn't seem to dominate the market. Must be a reason for that.

ARB air locker. I recall seeing them in the 4WD magazines.

Winner !!

Just put your purse down before you park and you will be ok! LOL kidding, parking lots are really the spools biggest downfall.

My Locker does not slip a tire on turns or wet roads as it unlocks one tire that just goes along for the ride when turning. Of course it locks back up when you straighten out. I have driven in the rain with my locker 3 times when I have got caught in the rain and that on my 30 x 9 slicks. I just took it easy and had no problems. I agree a posi/sure grip may slip a tire that uses a clutch pack but my locker unlocks mechanically as it dont use clutches that need to slip on turns, Ron

I installed one of these Posi units in my Dart over the winter https://www.jegs.com/i/JEGS/555/62820/10002/-1.

Seems okay to drive but its noisy when turning. Even slight turns you can hear it.

Maybe it'll break in a bit and not be so bad but It creeps me out, I wish I had just gone with a spool now.

My experience is much like 383Man's with his locker. I've had both a Detroit Locker with a manual trans and a spool with a 727 and I could live with either one just fine. The locker was behind a T56 in a 9". The only time that one behaved oddly was if you were letting off the gas in a turn (which isn't a great idea anyway). It would clunk and shimmy just a bit. With any type of reduced tread depth tire and some moisture on the road, you just need to take it easy. The locker is more expensive so that's a downside, but it's very true that the spool is absolutely no fun to push the car around when it's not running. Just my 2 cents