Limited slip in a 9 inch?

I run a True Trac in my 55 and love it. Will take more abuse than a clutch type diff without being as aggressive as a locker.

 

I believe mine is a Tru-trac. Hitting second hard will break one wheel loose. Once it breaks loose the rear end "goes open" and just burns up one tire. I think you have to maintain traction with both wheels to toque split. Getting one wheel stuck in snow or mud is no good either. It will just spin.

 

Mine does not do that. The wife's doesn't either.

 

you've never looked at the differential? to see what it really is?

 

Back in the day, there weren't a lot of the choices there are today. There was also the earlier Ford Equa-Lock, up until around '67, with the later Traction-Lock being stronger in general. The weakest link in the latter was the cover, which could crack and break where it was machined flat, inside of the ring gear bolts when subjected to a lot of hard 4-spd (or 4x4) use. Weren't a lot of options for stronger back then except the Detroit Locker- which could be a lot of fun when taking a rookie for a ride, you could make the car twitch pretty good with a little throttle manipulation. One thing to avoid, as I found out the hard way, is a 28-spline Locker, if you're gonna do any drag racing- pretty hard on the axles. I broke one at Fremont in '76 on the starting line- luckily the old slicks I was running weren't sticky enough to make it take a hard right turn

 

Eaton has a good rep.

 

My model A had a 9 in with a stock Trac-Lok differential. I got it off EBAY (the trac-lok) and rebuilt it with new clutches. A friend lent me the special tool to set the clutch pack clearance. It works fine although I do get a small shudder on some low speed, tight turns. It's pretty slight so I think it will go away when I get some miles on it. I'm very pleased.

 

I had it built by Currie. The receipt says it was a Torsen. The original agreement was a Tru-Trac. No, I did not dis***emble it to check which it was. I installed it and ran it. It is a torque splitting differential, one or the other. If I launch with one wheel on a painted crosswalk the same thing happens. Or if I get one wheel stuck in dirt. I plan on going to a Traction Lock.
That's the reason I am here on this thread.

 

Interesting.

I know my Detroit locker works like it should....and I ***embled the rear myself.

Sorry you're having problems with it. that's a bummer.

 

that's good. Mine does.

 

I was considering a locker. I need both wheels grabbing. It's the trade offs that bother me. I drive the car on the street. A Traction-Lok might be better.

 

I've put over 100k on locker equipped cars...I don't understand why folks think they're not streetable.

 

Locker, or limited slip?

I put over 250k on short-wheelbase 4x4 rigs that were not all that heavy, taking the locking automatic locking differential out after just 10k.

I had a Detroit Locker in the rear, and when I got on the gas it would try to change lanes in one direction, and when I got off it tried to change lanes in the other direction. It did the shuffle on every (manual) shift. It was too hectic to drive long distances. I would not even try that with a lightweight hot rod. I'd rather have a spool, or a clutch-style limited-slip.

I have had customers tell me that they are less ornery if you have an automatic, because the drivetrain is never fully unloaded like with a manual transmission.

 

I have two D/L in cars I own and their quite streetable. The only time it can get a little interesting is when it's wet out, accelerating around a corner. If your aware of what you have and how it reacts it's a non-issue.

 

Gotta agree, never had a real problem driving with a DL on the street- once you get used to them, their little habits are pretty predictable- and can be fun with an uninitiated p***enger. Do make a little noise occasionally lol...

 

The 9" diff splits apart. At least every one I've worked on has.
The Po' Boys approach to limited slip is to add shims under the side gears until all the clearance is taken up.....and then just a touch more!
But yeah, a long way from being ideal, and a Moly additive should be used in the oil to keep 'em from galling. I've set a few up like this "Back in the day."

 

Roughly the same sound as breaking cro-mo 35-spline axle! Always a joy for the few seconds when you wait to see which one it was!

 

Detroit Locker in an OT car with 18.5" wide tires for me. Tends to wear out the insides of the treads though. Never really felt that it compromised drivability any more than the 4" tires in front and 18.5" tires in the rear.

 

I drove my Super Cobrajet with 4:30's and Detroit locker on the track and street including in the snow and ice for 20 years with NO problems.

 

Now I know why some folks think they're unstreetable. Thanks for the insight.

also, how the axles are aligned might have something to do with the tendency to move around? if the car is not tracking perfectly straight, that could happen. Tire size/pressure might also affect it.

 

We have one car using a DL now for several years in a car built for autocross.....it performs as expected
thru braking, rollout and acceleration. Eaton offered a few different springs for your application.
Where the old Lockers were noisy, this one is non perceptible, at least over engine noise.

 

I've been looking at the helical 6 gear posi set up for my 31 tudor with a 9" myself.

I like the idea of it being mechanical vs. clutch packs.

It's a 440, 2200 stall 727 that I intend to drive aggressively and an occasional romps down the strip. The 440 should make some good torque and though hopefully I will keep car weight down I still want something that will stay together back there.

 

I would NOT recommend a “Detroit locker”. I have one (3:89 in a 9 inch) and while I use it for track duty;it definitely does NOT like the street. It pops,snapping noises happen,and it does not do well even in a slight turn.However,it does its job perfectly at the track which obviously is straight line acceleration. Flatheads Forever!!

 

I had a Detroit Locker in my 55 for almost two decades, it was a quiet one. I got another for my Chevy II, it's been in there since 2014, almost 30k miles. It's a noisy one, it was on ebay as being a used NASCAR unit (larger bearing size than the other, though both are 31 spline). The noise doesn't bother me at all, I mostly only hear it in parking lots and gas stations. I think it sounds cool in a bad*** 60s street car kind of way. The Boss 302 guys get it.

 

I have over 50k miles on a lok-rite ( before Richmond bought them out ) it " talks" a bit but the performance has been flawless for 22 years .

 

Sounds like most of the Detroit Locker devotees are from places that rarely get precipitation, especially the frozen white sort.

Under those conditions a clutch type limited slip is a lot more forgiving.

Of course a hard core hot rod rarely ventures out in anything but warm dry weather.

 

It's worn out, put new clutches and steels in it, shim for breakaway torque.

 

I don't drive in snow in the go fast cars, but plenty of rain....I've found that the type of tires you have is far more important than what type of limited slip you have. And driving carefully is required for anything that has some HP, of course.