Differential Question/Issue

So, I got stuck in the snow yesterday (Yes, I am one of those who uses my vert as a daily driver all year round).

According to the Marti I have the 9" Traction-Lok differential, yet when it happened the right wheel kept spinning in the ice and power never transferred to the left wheel.

Other than opening the rear carrier and looking, is there a way of determining if I do , in fact, have Traction-Lok, and, (assuming I do) troubleshooting why it wasn't working in the snow? I know I have the 9" rear, if the differential isn't a posi, what is involved in "upgrading a 9" differential to a traction-lok differential?

Sorry if this question is very basic, Thanks for all the help I have gotten, this board is invaluable.

Haven't been in rear axles for a long while, but I think I recall the way to tell is to lift rear of the car. Turn a wheel by hand. If the other wheel goes same direction it's a traction lock. 

also while driving, if you have one, when you take a sharp turn at low speed, you'd hear sometimes or even feel a 'clunk'

To add the t-lock you need to replace the ring gear carrier in the differential. Quick performance sells a kit with a new gearset, t-lock and all the bearings for about $500.00. I have that in mine although I don't get mine out in the snow. 

I thought you were in Florida for some reason... 

I dont know how the Ford traction lock works, but a lot of these nees some resistance in the spinning wheel to work. I can see a situation in snow/ice where the wheel will spin with so little resistance that it wont be enough to activate the lock mechanism.

The Ford Traction Lok diff is a clutch type limited slip. There's a specification in the shop manual regarding break-away torque, IIRC it's around 40 ft/lb. You can test the diff by placing the car in gear, block one rear tire, and jack the opposite just off the ground. Use a torque wrench set to 40 ft/lb on a lug nut and try to spin the tire with it. It's not exactly how the factory shows, but it'll get you close. If it rotates at below the 40 ft/lb setting, then the diff needs to be rebuilt, or it was swapped for an open unit at some point. In my experience, failing clutches in Traction Lok units bind, chatter and make all sorts of odd noises and clunks while turning. 

The Ford TractionLok uses friction and steel disks and springs. They all wear out, especially after nearly 50 years.

Tony is correct, if one wheel is on ice and the other on solid ground it's likely the one on ice will spin, never transferring torque to the other side, even on a new unit. It's easy to overload the spring pressure. One trick is to apply the emergency brake enough to create enough load on the spinning wheel so some torque is transferred to the other wheel. Easier said than done with a manual transmission.

Even the Eaton TrueTrac may not completely lock up in that condition, but light braking will work with them.

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The only one that locks up is the infamous Detroit Locker, but can cause control issues, especially when cornering and it locks up. One of two things can happen when it locks and the car is accelerating on slick surfaces, the back end spins around or the front tires won't turn the vehicle and it plows straight ahead, backing off on the accelerator solves both problems.

Hemikiller said:

The Ford Traction Lok diff is a clutch type limited slip. There's a specification in the shop manual regarding break-away torque, IIRC it's around 40 ft/lb. You can test the diff by placing the car in gear, block one rear tire, and jack the opposite just off the ground. Use a torque wrench set to 40 ft/lb on a lug nut and try to spin the tire with it. It's not exactly how the factory shows, but it'll get you close. If it rotates at below the 40 ft/lb setting, then the diff needs to be rebuilt, or it was swapped for an open unit at some point. In my experience, failing clutches in Traction Lok units bind, chatter and make all sorts of odd noises and clunks while turning. 

Click to expand...

And don't forget the additive.  We did and the diff made all sorts of clunking noise in a turn.

Something about lubricating the clutch plates.

mike