Limited Slip Diff Upgrade
Are there companies that I can buy and instal a LSD (4.10 is fine) for my truck?
Thanks,
Chris
A guy in the Excursion forum installed one on his truck and wishes he would've done it sooner. He said that even with the snow on the ground, the truck felt so confident in 2wd the didn't really need to use 4wd.
As soon as I get some money, I plan on doing the exact same thing since my truck has an open diff too.
hi CP Louie and welcome to FTE 
There are a number of very good after market limited slip differentials. Tru-Trac, Detroit and Auburn make quality equipment.
If you are going to spend the money, don't get a stock LS. The gear style limited slip units (Like True-Trac) work a lot better. This cut is from
Ford 10.25 Differential Lockers Auto Parts: AIR LOCKER,ARB,SELECTABLE LOCKER,LOCKER,10 1/4,10.25,10 1/2,FORD 10 1/4,FORD 10 1/2,DIFFERENTIAL,FORD 10.25,DETROIT,DETROIT LOCKER,10.5,STERLING,LOCK RIGHT,LOCKRIGHT,POWERTRAX,LIMITED SLIP,POSI,POSITRACTION
True-Trac limited slip for '83 and newer Ford 10.25" and 10.5" with 35 spline axles. The True Trac limited slip uses a worm-gear design to bias torque from one tire to the other, providing extremely smooth operation. Since there are no clutches in this unit, there are no parts to wear out and no need to run limited slip additive in your oil.
) at Eaton who informed me that they plan to make the eLocker for the Sterling 10.25/10.50 rear axle. All he could say was that it would not be available in 2010... maybe 2011.
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A clutch based limited slip is more "grabby" than a worm gear based limited slip. The gear based also does not need "friction modifier" added to the lubricant whereas the clutch based limited slip needs to have the correct amount of friction modifier added to work properly.
If you don't drive in snow, any of the limited slips will work well for you. If you drive in snow, I would suggest the True Trac limited slip; however, realize all traction aids when "locked" (even the True Trac) will change the handling characteristics of the truck somewhat (just less with the gear based True Trac).
Randys Ring and Pinion is a pretty good place to purchase your differential stuff; although, if you look up 4x4/driveline/differential in the yellow pages you will probably find a place that will order and install whatever you want. I know it'll double the price, but if you're having differential work done, think about putting one in the front as well (if you have a 4x4).
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I'd look real hard at the Eaton (Detroit) TruTrac limited slip differential if I was wanting a limited slip.
I've run an Auburn, and it was the cat's meow, but those things eventually wear out, just like an OEM limited slip. The auburn was real aggressive off road: punch the gas and watch two rooster tails of dirt, mud, sand, or snow spray from the rear view mirror. But after, say, 50,000 miles it wasn't quite as good. Then by the time it was 75,000 miles is was not very good at all. Finally by 100,000 miles it was completely back to open differential. It's a single use product. Non-rebuildable. when it's done, it's done.
The TruTrac uses worm or helical gears to bias torque instead of clutches. The good news is that it doesn't wear out or performance doesn't degrade over time. The bad news is that (I think) there isn't any preload on the unit. That means in extremely low traction situations such as a tire on ice or a tire off the ground, the unit may not be as effective as a clutch driven unit where the preloaded clutches can still provide some torque biasing ability to the other wheel with traction. But that's the disadvantage of any limited slip... at some point they will still spin one tire.
If you're going to get a limited slip, I think the TruTrac is the best choice.
Sometimes I have to drive on grass, and we did get stuck in a few inches of snow when my son backed one wheel off the road.
These have all been really good comments, and i appreciate everyone's help. I will have to sort through this. I have air on board, I just put in a compressor. I had no idea that someone made an air operated LSD. I have air bags and I put in a little regulator for that as well. Chris
For your education, the ARB is not a limited slip, it is a true selectable locker.
When it is engaged, the axle shafts are completely locked together like with a spool - no differential action whatsoever.
They are fantastic if you learn how to use (when to lock or unlock). But they are $$$. You get what you pay for!
Personally, I am very excited to hear about the Eaton eLocker and will be watching for them! They work the same as the ARB (true open or true locked), but use electricity rather than air for a much lower installed cost.











