Truck details in signature. It's a 2WD. Got it stuck in the yard today. The yard! The drivers rear tire drop into a mud hole and the passenger rear tire was on dry, hard packed ground. Drivers tire spun in the mud while the passenger side tire sat there looking stupid. Truck has 150k miles on it. Thinking the LSD is worn out. Is there a better option for this axle? Does anyone make a lunchbox locker I can put in it? Being a LSD, would I need an open diff carrier to install a lunchbox? Thanks all.

 

Use the tow hook I showed you in the other post as it is a lot cheaper.

 

The factory diff was never very tight to begin with, the good news is it's dumb easy to make it a lot tighter.. just restack the clutches with an extra friction disc on each side.

Yes the Detroit(Powertrax) Lockright and yes that goes inside a an open carrier only.

 

Are you saying to pull the truck out when I get it stuck rather than rework the LSD? This time it was easy, I was in my own yard. I've had a time or two at the dump where it was a bit touch and go (this area gets swampy spring into early summer). Last thing I want to do is ask one of the bull dozers at the dump to pull me out.

I know you can do that with the 8.8, have one in my Jeep. But I haven't touched one of these larger axles. Not even sure what axle is in this thing. Do you know of any good write ups on the axle and tightening up the LSD? I regeared the Dana 30 and 8.8 in my Jeep myself, it's work I'm able to do. I think I will try more friction discs before I go to the hassle of swapping out the carrier, unless someone has a better option?

 

When these limited slip rear ends were brand new they wouldn't do what you wanted in the situation you described. You still would have been stuck.

Google limited slip and bias. Still probably won't really help. It's one of those things you have to experience to get a feel for. Very judicious pedal work with the brake and gas might have got you out. With a manual trans it probably wouldn't have helped at all. It's a tool, you use it to do the work. It's rarely going to do the work for you.

Same goes with a locker. Weight distribution makes a locker a bad idea in a pickup for most people. Until one puts you in a ditch you won't believe it can be bad for you.

The limited slip in my truck has helped me out a handful of times in over 15 years. It does double duty as a farm truck and spends its share of time off road. What it does best is to get a jump on the Mustangs and Camaros at a red light.

 

The rear axle is a Sterling 10.25. I have tightened up a few 8.8" LS rear axles, never a Sterling. Concept is the same , but no hands-on experience.

 

If you have worked on an 8.8 before then you can work on a Ford 10.25/10.5 they are setup the same way only the 10.25 is larger, heavier and doesn't use c-clips. If it was me I would get a better limited slip or a locker in the rear instead of rebuilding what you have. The Detroit Truetrac, Detroit Locker, and Yukon Grizzly locker are all good units.

 

A lot of people seem to like clutch-type limited slips. I'm not one of them. I'm not saying others are wrong, but in my opinion they offer the worst of both worlds. If they are tight enough to help when you need them then they are too tight and give handling problems on snow. And if they are loose enough to be acceptable on snowy roads, then they are completely useless when you need them. (The worn out limited slip in my 205,000 mile F-250 will easily spin one tire on gravel, but still will cause both tires to scrub, leading to oversteer when coasting around a corner on ice.) Again, others like limited slips, and maybe you're one of them. If so, then go ahead and rebuild your limited slip, it's probably your cheapest route.

If it were me, I'd take the opportunity to switch to something better (in my opinion). I've driven automatic lockers in a CJ5, an F-150 and an early Bronco. Personally I think auto lockers are very acceptable on the street (I greatly prefer them to even a fairly loose limited slip). They can get you in trouble if your right foot is too heavy at the wrong time, but they aren't hard to get used to if you are willing to adapt to them. Still, I wouldn't go to the effort of putting in an open carrier to be able to use a lunchbox locker. I'd go to a full-carrier auto locker like a Detroit or Grizzly.

If I didn't need the positive nature of a locker, I'd go with a TrueTrac (and that's what's on my list for my F-250). They are more streetable than an auto locker, and in a rear axle especially can still be pretty positive (a couple of clicks of emergency brake effectively tighten them up pretty well).

And of course a selectable locker would give open diff streetability with the positive action of a locker. They tend to be more expensive, with a more complicated install (since you also have to deal with actuation). But they can be good options for some as well.

 

The truck is a seldom used tool, used for truck things. My DD is a Civic (don't love the car but love the fuel economy). When it snows (two, MAYBE three days a year, MAYBE) I drive the jeep. I'll look into the full carrier auto lockers. WAY too cheap for a selectable locker.

 

Since it was your yard, it's still handy as a "testing ground" for you. When it's wet and snotty again, put one tire in the mud again and see if it slips. If it does, do as was suggested by Hard Scrabble and, with a light throttle foot, start pressing slowly on the brake pedal too.
The point is to slow down the slipping wheel, to reduce the speed differential until the clutches can grab. Or at least grab better.
Better yet, maybe don't do it until the unit is rebuilt or replaced! Might not work as tested, and you don't need to get stuck yet again in the yard.

But as was also alluded to, your mileage may have already killed any chance your old unit has of working until the clutches are replaced.
In my experience with the older Ford 9" and Dana axles, we used to consider a factory limited-slip as potentially needing a clutch refurb in as little as 60k miles. That was generally when we noticed ours, and customer's trucks start to lose much of their LS'ing abilities.
I'm guessing that at 150k miles, even your Ford 10.25 is very likely beyond it's normal life expectancy. But also as said, new clutches are typically inexpensive and easy to install.

Oh, and all limited-slip diffs, including the non-clutch types such as the Truetrac, are often helped along by applying the brakes. It's just something that was "known" and assumed as general practice when needed back when trucks were someone's sole source of transportation, survival and livelihood. I've seen it written about in books and magazines since the sixties. In more recent years though? Not so much anymore.
I can't remember the last time I read about it in fact, except in some possibly obscure mention on a forum.

Good luck.

Paul

 

One of the things you are doing is brake torqueing, torque splitting or brake biasing. You are putting close to the same torque to the traction wheel as the spinning wheel. You use more torque to overcome the brake so more torque to the traction wheel. Differentials are strange animals. Traction is like magic right up to the split second it's gone.

 

With clutch-type limited slips there might be some benefit to applying some e.brake. If the side that's slipping happens to get more braking it'll definitely help (not so much if it's the other way). And getting the clutches to stop slipping might help them grab as Paul says. On paper it seems like it can't help much, but it's been accepted folk-lore for so long that it must help, at least a little sometimes. And with a little brake on it can be easier to roll into the throttle slower so you don't break the tires loose as easily. So go ahead and try it (it certainly can't hurt if you're already stuck).

But with the TrueTrac it's a sure thing it'll help, and help a lot. TrueTracs deliver 3.5x as much torque to the tire with traction as they do to the tire without traction (or 2.5x for a lighter biased diff intended for a front axle). So if you add say 50 lb-ft of drag to the spinning tire, the TrueTrac will send 3.5x50 = 175 lb-ft more torque to the tire with traction. Even if you subtract the extra 50 lb-ft of braking going to that tire, you still have 125 lb-ft more torque at the tire with traction. (And obviously, this is for using the e.brake. Applying the foot brake puts more drag on all four tires, and isn't likely to be a net positive unless you have 2 TrueTracs that you are trying to get to lock up).

 

Cheapest option

 

If it's used mostly for a farm truck and not on the street much then I agree.

 

I was being sarcastic, it's a bear to drive a welded diff around. I did it for 3 years in an old truck of mine, probably put 20,000 miles on it like that.

Would I do it again on a semifloat rear end, no. But a full floater I wouldn't worry about. But, that's me, and I don't always recommend people to do what I do, lol.