Hey all, I've got a 95' extended cab, short bed 4x4 with an automatic and a 5.8L I've got factory open differentials on both ends and was looking to start upgrading to Limited slip.

My question is, will a limited slip unit for any ford 8.8 with 31 spline axles work? Or do I need something specifically for an f-series?

And as far as the front end is concerned. My truck has the Dana 44, is there any other vehicles that would share a traction lock unit with that? I'm shopping around for used or rebuilt units so most of my browsing is trying to look up other vehicles that will share parts.

Thanks in advance.

 

All 31-spline 8.8" diffs are interchangeable. D44 diffs have 1 case break for gear ratios; you need the common low-number case.

But changing diff carriers is expensive & complicated. It's much cheaper & easier to buy a good used axle with the diff you want, and swap it under your truck, even if the clutches are worn out & you have to rebuild the diff. You shouldn't have much trouble finding a D44IFS (TTB) chunk or axle with factory LSD since so many people swap to a solid front axle. When I swap my rear axle again, it'll be for an '04-up E150 8.8" with factory disk brakes. That swap will require some fabrication to move the spring & shock perches on the axle, and to make the e-brakes work. But you can look for '87-96 F150/Bronco rear axles. Click my black Bronco in my signature & read the captions in the 8.8" Axle album.

 

Do you know what the break point is on the lower number case? I've still got to check the gears that are in my truck to find whats in it now.

How come changing the differential would be so difficult compared to buying a used axle and rebuilding the LSD thats in it?

 

Have you ever set up a differential?
It's not particularly difficult but it requires some special tools, a fair amount of time and expertise and... there is absolutely no room for error. "Close enough" is not acceptable.

 

I haven't personally, but I our senior mechanic at work has set up quite a few for his trail rigs, and one for his mud bogger he used to run. I would imagine I could get him to lend me a hand to teach me the ways.

Wouldn't I need to set up the differential if it was removed to be rebuilt as well? Like if I bought a used LS axle from a salvage yard and rebuilt the LSD.

 

If you do have some one to set it up, you can pick up a used Factory trac loc pretty cheap. ECGS has one for 75, and 100 to rebuild it. From what I hear these guys are pretty good. I have been talking to them on the phone and they will be regearing my truck in teh next few weeks.

http://eastcoastgearsupply.com/c-121...sed-parts.html

 

Thanks for the link. I suppose that pretty well answers most of my questions about the rear. My only other question are what are the opinions on lockers vs. LSD vs. The Lincoln Locker.

I'm going to imagine the Lincoln Locker is the least favored due to not being able to overrun the gears in corners. But what about Lockers Vs. LSD? any reason why to go with 1 over the other? The truck isn't a daily, it's mainly a poor weather vehicle and mud toy in the making.

 

This site shows case breaks:
http://www.drivetrain.com/parts_cata...nd_pinion.html
This caption explains how to tell what the truck's factory gears were:

If you rebuild a diff that's set up, you simply put the shims back where they were, and it stays set up - no trouble.
http://www.fordracingparts.com/downl...And-Pinion.pdf
A Lincoln-Locker effectively has no differential gears (and mine actually has no diff gears); it drives like a spool. Read this:
http://www.fordf150.net/forums/viewt...=507588#507588
If you drive on pavement in any kind of bad weather, you DON'T want a spool in back, and you can only get away with it in the front if you leave one hub UNlocked (which makes steering unpredictable). WHERE are you (put it in your profile)? What kind of "poor weather" are you talking about? Rain, snow, ice?

 

Thanks for the links. I figured the Lincoln-Locker was probably the worst of the options for all around use. Just figured given it's free, if it was a decent alternative I'd try that route.
I live in north western Ohio, so all of the above. Mainly rain and snow when it's on the road though.

 

Rear lockers can be very difficult to drive in the snow. There's not enough traction to get them to unlock in a corner and they get very twitchy as a result; a loose LS like the Ford Trac-Lok is much more forgiving but can still bite you on occasion. Torque-proportioning diffs like the Dertoit True Track are better yet but you won't find a used one in a boneyard.

In the front, a locker can be extremely dangerous in the snow because if there isn't enough traction to unlock the diff, the truck tends not to turn. If you put a locker or LS in the front, you need to keep the hubs unlocked except for when you really need the extra traction

However, when you have to unstick yourself from deep snow, there is nothing better than lockers front and rear

 

That does make perfect sense, I don't drive with the hubs locked unless I need them. Actually that's why I got rid of the automatic hubs one didn't want to unlock properly. I can't say i've driven a vehicle with a locker in the snow but I have driven some things with a very twitchy rear end so i'm not terribly concerned with it. But definitely something to keep in mind.

Are the powertrax lockers any good? The ones that install in place of the spider gears? I know some places people seem to say they're great and others that they're garbage. Just want to get a really informed opinion.

 

Read that thread I linked (the last link in my first post).

 

I finally got the axle code off the truck which is H9 so according to that chart is an LSD 3.55 and it will lay 2 black lines down if you power brake it ( had to test it) but if you spin one of the rear tires when in the air the other one either doesn't spin or spins the opposite way, which from what i've seen on positrac-gm's they should spin the same way. Is that right? Or are fords different?

 

The clutches are very worn; time to re-build.

 

Thats what I was figuring. Just seems weird it'll spin both tires on pavement but yet not function all at the same time. lol. But I already talked to my guy at work and he said he'd walk me through rebuilding it so I'll probably take care of it in the near future.

Thanks for all the help guys