I currently have an open rear and get tired of getting stuck because 1 tire spins. I found a take out limited slip unit on ebay for just under 150 shipped to me door.

Could I just swap it in or do would I need to check all the lash and spacings and such

 

Is it all taken apart or is it all still assembled?

 

when i did mine, i did gears and all. i just swapped it all, left thr ring gear and bearings on the LS carrier. i have over 1500 mi on it and no issues. i have to pull and reseal the cover this week, so i will be able to look in there just to be sure

 

I think its together

 

sorry for small pict heres link

10.25 10.50 Ford Sterling Posi Trac Lok Locker F Series: eBay Motors (item 200537035671 end time Nov-05-10 17:00:00 PDT)

 

it looks complete

 

Would it be worth doing anythign else while i'm in there? And how do you actually swap? I assume you pull each side of rear axle and just switch out

 

theres not much else to do in there unless your pinion bearing are bad, but you would know that by now. if you are not pulling the pinion, everything should be spaced correctly

 

I keep looking at this carrier, and it doesnt look to be a LS or an Open, but a true posi, interesting! I am going to research this more!

As for what you can do, no you dont have to set any spacing on it. Its the complete carrier. All you need to do is take the gears off of your carrier and place them on the new carrier. I believe 5/8th bolts are all thats holding that ring gear on.

You wont need to remove the Pinion gear as long as you are using the same ring gear. No adjustments needed.

To make this happen, you will need to unbolt the axle halved at the hub, pull the axle halves out by about 3", open the differential cover, the gear oil will spill out (icky), unbolt the '4' carrier bolts holding the carrier cap on. Gently pursuade the carrier out. Install is reverse.

 

I personally wouldn't buy it. I've never had one of these, but I heard the clutches in this design doesn't last long. 6 months to a year. So if this one is just, it may be worn out. Get one out of a Superduty. Those are much better.

FORD F250 10.25" DETROIT TRUETRAC 10.5" POSI 915A550 : eBay Motors (item 330450659383 end time Nov-08-10 17:09:19 PST)

 

Actually, I hate to burst your guy's bubble, but if he's replacing the carrier, he has to check his shim spacing on the Pinion, due to them being different carriers.

Now, will he most likely have to change the shim? No, probably not, but it needs to be checked.

New bearings and new Clutch packs on the stock unit and you should be good.
If its a 3 spider unit, then even better.

Once the bearings are pressed on and your soaked clutches are installed and your ring is on, you have to install the carrier and check for pinion shimming using the gear paint.

There are how-to's everywhere for that.

Then once you are done there, you'll have to set the backlash, diff carrier = diff shim setup.

Remember, when you remove your carrier, keep the shims separate per side.
you'll use the same total thickness for the shims.
I'd pick up a new set of shims if I were you and just replace them anyways.
But, try the carrier with the original shims in the original space.
You'll have to bolt it in yet again and torque it down, then check your backlash.
You'll probably have to find somebody with a gauge you can borrow for this, I had to borrow one.
I do not know the correct backlash spacing for our axles. I'm sure MadVan Bill does and Cody as well.

 

you are right. Those carrier bearings need to come off and be replaced and the shim packs adjusted on them. I would start by taking off the bearings on the one in it and using those shims without the right tools to measure it. That should get it pretty close if not right on. Those bearings don't look good though so you need to replace them.

And I never heard anything bad about those clutches. I've never worn one out either and I've put a couple million miles on them with my trucks. My f350 came with a locker in the back and I swapped rear axles with my son for his 400,000 mile limited slip. I still can't turn a wheel on it when I jack it up. Not even with a 6 foot breaker bar. The clutches looked perfect in it when I rebuilt it so I put them back in.

 

Yeah, the clutches in our axles are not bad. The only problem we have with our axles is spider gears when you put on monster tires.

I've had my truck a year, and the rear end clutches are so tight, I have to coast the truck to turn tight. It pushes the front end across the pavement.

Thats pretty good Ryan.
I somehow managed to break mine loose when I was messing with something. I don't even remember what it was, but it broke loose like a metal bar snapping, I about went head first into the ground. I had about everything I had on the breaker bar. I musta been taking the tire off, didn't even worry cause the clutches were so tight. haha.

 

If you are only replacing the carrier, you don't have to do anything to the pinion.
Check & record the reading of your ring gear backlash. You will want to have the EXACT SAME backlash with your "new" carrier installed as your old one. If it is not the same, it will make noise.
Remove old carrier. Note location of bearing caps & shims. DO NOT swap bearing caps from side to side on rear end housing. Swap over ring gear from "old" to "new" & install new carrier bearings.
Install "new" unit with original shims.
Torque bearing caps & check backlash. Set backlash EXACTLY as it was with old carrier. If backlash is not in spec., you can adjust it by adding shim thickness to one side of the carrier & subtracting the same amount from the other side.
When backlash is set, replace cover & fill with fluid & 2 bottles of friction modifier.
I have done hundreds of these when I worked for Ford. If the rear end is noisy, the noise of the diesel engine will cover most of it up.

 

Sterling axles are one of the easiest to swap carriers as long as they are Sterling carriers, after market ones require much more work. Ford made all their carriers virtually identical in width. The axle housings are not...so the shims stay with the housing.

All you do is install the carrier shims back where you found them in your axle...... bolt the ring gear to the carrier....it's that easy. Warm the ring gear so it drops onto (and off) the carrier. Get a couple bolts started before the gear cools off and shrinks into place.

More info:
Sterling 10.25 Trac lock rebuild