Another score from the candy store.

Decided to hit the candy store (Summit) because it's been about a week.
Haven't gone my normal frequency cause the demo shelves have been a tad sparse.
Strolled down first isle but what before my wandering eyes appeared a posi diff. All this summer box after box of open diffs. Rarely a posi and that was usually a Ford, maybe Mopar.
But today I had to put on 2 pair of readers just to make sure. I even took it to the tech counter and had them double check. Sure enuf it's a fit.
Time to read up on swaping out diffs.

Update:
I was gonna wait until spring to tackle the diff, but a warm streak was predicted for Fri, Sat and Sunday and I had the itch to get it done. After hitting the manuals and having watched a few swaps on the TV gearhead channels, I pulled the trigger.
Got everything dismantled in a few hours. With the ring gear swapped and new bearings pressed on, the shim fitting began. I have to admit after tearing it apart, I was a tad pooped and it was past dark and getting chilly. So shimming would commence Saturday.
I knew fitting shims was going to be tedous and since the axle was still in place, getting situated to do the job under the truck was a priority. Earlier this summer, I had picked up a set of nice jack stands and this is the first I've used them and the height was perfect for the task at hand.
I hate to admit it, but shimming took way longer than expected and 2 things contributed to that; inexperience and gravity. The weight of the diff kept pushing the outer bearing race out of position. That was really the biggest pain.
Finally got things really close and figured it was close enough to paint and see where the gears were hitting. A .005 change was all that was needed. Then backlash was checked and came in at .003. The entire drive line rolled over very nicely after torquing the caps down the final time.
Even with a family get together, I still managed to get it all buttoned up and ready for a drive tomorrow.
Knowing what I know now, I would serously consider removing the axle to fit the shims. That way gravity works for ya and not against ya. And for us older ol'farts that can get exhausting really quickly.
Hopefully, I did everything correctly and all goes well.

I just remembered a question I had...
Can the factory stock open diff have pieces added to it, in order to convert it to a limited slip diff?
In other words: pop out the original open diff, swap / add parts to it and convert it to a limited slip /posi diff?
..and I don't mean welding gears together....lol

Thanks in advance for your replies.

.003 backlash? That is way too tight for a street driven setup. For a 12 bolt .006-.010 backlash. If they are used gears I like to check the backlash before disassembly and make note of it, and match it upon reinstallation as the gears had worn and created their mesh at that position.

For the shims, these "Super shim" kits work well, sandwiches the thin shims between the thick shims and makes a shim sandwich. I have not used one, but a housing spreader is a good thing to have to assist in getting the shims in and out and establishing carrier bearing preload. On the setups I have done, I have just got it shimmed tight (no movement of the carrier side to side), then pack a few thousandths extra shim in and carefully tap the shims and carrier in.


On an open carrier, a lunchbox locker is one way to get a two tire fryer with the open carrier.

The reason for the upgrade was not to do peel-outs.
We plan on finding a decent 20' to 24' trailer camper and this is the puller. I do not have a heavy foot.
Since I did not use any tool to tap the shims in I figured that by the time everything settles in, there will be an additional .003 in backlash.
I didn't have much choice, the Yukon bearing & shim kit had .005 as the thinnest shims. That .005 shift gave way too much backlash.
I figured to run it a bit and then recheck the backlash. It only costs $7 for the gasket and a couple hours.
I also have a couple of ways to monitor the temp, so I'll keep an eye on it.

That’s kind of the rub of the situation, the carrier bearings (and pinion bearings) both want to be preloaded, running with improper (not enough) preload will very likely lead to an early failure for the bearings.

What you set as the backlash should remain consistent, if you set it up at three and five hundred miles later it’s opened up to six, something is moving or wearing or both. Not good or desirable. Now over 1,2,3 hundred thousand miles, depending on usage, yes things will have likely opened up some from when new, but still not much considering.

With used gears, they have established a mesh pattern with the original installation and all the miles they have accrued, going and making big changes to pinion depth or backlash, or both is effectively changing that mesh pattern and can lead to noises or wear. One of the reasons why a lot of people won’t mess with installing used gears that they did not take out of a housing themselves, very easy to become a nightmare trying to get the pattern to come in.

.005 might be the thinnest shim (too thin and they can spit out under load), but you should have an assortment that has a good mix in thousandth increments from 5 to 10, maybe some half sizes in there.

It will take some figuring, but you should be able to play with what you have to arrive at the correct backlash. Swap a 5 or a 6, or replace a 15 with a 7 and 9 or 8 and 6 etc to achieve those increments needed.

If you feel confident at .003, I wish you the best of luck, if I were you however, I’d open it up to .007-.008 and verify there is enough carrier preload. Best would have been to measure and record backlash with the open carrier and that would be your goal to achieve.

14 Bolt Full Float swap. No shims needed. Just sayin.

SquareRoot said:

14 Bolt Full Float swap. No shims needed. Just sayin.

Click to expand...

No carrier shims, still pinion shims.

Why stop at the 14 bolt. 2.5 ton Rockwells is really the best answer.

SquareRoot said:

14 Bolt Full Float swap. No shims needed. Just sayin.

Click to expand...

This was a 12 bolt semi float.