You either tightened the nut to far or not enough. To read the total preload you have to disconnect the driveshaft and pull the axle shafts from the carrier. you will also need a dial or deflecting beam style torque wrench to measure the pre-load properly. You are just supposed to tighten the nut until you obtain the proper pre-load.
If you tightened it to much you will have to pull the whole rearend apart to replace the crush sleeve.

 

Thanks Dan, if I tightened it to much will there be more drag on the in. lb. wrench. You stated 25 to 45 in lb's total preload correct? If it takes quite abit more than that, that means I went to tight on torque correct? Then carrier has to come out,pinion out and then reinstall with new crush sleeve right? Boy can I kick myself in the a.. .This won't take place till morning. I sure thank you for the HELP and reply's. Rick

 

When you change a pinion seal you have to pull the axle shafts in order to measure and record the rotational torque of the pinion using an inch/pound torque wrench.

Once you have pulled the pinion flange, and replaced the seal, you tighten the pinion nut in small increments until the rotational torque on the pinion is 3-5 pounds greater than your earlier recorded measurement.

 

dodge3500, problem being I didn't do a earlier measurement(ya, go ahead and say it I agree)but am on it now and in lb reading is about 12 to 15.(couldn't wait) any thoughts what my final torque reading should be???

 

Well guy's,I've exausted my half in drive snap on impact and needs to go tighter, breaker bar and pipe????still spins like butter(scary). 25 to 45 in lbs. eh?

 

Dan , dodge3500 thank you guy's for help and replys I'm all set.Runs down the road quiet as mouse now(not diesel noise, just the rear end is quiet now and smooth) live and learn I guess.. thanks again for the help Rick......

 

I just want to try to help you out. I know how if feels if you feel like you are in over your head on something.

Well lets try to work through this. If you say it spins like butter and it is howling, it probably means that you never reached the proper preload meaning that the pinion nut is too loose.

Since the the total torque to rotate(TTTR) is 30-50 inch/pounds for new bearings and 25-45 inch/pounds for used bearings, I would tighten the pinion nut until I hit a reading of 35-40 inch pounds. That measurement would put you in the middle of both new/used bearings. I would drive it and see if that has eliminated the howling noise. If not, I would only tighten the pinion nut until I achieved another 5 inch/pounds for a total of 40-45 inch/pounds.

If that still does not eliminate the howl, at that point I would get a new crush collar and start over. Just remember to have the axles and driveshaft removed when checking the preload.

Realize that this is the best you can do without knowing what the preload was to start, and the correct way to do it is always with a new crush collar.

 

Well i got the LS unit swapped in this past Saturday.

Every thing went as planned. It took a bit of trial and error getting used to the side adjusters after working on so many Ford rearends, but I finally got the hang of it. I kept forgetting to rotate the other side in the opposite direction.

My stock unit had a BL of .005, and that is where I set it with the swapped in LS unit.

The 12 ring gear bolts proved to be a bit much for my impact to handle, so I ended up taking them down to a shop with a better impact.

The only other real issue was cranking the bearing caps bolts down to 207 ftlbs. I couldn't get enough leverage underneath the truck and resorted to pulling on the wrench from the wheel well while a friend pushed from the other side.

I am already very pleased with the stock LS unit performance.