14; The pinion bearings are supposed to run snug and when you just put the nut back where it was the pinion will be as loose as it was before and the nut will be loose also and could of back off. At least use a new nut if you use this inferior method.:-RTFM I didn't say anything about rolling torque but having a light drag on the pinion is 10 times better than the "counting the threads" method. I guess the guy that fixed hundred of rear ends never learned anything.:confused:

The shop manuals are full of facts, figures, and specs but the seasoned mechanic doesn't have his nose in the book half the day. I have seen many of used rear ends with no drag on the pinion that worked perfectly and some that worked perfectly with so much drag on the pinion still after thousands of miles that you could barely turn the pinion by hand. When I set up my first few pinions I checked the torque and never checked one with a wrench after that and never had a problem. :rolleyes: 14; don't listen to me? No, listen to the guy that never was a mechanic. It's uninformed people like you that spread bad info in here.

Listen...you started this with your ******* comment above. So yoiu say you're a mechanic, but again I submit that you offered no insight to how it should have been done by YOUR textbook or memory of having performed 100's of rearend jobs...you think you could at least offered the guy some assitance ...instead you down-play or degrade those on this forum who do at least offer advise and assistance...(and no i don't mean ..."Yeah going to the dealer is like going to the dentist"...get over yourself...please. Its guys like you who taint this forum with your constant bashing and no real answers...and by the way...I'm am currently attending college as an Automotive technician....so who knows maybe some day I could officialy call myself a mechanic...but I wouldn't brag on it unless I could feel I was truly helping someone. And the call sign is Moyockpowerstroke...not 14....whatever...:-missingt

Moyockpowerstroke step back a little.

Just because you think EXv10 didn't detail the way he does it, he DID bring up an important point. While I agree both methods CAN work, the best way to do it is to set the bearing to the proper preload. Setting it back to the same spot only ensures you are probably not worse off than you were to begin with. I believe these differences were discussed in another thread.

Many of us that have done this for a long time can do it by hand, or compare the before to the after. There are specs for bearing preload, but if you are not going to be removing the tires, brakes, axles, (on a full floating rear you only have to slide the axle shafts out) and differential carrier, they are worthless because they only account for the pinion bearings.

The important thing is to consider all input while learning to do something, and since this is your first seal replacement, you are in no position to make a determination on what way has worked best for you, least of all which method is best.

Good post, Chris.

Let cooler heads prevail at FTE.

Thanks.

Pop

Good example here of why I said in the other thread that I wouldn't attempt this in the driveway. Avoiding this discussion, and the second thoughts that it is sure to inspire, would be well worth the $165 to have it done by an expert.

Actually, I think both methods are flawed, without CHECKING THE PINION PRELOAD IN THE FIRST PLACE.

Pinion seals usually do not just start leaking on their own. There is usually a cause besides wear unless you have a huge amount of miles or the pinion seal surface rusted. Loose pinion bearings, or a clogged breather. I would definitely check the breather before it starts to leak again ;)

But seriously, without removing the differential from the case and checking the real pinion preload BEFORE pulling it apart, you're playing with fire.

Yes, most mechanics do "count the threads", but they usually don't get a report back in 30K miles when it starts leaking again because it's loose, or the pinion bearings overheat because it went back together too tight.

If I ever have to deal with this on my Superduty (after having dealt with it on plenty of other rear ends, and having rebuilt quite a few too), I'm getting a new crush collar, a new nut, and doing it by the book.

Actually, if I ever have to deal with it, I'm going to use it as an excuse to upgrade from 3.73s to 4.30s :-X14

This is also just good CYA procedure too. You do a pinion seal, and a few months down the road it's making noise, you were the last one to work on it. You could have set it back to accepted "used" bearing preload, or where it was before, but if there is an impending failure in the pinion bearings you wouldn't have known.

However, in practice this is rare IMO. Usually if something is going wrong, you will notice real looseness, noise or roughness beforehand and two, most people won't pay for that kind of tear down for a seal. I (want to) agree that any rotating seal shouldn't fail unless there is something else wrong, but it does happen. Could be dirt, water, manufacturing variance etc.

I think this is one of those cases where yes you are playing with fire, but you won't get burned, it will just explode. And the chance of exploding rarely happens. Kinda like airplanes are the safest form of travel, but when something goes wrong, it really goes wrong.

All great points...I admit I was a little hot headed...EXv10...I apologize...lets bury the hatchet...we all need each other from one time or another and I hope we get along and make ammends. Thanks for everyone's comment and continued help and assistance.

Actually, just making sure you have a slight drag on the pinion when everything is buttoned up is a very good way to go. I have done it many, many times and it works very well. It sure beats taking it all apart right down to the lightly lubricated pinion and the torque wrench. Using a new nut when you do this procedure is a good idea also.

BTW what is the torque on the 12mm driveshaft yolk bolts? The source I have shows 86 ft lbs, is that right? Also is there a torque the pinion nut SHOULD be at? I read a running torque of 8-14 in lbs and a breakaway torque of 20. Do these numbers sound right. I am just replacing the pinion seal.

I did torque the 12mm12pt shaft bolts @ 86lbft...the Pinion Nut (of much debate) was returned to where it started plus 1/16th". I understand that where it started may have been wrong in the first place, but that was my reference point and since the companion yoke wasn't coming off without effort, I assume the bolt was not backing off on its own. I will keep a close eye on where I landed it. Use blue locktite or thread locker.

Thanks, I'm going to be working on it tomorrow! I've got the new Aluminum diff cover going on too :-D. MAN the 75W140 is SPENDY!!:-X09
I got Mobil 1 75W140 LS I'm going to put it in and see IF I need the friction additive on top of that. I picked up 8 oz of it but it looks like the Mobil 1 has some in it already?? I will take some slow corners on pavement or concrete and listen for the tires to scrub or not.

Yep, just ordered my '08 rear diff cover...should be here before the weekend. I will also be adding Mobil1...heard it already has the LS additive package already in the mix. Did you order the bolt set as well, heard longer bolts were needed with new cover?

I too heard they needed to be longer so I just went to my local NAPA and picked up twelve 1 1/4" long 5/16 18 pitch (coarse) grade 5 bolts. They were like .40 each!!