I am about to do my rear pinion seal, and I have read up a bunch on this stuff. Now I used a brand new torque wrench that is a 0-60 Inch/Pounds 1/4" torque wrench. To turn the Pinion nut to see what the current preload is.

I have recorded that the pinion preload is between 6 and 8 inch pounds.

The spec for the axle says that it should be 16-29 inch pounds.

My question is, is the preload any different since the cover and gear lube is not in there (it is open and drained currently).

Could this cause the premature failure of the rear pinion seal or any other drive train components?

The pinion seal was redone at ford at about 34k miles, and now is leaking since 50k now i'm at 65k and i'm about to redo this seal.

Finally I don't think it matters, but would the torque reading be off becuase I am using a 1/4" to 3/8" adapter then a 3/8" to 1/2" adapter to fit the 1 1/16" nut?

 

You're only doing the pinion seal, so why do you need to worry about pinion preload? You know to do that you've gotta pull the carrier and ring, pull the pinion, get a new crush sleeve, then compress the sleeve to spec...

Just buzz the old nut off, flange off, pry old seal out, hammer new seal on, flange on , buzz nut back on.



Anyway....couldn't you crush that sleeve some more and tighten the spec up? That is if the bearings are still good?

 

How would I know if the bearing is still good? I mean I could just buzz that nut back on but that is not really the correct way to go about it since that has the bearing preload I'm under the understanding. I am not trying to replace the crush sleeve since it is not crushed too far.

I've read for a quite a few hours on this subject, and it seems very important to set the preload correctly so the axle has a long healthy life. Just like it is important to not use a impact gun.

I am not the kind of person to just ignore details like this, I guess its all the stuff I went to college for making me overthink a bit...

I am going to tighten up the nut more when I do the seal, but i am just wondering could this low pinion bearing preload have been causing my vibration/shimmy I have complained about for a long time, with no answers?

Please, if anyone has insight or comments please let me know.

 

It is VERY important to set that pinion bearing preload properly. Some have gotten away with "just tightening the nut back on", while others (me) did not. Bearings were toast within 50 miles, I rebuilt the right way, no problems in 3-5k so far.

First, the seal may be leaking b/c your preload was so low, you may have already answered your question. Any front and back slack on that pinion? Check that pinion bearing, you MIGHT get away with reusing the crush sleeve since your preload was low, but I would not bother for a few bucks at NAPA. (it's not a Ford only item, I had one from NAPA).

Pull it apart, do it right, and be done with it. Sounds like you know to do it right the first time. I have a post on here about my ordeal, search mine and you'll find it.

No, your adapters should not affect the reading. After reading I would guess that ford did not do it the book way, resulting in the pinion not getting the proper preload. If that 6-8 is with the carrier in place, you are REAL low. That 16-29 is without the carrier.

 

buckgnarly,

First off I would like to say thank you for the quality response.

Secondly, the flange does have play foward and backwards a bit, it does not seem to be TONS, but it does seem like there is play there.

I do want to do this the right way, I have spend so much time working on the truck at this point I want to do everything correct so I can just drive it like the new truck it was once upon 65k miles ago.

So as I am taking it the bearing preload is to be set without the differental being all assembled? To do this, I could just remove the differental shaft pin (large silver pin in the middle of the carrier casing).

Now, the only last question I have is, since i am going to use the bearings that are there since i am not looking to pull tons of the differental apart becuase frankly I am not a mechanic by any means, and I do not have a set of precision measurement tools such as runout gauges and stuff to properly reset gears in the differental.

Is there a different value that I am suppose to be using for the bearing preload?

At this point I am thinking of doing the following:
First: Mark Pinion Flange poisition
1. Remove Pinion Nut
2. Remove Flange
3. Remove Drive Pinion Oil Seal Deflector
4. Remove Rear Pinion Seal.
5. Install Rear Pinion Seal
6. Install Drive Pinion Oil Seal Deflector
7. Install Flange
8 Install New Pinion Nut
9. Torque Pinion nut down
10. Check bearing preload value in inch/pounds
11. torque nut until desired preload value, around 20 in/pounds (since its a number right down the middle).

Again the differental is all assembled, I just pressed in new wheel seals, and polished the pitting/corrosion off of my axle shafts since they kept tearing seals up. I cleaned the drums and have them ready to put on the new drum brake assemblies I did as well since the others were riddled with gear oil.

If I am missing something please let me know. The crush sleeve should be fine to reuse I believe from all the reading I have done since there is not enough preload, it would not be reusable if the preload was correct or over specs.

again, is there a different preload value for used bearings?

 

It's easy, and if your sahfts are out you are half way there.....

EDIT: Forgot, yes used bearings get a different preload! I have it in the garage if you can't find it, but there is a REALLY good Ford racing PDF on the net with all those specs.

1. Take off the bearing caps (MARK THEM LEFT/RIGHT AND UP/DOWN TO PUT THEM BACK IN ORIGINAL SPOT!!!) If you mix them up, you now have a very expensive paper weight.

2. Remove entire carrier. There should be (sometimes more than one) thick washers (shims that set carrier bearing preload) on either side of the carrier, DO NOT MIX THEM UP! Might take a prybar, but it will come out and be careful, it's heavy.

3. Remove pinion (method you stated) and check bearings. My bearings were galled, went south within 50 miles. If yours are galled, then you'll be doing this again for a total rebuild anyway.

Is your axle making any weird noises? Mine had a little whine, hence the galled bearings and leaking seal caused by loose pinion preload.

If bearings are bad, it's time to rebuild...not too hard, but that's another post if you need that....



If bearing are good, reassemble pinion, tighten down using method you said. Crush that sleeve SLOWLY until you get to set preload. I say use a new crush sleeve b/c you'll have it out anyway...in fact, buy a few just in case.....once you go to far, crush sleeve is useless (hence also why you should not do it the half assed "by hand torque wrench" way)

Put carrier back in (might need a little tap to get it in) MAKING SURE SHIMS AND BEARING CAPS ARE IN PROPER SPOTS!. Torque bearing caps to spec (75 ftlbs maybe?)


That's it. If you do not change the bearings, nothing needs to be reset as far as backlash and carrier preload.

You have the inlbs torque wrench, already got the $$ tool. Crushing that sleeve can be a bear, but a good breaker bar, pipe, and pinion flange holding tool (EASY to make) and a steady hand with patience is all you need to do it right. Plus you learn a hell of a lot about diffs, especially the 8.8 and it's PITA crush sleeve.


Ah yes, one more thing....there are reuseable shim kits that can be used instead of the crush sleeve. Idea is to use washers instead of the crush sleeve so you never have to reset it and there is no chance for the crush sleeve to "wear out".
I did not have luck with them, just could not get the right thickness. You may have better luck, but the crush sleeve for me got it much more accurate.

 

If I were you I would not re-use the crush sleeve. If you do you might end up with the same problem you have now.

You can set the pinion bearing preload with the ring gear assembled, but people don't so that the pinion does not knock against the ring gear. Yes, the pinion bearing preload should be set to 16-29 lb-in. The differential bearing cap bolt should be torqued to 83 lb-ft, and the housing cover bolts to 33 lb-ft.

 

Here is the spec sheet....used bearings are 8-14 inlbs...all torques are on last page, rest is for pattern and setup.

http://www.fordracingparts.com/downl...And-Pinion.pdf

 

Could you give me the bearing preload amount for used bearings? That is what I cannot find on the internet. Also if you could link me to that PDF you are talking about, I would love to read that through.

Again, thanks for the quality responses and not just half *** methods to break my truck!

 

beat me to it, thank you !I will check it over later

 

As per the ford service manual, used bearing will get 5 inch pounds more preload than the current reading. 6-8 is probably close you want no more the 15 in-lbs or you risk toasting the bearings.

You must use a new crush sleeve! Don't put the old one back in or you will end up doing the job all over again. 8.8 crush sleeves are very sensitive and once you feel them start to give go very slowly until you achieve the preload, you are wanting.

Also, other little things to be sure of:

Drive the seal in straight; it will last a lot longer if you take you time to seat it correctly.

Next give the seal a little light engine assembly lube or some gear oil to get it's lubed life started.

Other than that this is not a bad job. Just take your time keep track of the side that each shim and cap came off of and you will be golden.

 

I had a feeling it was more than just buzz the pinion nut on and off. Yay! Time to pay someone to do it since I don't have an inch lb torque wrench and I really don't wanna tear the CV axles(Front Diff) out.

 

Thanks again for the information everyone. I changed the pinion seal this early afternoon, and set the preload, The break away is about 14-15 but the spinning preload is at about 10. That is with the axle shafts in and the differental assembled. I actually did not remove the carrier and all that, I opened the front up and checked out what the bearing looked like in there and it looked brand new, and I have had no noise in the rear end just fluids leaking.

I just now have to put the drive shaft back on, and clean all the gear lube up off the housing and brake backing plates... as well as clean up the drums that were filled with gear lube.... haha what a mess... so many red rags used up :)

I will just have to test drive it and see if this solved the problems if not, i'm just going to swap axles because i've got more down time then drive time as of now.

Also, I did not have the special pinion seal setting tool that ford has, so I actually used a minwax 1 quart or is it pint? the small can with teh lid off... it fits the 8.8 pinion seal PERFECT... one time use tool only as it gets crushed up when you hit it with the 3 pound mini sledge to get the seal seated right.

I also used some RTV sealent around the lip of the seal seating flange, I believe there should have been some there.