Questions on pinion seal replacement

SVECobraR

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I need a little help here guys and any would be appreciated.

I installed the complete ftbr bushing set and i was going to change pinion seal at the same time. When i was getting ready to loosen the pinion nut i noticed that it was already loose, i was able to loosen it by hand. I decided not to mess with it and take it to a differential shop to get the seal replaced.

After their install i noticed the rear was considerably harder to turn but still movable by hand. fast forward to the test drive and i start to notice a howling from the rear end. At first i thought maybe my toe in the rear was off and the noise was from the tires. But the howling seemed to follow the speed of the vehicle and was pretty loud at 30mph to be tires.

So now I'm thinking do i loosen the pinion nut as maybe the tech put to much preload on the crush sleeve? Which is contrary to what was said in this thread. The posts here recommend tightening on i hear whinning, but this is obvious howling.

Sorry for the typos, its late and my phone sucks.

The pinion seal on my 99 is leaking and i bought a new seal to replace it. But after looking at the ford TIS manual for the procedure it looks like its a little bit more complicated than i thought.

The manual says i should replace the pinion nut and that i have to check the backlash and play on something. I've never setup gears or anything of that kind so any recommendations on this procedure would be greatly appreciated.

thanks in advance.
 
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kxt

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The best method is probably to follow the manual but I have removed the old nut and removed the seal, popped in the new seal, and then put a little thread locker on the old nut and tightened it up to the german torque spec - "goodentight". Never had a problem.
 

SVECobraR

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Thanks kxt, how many miles would you say you've put on it since? I don't see why anything really needs to be set or spec'd but the manual says so.
 

black4vcobra

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I actually did this a month or 2 ago. I didn't get the pinion nut torqued down enough at first and I had a bit of bearing whine. Got it torqued down more and the whine went away.

One method you could use, is to count how many rotations it takes to get the pinion nut off, then when you put it back on, tighten it down the same amount.

This is from a Ranger forum but the process is the same:

How To: Replace Rear Pinion Seal - Ford Ranger Forum
 

Slowerthnyou99

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I would try the count the turns method.... There is a crush sleeve that sets preload on the bearings from the factory... If you over tighten it will crush the sleeve further putting more load on the pinion bearings which will result in overheating, tighten it to little you'll get the whine as stated above.
 

CJK440

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Just mark the nut in relation to the pinion threads. No need to count turns as you will be fully aware the point where all the slack is taken up. (it should be just before the marks line up) Then torque until marks match or go just a hair past.

This doesn't work if you change any component other than the seal.

Sent from my Vortex using Tapatalk 2
 

KLeech

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If your honestly about to guess on anything involving a rearend you deserve the bad things that are going to happen. Just read through a write up and do it right.
 

black4vcobra

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If your honestly about to guess on anything involving a rearend you deserve the bad things that are going to happen. Just read through a write up and do it right.

Well, not everyone wants to (or is able to) have to replace a crush sleeve, replace bearings, and setup a ring and pinion to replace a $10 pinion seal.

Other methods have worked for many people.
 

caveeagle

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Well, not everyone wants to (or is able to) have to replace a crush sleeve, replace bearings, and setup a ring and pinion to replace a $10 pinion seal.

Other methods have worked for many people.

The pinion seal on my '04 cobra started leaking at about 12k miles. It was fixed under warrantly and I would bet you they did not tear down and reset the pinion depth / crush sleeve. For some reason, I did not think to ask them at the time. I just figured it it stopped leaking and didn't make noise, I should be fine.

I had it apart a few months ago to fix a leaking rear cover. (@89k miles) I looked at the wear pattern on the gears. It was wearing a bit towards the outside of the ring gear, but I am not getting any unusually loud rear-end noise, so... back together it went.

Also, there is a torque level needed to crush the sleeve. I have never rebuilt an 8.8, but i have worked on 8" and 9" before. Some recommend setting the pinion preload without the seal in place. Then you get a better estimate of the pre-load. Then you go back and just re-torque the nut with the seal in place. In theory, the torque spec needed for the nut alone should not crush the sleeve. (not totally sure if this applies directly to an 8.8)
 

ibleedblue65

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Personally I wouldn't attempt replacing a pinion seal without doing the crush sleave as well. The crush sleeve sets the bearing preload as stated and once it is crushed once, I don't see how you could ever get the preload and pinion depth right again. Counting threads is a bad idea imo. It may work sometimes but it doesn't make it the right way to do it. You are look ing for bearing preload which is measured in turning torque. Counting threads does nothing to assure you got it right. And yes I have set up a lot of 8.8"s in a professional performance shop.
 

black4vcobra

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Personally I wouldn't attempt replacing a pinion seal without doing the crush sleave as well. The crush sleeve sets the bearing preload as stated and once it is crushed once, I don't see how you could ever get the preload and pinion depth right again. Counting threads is a bad idea imo. It may work sometimes but it doesn't make it the right way to do it. You are look ing for bearing preload which is measured in turning torque. Counting threads does nothing to assure you got it right. And yes I have set up a lot of 8.8"s in a professional performance shop.

My car has a solid pinion spacer instead of a crush sleeve. Does that change your opinion on it at all?
 
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caveeagle

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My car has a solid pinion spacer instead of a crush sleeve. Does that change your opinion on it at all?

It should. A solid spacer will not compress and so you should have no problem replacing the seal without changing the bearing preload. Just be sure you have a solid spacer (should include shims) and not the crush sleeve.
 

ibleedblue65

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My car has a solid pinion spacer instead of a crush sleeve. Does that change your opinion on it at all?


Ya you could just slip a new seal in there, a new nut is a good idea and set your turning torque. When you get good you can do it by feel, but it takes a few.
 

ReefBlueCoupe

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I've done a two, both 8.8s. I count the threads showing on the pinion gear, and also draw a line on the pinion nut and rear end so I can get them lined up the same they were when the pinion nut was removed.

Zero problems out of either.
 

caveeagle

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by: ~blue65
a new nut is a good idea and set your turning torque. When you get good you can do it by feel, but it takes a few.

Hey, blue65, I know that you said you worked at a shop and have done a few of these, but your info seems contrary to some differential basics. I certainly yield you your knowledge on this, but I was hoping you could consider a couple points and validate your take on this.

a) turning torque it determined by the depth of the crush washer (or spacer), right. So In theory, if you change nothing but the seal and don't further crush the spacer (in this case a solid one), there should not be any change to the rotational torque (or pinion bearing preload).

b) the torque force required to crush the spacer/washer is significantly greater than the torque spec for the pinion nut. (I know it is on the 8/9" diffs). So if your pinion bearing pre-load is within spec with the old seal and you do not exceed the lower torque value (nut only), you really should be fine. Yea, I know you could screw it up and over-torque it, but you can screw anything up if you try hard enough.

I am perfectly willing to learn a lesson on this one, I would just like to hear your response on these points. No disrepect intended, but I have often run into professional mechanics that cling to myth and old-school knowledge, rather that a fact based approach to things.
 

SVECobraR

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I do have 4.10's in it. I wanted to replace the stock rear with a torsen T2 anyway, so if it goes it goes and it will give me an opportunity to dial down to 3:73's or 3:90's.
 

mr.speaker

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You guys are making this way to complicated. This is how I do it on rear ends that are fine.

Remove the drives haft bolts (12mm 12 point)
Index the drive shaft with paint or a scribe
Push drive shaft all the way into tranny and hang it with some wire, (you can remove the driveshaft but some fluid will come out of the tranny)
set parking brake (I personally lodge a screwdriver in the rotor to lock it up with the caliper bracket.
With a scribe or paint mark a straight line on the pinion nut,flange,and pinion shaft.
Break loose the nut using a 1 1/16" six point socket.
Count the turns using the painted lines.
You may need a puller to remove the flange. (I always do)
Use a screwdriver or seal puller to remove seal, have something under there to catch the diff fluid.
Install new seal, use a block of wood and hammer to make it flush.
Install flange making sure to line up marks.
Install pinion nut and count the turns and lining up the marks to get it exactly how it was before. I personally apply some Locktite on the threads.
Install driveshaft by aligning marks made earlier, apply some Locktite on the 12 mm 12 point bolts and torque to 83 ft lbs.

It's that simple. Unless there was a problem before with rear, counting the turns of the nut will work fine with the already crushed sleeve.

Also another not, that seal doesn't usually blow out so check the vent to make sure it's clear..I've seen some vent tubes that were clogged with gunk and that pressure would blow the seal.
 

SVECobraR

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Mr. Speaker - Thanks for the comments and directions. I checked the vent a couple of months ago when i removed the diff to replace the bushings and it seemed clear. I'll check it again when i remove the diff for the torsen.

I wanted to know the procedure as i'm taking the car open track racing in 3 weeks and i won't pass tech with a leaky diff and trans.

Thanks again for all the great responses.
 

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