Pinion seal replacement: pinion shaft line disappeared

1997GT4.6

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Howdy;

I went about replacing my pinion seal on my own today; I was feeling brave. Anyways I marked a white line using an oil based marker to line up the pinion shaft, nut, and yoke for re-installation. So fluid poured out from the diff of course, drenching the shaft. Well the line on the actual shaft disappeared! Not sure how big of a deal this is?

I did line up the nut and yoke perfectly. But I cannot see the mark on the pinion shaft. It had a little bit of play while installing the yoke, is it possible it rotated enough to cause an issue? I did have the parking brake set and the trans in gear, so not much movement should be present if I am correct?

I did count the number of threads showing prior to removing the nut, and have it on with the exact same amount of threads showing again. Should it be okay? I don't have a torque wrench, but I've heard it should be at 15-20lbs. What I do know is that it is tight on there now. When I first removed it, it was so damn loose and with no thread locker.

Cliff notes:
1. Line on pinion shaft erased, but yoke and nut lines are lined up perfectly.

2. Had 4 threads showing on the shaft prior to the dis-assembly, and after installation is also showing exactly 4 threads.

3. Is it possible that the pinion shaft rotated a ton? Curious because I can't see the mark. I did take a picture using flash from above the differential, and there is no mark up there. Parking break was set prior to work, so it shouldn't have rotated much?

Markings prior to removing the nut and seal.
v5xu21.jpg


Pic from about to show no marks on the shaft from above
33tqlo8.jpg



Pic after installation: But can't see a mark on the shaft. Is this important? Should the shaft mark line up to? Or just the yoke and nut? See that tiny little white mark on the bottom of the shaft?? Could that be the remains of the mark? If so, that would mean I'd have to tighten up the nut a TON as it is already very tight. Also, that means the yoke wouldn't line up with the nut and shaft??
wc1sv7.jpg


Help please :)
 

1997GT4.6

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Nobody has replaced a pinion seal? I must be the only one with an old mustang lol.
 

JKady

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What I do when I swap 8.8 pinion seals (Or really any pinion seal) is take a vernier caliper and use the little depth measuring portion (Yeah, technical terms) and measure how much pinion is sticking past the nut and set it back there. Most reliable way to get it back in the same spot in my experience. Never had an issue doing it that way.
 

lwarrior1016

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Ive never done just a pinion seal but I know when you take that flange off, the crush sleeve should probably get replaced because they are one time use and they have to set the correct pinion preload.
 

Dugzy33

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Howdy;

I went about replacing my pinion seal on my own today; I was feeling brave. Anyways I marked a white line using an oil based marker to line up the pinion shaft, nut, and yoke for re-installation. So fluid poured out from the diff of course, drenching the shaft. Well the line on the actual shaft disappeared! Not sure how big of a deal this is?

I did line up the nut and yoke perfectly. But I cannot see the mark on the pinion shaft. It had a little bit of play while installing the yoke, is it possible it rotated enough to cause an issue? I did have the parking brake set and the trans in gear, so not much movement should be present if I am correct?

I did count the number of threads showing prior to removing the nut, and have it on with the exact same amount of threads showing again. Should it be okay? I don't have a torque wrench, but I've heard it should be at 15-20lbs. What I do know is that it is tight on there now. When I first removed it, it was so damn loose and with no thread locker.

Cliff notes:
1. Line on pinion shaft erased, but yoke and nut lines are lined up perfectly.

2. Had 4 threads showing on the shaft prior to the dis-assembly, and after installation is also showing exactly 4 threads.

3. Is it possible that the pinion shaft rotated a ton? Curious because I can't see the mark. I did take a picture using flash from above the differential, and there is no mark up there. Parking break was set prior to work, so it shouldn't have rotated much?

Markings prior to removing the nut and seal.
v5xu21.jpg


Pic from about to show no marks on the shaft from above
33tqlo8.jpg



Pic after installation: But can't see a mark on the shaft. Is this important? Should the shaft mark line up to? Or just the yoke and nut? See that tiny little white mark on the bottom of the shaft?? Could that be the remains of the mark? If so, that would mean I'd have to tighten up the nut a TON as it is already very tight. Also, that means the yoke wouldn't line up with the nut and shaft??
wc1sv7.jpg


Help please :)



I am just about to rebuild my trac loc and put in new gears.
go to late model restoration web site and look up the rear gears section.
you can download a ford pdf that has complete instructions for gear replacement.
pinion seal is one part of that job.

I suggest getting a new pinion nut and crush sleeve and a beam style torque wrench with in lbs.
You also nee a way to hold the companion flange while tightening the pinion nut.
I made one at a friends shop out of flat bar 3/16th thick ss.
they sell cheap ones on amazon that work for any application.
once the nut is tight and the flange is no longer "loose"
you have to sneak up on the pre load.
check it often with the beam style torque wrench
the specs are in the pdf.
different specs for new bearings.

imo counting threads and reusing crush sleeve and nut is just asking for problems

just my take
Doug
 

1997GT4.6

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What I do when I swap 8.8 pinion seals (Or really any pinion seal) is take a vernier caliper and use the little depth measuring portion (Yeah, technical terms) and measure how much pinion is sticking past the nut and set it back there. Most reliable way to get it back in the same spot in my experience. Never had an issue doing it that way.
Yeah I've heard of that method as well. I was actually going to measure it as well but forgot when it came down to it and just counted threads. A couple friends of mine did it that way on their cobra and mach 1 and they are running fine. I've seen countless threads where people do it that way. But after learning more about differentials after doing this, I understand how preload is super important. So now I'm wondering if I should get it checked out by a trusty shop.
Ive never done just a pinion seal but I know when you take that flange off, the crush sleeve should probably get replaced because they are one time use and they have to set the correct pinion preload.
Yeah I have read they are 1 time use but people seem to reuse them. The shop I called even said if it wasn't damaged already they'd reuse it and check preload.
 

1997GT4.6

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I am just about to rebuild my trac loc and put in new gears.
go to late model restoration web site and look up the rear gears section.
you can download a ford pdf that has complete instructions for gear replacement.
pinion seal is one part of that job.

I suggest getting a new pinion nut and crush sleeve and a beam style torque wrench with in lbs.
You also nee a way to hold the companion flange while tightening the pinion nut.
I made one at a friends shop out of flat bar 3/16th thick ss.
they sell cheap ones on amazon that work for any application.
once the nut is tight and the flange is no longer "loose"
you have to sneak up on the pre load.
check it often with the beam style torque wrench
the specs are in the pdf.
different specs for new bearings.

imo counting threads and reusing crush sleeve and nut is just asking for problems

just my take
Doug
Thanks for the information on the pdf! I'm going to download that and read through it.

Yeah, unfortunately when I did it I didn't have any fancy tools so I didn't use an in lb wrench. I did hold the companion flange while tightening the pinion nut and it didn't budge. And yeah the nut got tight, and I definitely had to sneak up on the spot I had marked for original pre load (albeit not the best way to do that). I'm going to see if I can borrow a beam style wrench to check the preload. It should have new bearings if the shop that did my gears used all the new install parts I provided (I say this like that because the shop did some other sketchy things).

Thanks for all the information! I appreciate it!



So update: The rear end sounds just fine. Sounds exactly like it did before I started this endeavor. No, clicking noises and no whines. Only thing I'm hearing is this roaring but I'm not sure its just my tires. Hard to tell when I'm driving and with magnapacks. The roaring was present before I changed the seal. So, that isn't too alarming. But it got me thinking if it should make any sound at all. But the sound progresses as the tires spin faster as well as is the vehicle slows down. It is NOT a whine or any clicking sounds, just roaring like when you have off road tires on a truck roaring. Just in the rear since I have potenzas in the rear and nitto up front.
 

JKady

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The only accurate way to check the preload on the pinion is to remove the axles and carrier and roll it with a dial or beam type torque wrench. Also remember that they're gonna wear in and could likely use a little tightening up with age anyway. Crush collars don't crush as easy as people think, I have to hammer the hell out of them with a 1/2" impact when setting up a diff, you're not going to make an appreciable, measurable difference in preload just re-installing the pinion flange. Also, you're dealing with worn bearings now, if anything a little more pre-load than when you took it apart isn't a bad thing.
 

87hurricane

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I would say you're probably OK on preload if the nut is good and tight. Jkady is right, it takes a surprising amount of force to crush the crush sleeve. As for your roaring noise, its really hard to diag without hearing it. Could be tires, could be a bearing in the rear end, who knows? How did the fluid that came out of your diff look? If it was clear, and didn't have a bunch of metal in it, its probably not your diff making the noise.
 

Dugzy33

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Crush collars don't crush as easy as people think, I have to hammer the hell out of them with a 1/2" impact when setting up a diff


For sure I have seen where people use the impact for install,
but i have also seen where it is not recommended because it can do damage to the bearings and races.
It took me just a few min to make a flange holding tool out of bar stock and drill holes in it.
centerline of the 2 holes was 2-7/16"
for what its worth.
Doug
 

JKady

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For sure I have seen where people use the impact for install,
but i have also seen where it is not recommended because it can do damage to the bearings and races.
It took me just a few min to make a flange holding tool out of bar stock and drill holes in it.
centerline of the 2 holes was 2-7/16"
for what its worth.
Doug

It rattles em a little, I've yet to see a bearing of any kind damaged by an impact short of being outright crushed. Generally when I'm setting up an 8.8 it's it's for IRS explorers and you have to set those up on the bench and even at the dealer we don't have a holding fixture of any kind that would allow you to use anything to hold the flange without the diff flopping all over the place.

The roaring is most likely tires or a wheel bearing going bad. Jack it up and see if you've got up/down play at the wheel.
 

1997GT4.6

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The only accurate way to check the preload on the pinion is to remove the axles and carrier and roll it with a dial or beam type torque wrench. Also remember that they're gonna wear in and could likely use a little tightening up with age anyway. Crush collars don't crush as easy as people think, I have to hammer the hell out of them with a 1/2" impact when setting up a diff, you're not going to make an appreciable, measurable difference in preload just re-installing the pinion flange. Also, you're dealing with worn bearings now, if anything a little more pre-load than when you took it apart isn't a bad thing.
Yeah, not sure I'd trust myself doing all that. Well, actually I probably would. Just would need to acquire the tools and do it right. Well I did get a rebuild kit when I had 4.10s installed so it should be pretty fresh. Thanks for the information, it makes me feel a bit more at ease! So far so good though, not strange noises and I'm enjoying driving it again.

I would say you're probably OK on preload if the nut is good and tight. Jkady is right, it takes a surprising amount of force to crush the crush sleeve. As for your roaring noise, its really hard to diag without hearing it. Could be tires, could be a bearing in the rear end, who knows? How did the fluid that came out of your diff look? If it was clear, and didn't have a bunch of metal in it, its probably not your diff making the noise.
Yeah the nut is good and tight, right back to where it was originally. Yeah after looking at crush sleeves I don't think they're as fragile as people are making it seem. The fluid that came out was normal but dark, there was a small stream of silver metallic particles but it was small. I'm almost feeling like the shop that did my gears reused the oil rather than add new stuff. They seem to do a lot of shady stuff from what I've seen.

I will have a video of the noise for you guys later today when I get a chance to upload it to youtube. After hearing the video it definitely sounds like a bearing or front hub, but I'll let you more experienced folks judge.
We counted the threads when we did my pinion seal. Two years later it's still fine.
Good to hear! Definitely takes away some stress. Thanks for the input!
It rattles em a little, I've yet to see a bearing of any kind damaged by an impact short of being outright crushed. Generally when I'm setting up an 8.8 it's it's for IRS explorers and you have to set those up on the bench and even at the dealer we don't have a holding fixture of any kind that would allow you to use anything to hold the flange without the diff flopping all over the place.

The roaring is most likely tires or a wheel bearing going bad. Jack it up and see if you've got up/down play at the wheel.
Yeah I will jack it up and see how much play there is. Probably a combination of tires and wheel bearings though. A toyota pickup I used to own made a similar noise and the front wheel bearings were burnt and done.
 

JKady

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Metal in the gear oil after break in is completely normal, all the new parts will shed some steel while they wear in.
 

1997GT4.6

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Metal in the gear oil after break in is completely normal, all the new parts will shed some steel while they wear in.
That's what I figured. The initial metal to metal contact will cause some particles to be shed.



Here is a video of the roaring noise. First the camera and mic facing forward then toward the rear of the car.

https://www.youtube.com/watch?v=JO3upWCkGRw
 

87hurricane

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Little late on this, but I couldn't really tell much from the video. If you haven't figured it out yet, get the car up to speed and swerve side to side. If the noise changes, its a wheel bearing, if it remains the same, its probably tires.
 

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