Replaced pinion seal but did I do it right?

[BigRandy]

Originally Posted by YoungPup1977

by any chance when you had the pinion seal out, did you pull the front pinion bearing out to see if it was bad along with looking at the front pinion bearing race in the housing....the whine could be a bad bearing going south on ya....

with the leaking seal, maybe the axle "wheel" bearings were not being lubed the way they should be and ya got a bad wheel bearing....just a thought.

I would suggest to take the rear cover off, and pull the axles and pull the carrier, along with pulling the pinion out of it to inspect the bearings....a bad bearing should show its ugly arse.....this way you would know for sure before spending 300 bucks for used stuff...a bearing/gasket/gear oil may only cost ya 50 bucks...seems to me if cash is a issue this would be the chosen path....only labor on tearing it a part and if there is no bad bearing....option B.....

Good info.

I'm not planning a swap until I've had a look inside and verify what's what. If it is hosed I'd take a shot at fixing it myself if I had a way to press the bearing off. I could always see if one of the shops would do it.

I've been around part swappers most of my life and really don't like replacing anything can be fixed as long as it's done right. Lots of people I know start replacing things without understanding them. I'd much prefer to fix the rearend than replace it but will have to see what I have to work with.

The money really isn't a huge deal - not at the moment anyway. I'm just not one to spend much on my hobby when I don't have money coming in.

[YoungPup1977]

so I guess you didnt check the front pinion bearing and race when you pulled the pinion seal out....with noises (whine) when letting off the gas vs noise (whine) getting on the gas mean different bearings could be defective......either pinion or carrier bearings, so once you have taken the carrier and pinion out of the housing, you can take them to a machine shop to have the bearings pressed off....again its easy for me to spend other peoples money but I would replace all the bearings meaning I would spend your money and buy the bearing kit to replace all bearings in this differential....GOOD LUCK !!!!!!

oh yea, I almost forgot the other reason for replacing the gears for a higher gear ratio to save on gas....I think you just fix the noise and forget about spending the money on getting different gears...454 CID, no matter what gears you use will only yield 12 miles to the gallon if you are lucky, if you use this truck as a daily maybe a honda is in your future....keep the truck for weekend activities....just an opinion, just like what we all sit on, everyone has one...

[BigRandy]

Originally Posted by YoungPup1977

so I guess you didnt check the front pinion bearing and race when you pulled the pinion seal out....with noises (whine) when letting off the gas vs noise (whine) getting on the gas mean different bearings could be defective......either pinion or carrier bearings, so once you have taken the carrier and pinion out of the housing, you can take them to a machine shop to have the bearings pressed off....again its easy for me to spend other peoples money but I would replace all the bearings meaning I would spend your money and buy the bearing kit to replace all bearings in this differential....GOOD LUCK !!!!!!

oh yea, I almost forgot the other reason for replacing the gears for a higher gear ratio to save on gas....I think you just fix the noise and forget about spending the money on getting different gears...454 CID, no matter what gears you use will only yield 12 miles to the gallon if you are lucky, if you use this truck as a daily maybe a honda is in your future....keep the truck for weekend activities....just an opinion, just like what we all sit on, everyone has one...

I did not check the bearings. Just tapped the new seal. Hindsight being what it is I know now that I should have. The whine is at speed when warm. It stops when I let off the gas.

My other truck is an F150 that stays parked most of the time. Not exactly sure why, but I just prefer driving the old Chevy for short trips. No Hondas for me.

The MPG isn't a huge concern. I can live with 10 and it will do that if I keep my foot out of it. Years ago I had a 73-454 and it got 11. I don't remember what gears it had but I do remember it got 11 most of the time and didn't seem to care if it was loaded or not. They may not have a ton of HP but they pull like a mule.

As soon as the temps drop back to double digits I'll pull the yoke and check the bearings. Thanks.

[Bigdav160]

The pinion bearings are pressed on to the pinion. There is no way to "inspect" the bearing without removing the pinion. At that point you are at least reconditioning the axle.

Was the whine there before the seal replacement? Then likely you had a bearing problem combined with the leak. Pinion bearings spin fast and are lubed by splash lubrication. They starve for lube when the axle is run low.

If the whine started after seal replacement it's likely the pinion bearing preload is off. Those tapered bearings are not tolerant of too much preload (nut too tight) and too loose they let the pinion walk back and forth messing with the meshing of the ring gear and pinion.

[YoungPup1977]

The front pinion bearing is not pressed on......

[Bigdav160]

Sure it is. But not as tight as the big bearing. It has to be to keep the inner race from spinning on the gear.

BTW, I am an old pup.

[YoungPup1977]

Originally Posted by Bigdav160

Sure it is. But not as tight as the big bearing. It has to be to keep the inner race from spinning on the gear.

BTW, I am an old pup.

Dont let the name fool ya...

So how do you PRESS the front bearing on when you install the pinion gear thru the housing ? The bearing has to slide onto the pinion NOT PRESSED on....

BTW, I am a experienced PUP.....

Its a tight fit for sure, but its not a PRESS ON fit......when he had the pinion seal removed he could of removed the front pinion bearing and inspect it along with the bearing race.....no press needed to remove this bearing....please dont confuse the situation.. thanks...

[Bigdav160]

Once the ring gear and case are removed does the pinion fall out?

No, you have to drive it out.

When reinstalling you have to use the yoke and nut to drive the front bearing back on the gear. It doesn't just slip on.

No disrespect meant. I was a transmission man at GM dealers for 15 years before I retired to teach auto repair.

[YoungPup1977]

Originally Posted by Bigdav160

Once the ring gear and case are removed does the pinion fall out?

No, you have to drive it out.

When reinstalling you have to use the yoke and nut to drive the front bearing back on the gear. It doesn't just slip on.

No disrespect meant. I was a transmission man at GM dealers for 15 years before I retired to teach auto repair.

Now you changed it from pressing to driving the bearing off. Which is it

I can get the front bearing off without taking the carrier out. Now lets see who jumps on this band wagon.....

[BigRandy]

I'll explain it the best I can how I got where I am.

During a 30 minute to the Lowe's I noticed something didn't sound right. It was very faint so I wasn't even sure if I was hearing it for the first time or if it had been doing it earlier, but I've got 31x10.50's on it and they are a little rough so I thought maybe I had a low tire.

I checked them at Lowe's and they were fine, but when I backed out of my parking space I saw a puddle of oil about 3" across. I got out and looked and the pinion seal was dripping oil. I went abt 2 miles to the nearest Autozone and bought a quart of house brand gear oil and crawled under it right there in the parking lot where it took about 2/3 of the bottle. During the drive home it lost maybe 2-3 ounces. It stayed parked until the next day when I got a new seal.

I pulled the driveshaft and marked the nut, yoke and housing with a chisel and counted the exposed threads. I expected the nut to be tight so I sprayed it with lube and removed it with an impact. It wasn't loose but didn't put up a fight either. About like removing a lug nut.

When I put it back together I used a ratchet until the marks were lined up with the same number of threads showing. Felt to me like it went on way to easy. Just barely snug but not tight.

Good, bad, or otherwise, I used an impact to run it down about 1/2 or 3/4 of a turn where it stopped. It's tight. Can't budge it with a ratchet. Checked the oil and took it for a drive. It seemed okay but after about 15 minutes I noticed the whine again. Only does it under load but stops as soon as I let off the gas.

I don't know if I hurt it by running it almost a quart low or if I screwed up the preload when I put it back together, but I find it hard to believe that running it the way it went back together using a ratchet could have been good. As easy as that nut was to line up I could have put it on with a 1/4" drive ratchet.

I've worked on engines and machinery for years but never touched a set of gears. I'm not afraid to pull the gears and drive the pinion shaft out but getting it back together right would be new ground for me.

I could have a shop press new bearings on the shaft, but getting the clearances correct during reassembly might be trial and error which is why I thought about a complete swap. I'd prefer to fix it rather than replace it but with my lack of experience with diffs this may not be the time to experiment.

I think I'm hosed.

[homemade87]

Originally Posted by Bigdav160

Once the ring gear and case are removed does the pinion fall out?

No, you have to drive it out.

When reinstalling you have to use the yoke and nut to drive the front bearing back on the gear. It doesn't just slip on.

No disrespect meant. I was a transmission man at GM dealers for 15 years before I retired to teach auto repair.

This is correct , The bearing will not come out without driving the pinion to the rear . This is why when setting up a gear most will hone out the small bearing to easily remove it and not have to hammer it out . Some will also hone a new large bearing as well to to make it easy to change shims when setting it up .

You can not get the small bearing out with a assembled differential .

[YoungPup1977]

Here is a pic of removal of a front pinion bearing on a Chevy truck 12 bolt. Notice in the pic the carrier is still in the differential housing. Please educate me on how this can not be done. Tapped that bearing out with no major beating/driving required. I have 10 more rear ends here in my shop. You want a video on the HOW ?? Maybe stop by the shop along with all the students showing up this Friday to see a differential be rebuilt You might learn some thing. How’s that for all you ego pushers. Lol !!!!

[YoungPup1977]

Here is a different angle to show the axles are not removed or the carrier. No press required. This differential has been in a 1972 c10 for several years, I pulled it out to install it into my 1972 Blazer 4x4 to 2wd conversion project. back to the real reason for posting this, once the front pinion bearing is removed (slip/slide/whatever words you want to use) you can inspect the bearing and the race for any wear/pitting/etc to see if its bad....if bearing is bad, than I would consider pulling the entire differential a part to check all parts for wear....

but what really is going to happen here is a total replacement of the differential housing... replace the existing differential with some USED BS.....300 bucks....oh yea thats cheap....

just think if only the front pinion bearing is bad....all that work R&Ring the complete differential for what a 20 dollar bearing and race...and I thought this was a "cheap way" forum....

[Mike C]

Interesting. I've rebuilt probably 30 different axles and I don't think any of them would let me get the front pinion bearing out without driving the pinion. Maybe some of the absolutely worn out ones. Some of them require absolutely hammering the F out of it. Put the nut on a few turns and use a 3/4" brass drift to drive in the center of the pinion until it slips. Then you can remove the nut and the pinion.