Pinion Oil Seal - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wxman1 · 07-05-2003, 10:50 AM

Well the pinion oil seal is leaking
on my 69 C10 P/U. I never changed
this thing before, so a friend of mine
let me use an old rear axel off a junker
to play with. I tried to remove the pinion nut
but no dice. I'm using a pipe wrench to hold the
companion flange (where the u-bolts bolt
into) and a 1 1/8 six sided socket on the pinion
nut with a breaker bar.

Is is possibly a left hand thread? Anybody done
this before?

Jim
Mt Juliet

da-burb · 07-05-2003, 01:39 PM

It can take a lot of OOOOMPf to get it off. I have never done it, but what I have read is this....The important part of the entire operation is to get the nut back on the same number of turns as it takes to get it off. Not any more and not any less. This is what sets the depth of the pinion in the ring gear.

*Piston* · 07-05-2003, 04:14 PM

Never tried it by hand... Using a 1/2 impact gun it will come right off. You can use a punch and mark your flange and nut (to return back to the same spot) or go by feel. If you don't tighten it back where it was originaly, your pinion bearings will not have the proper preload which will eventually ruin the bearings and/or Ring/Pinion gears. On the other side... Run the nut down too far and you'll over preload the bearings which will surely make them fail. When you use an impact, you'll be able to feel when the nut makes contact with the flange, start watching your marks from there.

P.S. The correct way to do this is with a inch pound torque wrench! Setting the preload by measuring the amount of force it takes to rotate the pinion.

cableguy0 · 07-05-2003, 05:41 PM

i doubt ur going to get that nut off without an impact gun so its time to call a buddy with an air compressor and a 1/2 inch impact

bmg · 07-05-2003, 06:29 PM

i agree i am pretty big build and i broke my rachet and breaker bar(2' exhaust pipe) you will need air.

Huck · 07-05-2003, 07:38 PM

I had a rear pinion seal replaced on my 91 Chev truck for like $35. a while back. Might be a alternative to doing it yourself to have it done if you can get a good price from a reputable mechanic with the right tools and the experience to not mess it up.
I have found that you can get the pinion nut off with a 3/4 inch socket and pressure bar and a small sledge hammer by giving it a good rap. Good luck~~Huck

lukecp · 07-05-2003, 09:10 PM

I took mine off using a 3/4" drive ratchet. If you find a way to block the rear wheels, you can proably do it. I had to push the ratchet so hard, it started moved the rear tires, and almost caused the truck to roll off the car ramps and land on me. Make sure you block them GOOD.

BTW, i only replaced the yolk on mine, and i didn't replace the seal like an idiot. I later had a shop replace it for me, and it cost $25 for the labor. Alot easier than messing with it yourself.

FrankHoy · 07-06-2003, 12:06 AM

Just did mine today. Did mine just as you are, with 3/4" ratchet & pipe wrench and a couple of cheater pipes for leverage.
It is critical to get the original position marked for the bearing preload. But it can be done without the impact.

07-05-2003, 10:50 AM	#1
wxman1 Senior Member Join Date: May 2002 Location: mt juliet, tennessee, usa Posts: 237	Pinion Oil Seal Well the pinion oil seal is leaking on my 69 C10 P/U. I never changed this thing before, so a friend of mine let me use an old rear axel off a junker to play with. I tried to remove the pinion nut but no dice. I'm using a pipe wrench to hold the companion flange (where the u-bolts bolt into) and a 1 1/8 six sided socket on the pinion nut with a breaker bar. Is is possibly a left hand thread? Anybody done this before? Jim Mt Juliet

07-05-2003, 01:39 PM	#2
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	It can take a lot of OOOOMPf to get it off. I have never done it, but what I have read is this....The important part of the entire operation is to get the nut back on the same number of turns as it takes to get it off. Not any more and not any less. This is what sets the depth of the pinion in the ring gear. __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

07-05-2003, 05:41 PM	#4
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	i doubt ur going to get that nut off without an impact gun so its time to call a buddy with an air compressor and a 1/2 inch impact __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

07-05-2003, 09:10 PM	#7
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	I took mine off using a 3/4" drive ratchet. If you find a way to block the rear wheels, you can proably do it. I had to push the ratchet so hard, it started moved the rear tires, and almost caused the truck to roll off the car ramps and land on me. Make sure you block them GOOD. BTW, i only replaced the yolk on mine, and i didn't replace the seal like an idiot. I later had a shop replace it for me, and it cost $25 for the labor. Alot easier than messing with it yourself. __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

07-06-2003, 12:06 AM	#8
FrankHoy Registered User Join Date: Aug 2002 Location: Des Moines, IA Posts: 154	Just did mine today. Did mine just as you are, with 3/4" ratchet & pipe wrench and a couple of cheater pipes for leverage. It is critical to get the original position marked for the bearing preload. But it can be done without the impact. __________________ 72 Cheyenne 2wd LWB 402/350 CC/PS/PB/AC Tilt/Tach (upgrading to 4X4 402/700R4 CC/PS/PB/AC Tilt/Tach PW/PL) 71 Custom Deluxe 350/350 Tilt/PS/PB 00 Blazer

07-05-2003, 04:14 PM	#3
Piston Account Suspended Join Date: Oct 2002 Location: Olathe, KS Posts: 2,301	Never tried it by hand... Using a 1/2 impact gun it will come right off. You can use a punch and mark your flange and nut (to return back to the same spot) or go by feel. If you don't tighten it back where it was originaly, your pinion bearings will not have the proper preload which will eventually ruin the bearings and/or Ring/Pinion gears. On the other side... Run the nut down too far and you'll over preload the bearings which will surely make them fail. When you use an impact, you'll be able to feel when the nut makes contact with the flange, start watching your marks from there. P.S. The correct way to do this is with a inch pound torque wrench! Setting the preload by measuring the amount of force it takes to rotate the pinion.

07-05-2003, 06:29 PM	#5
bmg Registered User Join Date: Nov 2001 Location: Indianapolis, IN USA Posts: 157	i agree i am pretty big build and i broke my rachet and breaker bar(2' exhaust pipe) you will need air.

07-05-2003, 07:38 PM	#6
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	I had a rear pinion seal replaced on my 91 Chev truck for like $35. a while back. Might be a alternative to doing it yourself to have it done if you can get a good price from a reputable mechanic with the right tools and the experience to not mess it up. I have found that you can get the pinion nut off with a 3/4 inch socket and pressure bar and a small sledge hammer by giving it a good rap. Good luck~~Huck



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