C5 rear main seal technical question?
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
C5 rear main seal technical question?
Heres the rear main seal replacement procedure right out of ESI:
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Yea,,,thats my thought process also but,,,,,I want to know why the GM procedure says NOT to do it.
Only thing that I can think of is that it needs to lap it self in.
BC
Only thing that I can think of is that it needs to lap it self in.
BC
Racer
Joined: Jun 2009
Posts: 326
Likes: 0
From: Texarkana TX
I could see that if it's a pretty hard nonpliable seal. I've used both GM and FelPro rear seals oiled with no issues. I've always been more concered with alinement issues than anything. Good luck with the build.
Chuck
Chuck
Racer
Joined: Apr 2009
Posts: 359
Likes: 25
From: San Antonio TX
Its a different material from what the older chevy motors used, and doesnt work right with oil on it. I cant give you the exact reasons, but Ive done it both ways and never had one leak, so take that for what its worth. Although it may be easier to get it on with a little bit of lubrication around the crank/seal.
Melting Slicks
Joined: Dec 2003
Posts: 3,315
Likes: 17
From: Near Jacksonville Fl.
I always use vasoline on the lip of the seal, in the last 45 years I've never had a seal leak on the lip side unless the the sealing surface was damaged.
And that was because the customer was to cheap to do the repair correctly!
Tech Contributor
Joined: Jan 2007
Posts: 19,471
Likes: 1,171
From: Dyer, IN
Heres the rear main seal replacement procedure right out of ESI:
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
PTFE seals are self-lubricating, and require a clean surface for correct installation. Oil or grease is permissible with older type elastomer based seals, which is why so many of these old school guys just love the vasoline.
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Its getting installed in a sterile environment!! That will be the cleanest crank sealing surface on the planet.
Thanks for all the replies
Bill
Thanks for all the replies
Bill
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Advanced
Joined: May 2010
Posts: 92
Likes: 0
From: Virginia
Heres the rear main seal replacement procedure right out of ESI:
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
Crankshaft Rear Oil Seal Replacement
Tools Required
J 41479 Crankshaft Rear Oil Seal Installer
Removal Procedure
Remove the engine flywheel. Refer to Engine Flywheel Replacement .
Gently pry the crankshaft rear oil seal (1) from the rear cover.
Installation Procedure
Important
Do not lubricate the oil seal inside diameter (ID) of the crankshaft surface.
Do not reuse the crankshaft rear oil seal.
Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface.
Install the J 41479 cone (2) and bolts onto the rear of the crankshaft.
Tighten the bolts until snug. Do not overtighten.
Install the rear oil seal onto the tapered cone (2) and push the seal to the rear cover bore.
Thread the J 41479 threaded rod into the tapered cone until the tool (1) contacts the oil seal.
Align the oil seal onto the tool (1).
Rotate the handle of the tool (1) clockwise until the seal enters the rear cover and bottoms into the cover bore.
Remove the J 41479 .
Install the engine flywheel. Refer to Engine Flywheel Replacement .
WHAT IN THE HELL does this contraindicative jumble of words want us to do????????
" Lubricate the outside diameter (OD) of the oil seal (1) with clean engine oil. DO NOT allow oil or other lubricants to contact the seal surface.
Lubricate the rear cover oil seal bore with clean engine oil. DO NOT allow oil or other lubricants to contact the crankshaft surface. "
WHY don't they want lubricant on the SEAL LIP or CRANK Sealing surface???? That goes against everything I ever been taught about seal replacement.
Can someone explain this?
Thanks
Bill
Last edited by Speedracer73; May 19, 2011 at 10:03 AM. Reason: Update
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Boy,,, I sure can!
To get to the seal you have to drop the ENTIRE drive train from the bell housing back, remove the Clutch, Fly Wheel and the rear cover on the engine. Install the seal
Then reverse the procedure. I bet you it will take you DOUBLE the time if you were to do it your self!! Pluss all the parts that you dont see like new flywheel bolts etc!!
BC
To get to the seal you have to drop the ENTIRE drive train from the bell housing back, remove the Clutch, Fly Wheel and the rear cover on the engine. Install the seal
Then reverse the procedure. I bet you it will take you DOUBLE the time if you were to do it your self!! Pluss all the parts that you dont see like new flywheel bolts etc!!
BC
Advanced
Joined: May 2010
Posts: 92
Likes: 0
From: Virginia
Boy,,, I sure can!
To get to the seal you have to drop the ENTIRE drive train from the bell housing back, remove the Clutch, Fly Wheel and the rear cover on the engine. Install the seal
Then reverse the procedure. I bet you it will take you DOUBLE the time if you were to do it your self!! Pluss all the parts that you dont see like new flywheel bolts etc!!
BC
To get to the seal you have to drop the ENTIRE drive train from the bell housing back, remove the Clutch, Fly Wheel and the rear cover on the engine. Install the seal
Then reverse the procedure. I bet you it will take you DOUBLE the time if you were to do it your self!! Pluss all the parts that you dont see like new flywheel bolts etc!!
BC
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Thanks Bill. This is the car that had the broken vacuum lines due to battery acid leaking last year. It has been in my garage the whole time. I did not notice any leaks under the car. Once it gets to the shop, now they are saying the rear main seal is leaking. Could the seal have dry rotted and when they started the car, it started leaking or would it have leaked while in my garage. This particular project is estimated at $1500 so it behooves me to make sure whether or not I need to get this done or not.
Have them look reeeeally close at your EOP sending unit. If it leaks/seeps enough, oil WILL drip/run down, usually over the bell housing but it's possible some may have gotten inside as well. It's possible some "tech" did a quick visual and made an incorrect snap-decision as to what he saw and "diagnosed" a rear main seal leak.
Also possible they know it's an EOP sensor of course and are merely trying to fatten their repair bill. That's where the integrity or trustworthiness of the shop (or lack of) comes in to play.
Burning Brakes
Joined: Jul 2007
Posts: 881
Likes: 2
From: hill billy hell
seems like a good place to ask, anyone come across the forge plug in the crankshaft
leaking making it appear as though it was the rear main seal that was leaking?
Just trying to get a feel for the odds of that happening.
Have read about guys damaging the plug trying to remove the pilot bearing.
leaking making it appear as though it was the rear main seal that was leaking?
Just trying to get a feel for the odds of that happening.
Have read about guys damaging the plug trying to remove the pilot bearing.
Advanced
Joined: May 2010
Posts: 92
Likes: 0
From: Virginia
Your rear main is not "dry rotted".
Have them look reeeeally close at your EOP sending unit. If it leaks/seeps enough, oil WILL drip/run down, usually over the bell housing but it's possible some may have gotten inside as well. It's possible some "tech" did a quick visual and made an incorrect snap-decision as to what he saw and "diagnosed" a rear main seal leak.
Also possible they know it's an EOP sensor of course and are merely trying to fatten their repair bill. That's where the integrity or trustworthiness of the shop (or lack of) comes in to play.
Have them look reeeeally close at your EOP sending unit. If it leaks/seeps enough, oil WILL drip/run down, usually over the bell housing but it's possible some may have gotten inside as well. It's possible some "tech" did a quick visual and made an incorrect snap-decision as to what he saw and "diagnosed" a rear main seal leak.
Also possible they know it's an EOP sensor of course and are merely trying to fatten their repair bill. That's where the integrity or trustworthiness of the shop (or lack of) comes in to play.
