The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-31-2013, 02:00 AM   #1
ol'blazer
Registered User
 
ol'blazer's Avatar
 
Join Date: Jun 2012
Location: edmonton alberta
Posts: 422
Unhappy easiest way to change the rear main seal

so the 350 in my truck has a leaky rear main seal ... im wondering what the easiest to replace it? do i have to pull the trans? or can i get away with just pulling the pan and and back main cap?
__________________
Tyler
------------------------------------------------------
1980 2wd blazer
1985 k10 diesel truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=652276
1987 wrangler 4x4 build-http://67-72chevytrucks.com/vboard/s...d.php?t=663784
ol'blazer is offline   Reply With Quote
Old 03-31-2013, 07:56 AM   #2
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: easiest way to change the rear main seal

Assuming its not a later model engine with a 1 piece rear main seal, yes, you just drop the pan and rear bearing cap to change the seal. No need to drop the trans.
Posted via Mobile Device
Tx Firefighter is offline   Reply With Quote
Old 03-31-2013, 10:12 AM   #3
cdowns
Senior Member
 
cdowns's Avatar
 
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
Re: easiest way to change the rear main seal

easiest way i found was to drop it off at a good shop and pick it up after its done
__________________
71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane

MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF

DONT BELIEVE EVERYTHING YOU THINK

TAKE MY ADVISE;I DON'T USE IT ANYWAY
cdowns is offline   Reply With Quote
Old 03-31-2013, 12:36 PM   #4
ol'blazer
Registered User
 
ol'blazer's Avatar
 
Join Date: Jun 2012
Location: edmonton alberta
Posts: 422
Re: easiest way to change the rear main seal

Quote:
Originally Posted by Tx Firefighter View Post
Assuming its not a later model engine with a 1 piece rear main seal, yes, you just drop the pan and rear bearing cap to change the seal. No need to drop the trans.
Posted via Mobile Device
thanks man!
Quote:
Originally Posted by cdowns View Post
easiest way i found was to drop it off at a good shop and pick it up after its done
something said to be said for doing it that way!, it is easier for sure, but im to cheap to send my truck into a shop for anything.
__________________
Tyler
------------------------------------------------------
1980 2wd blazer
1985 k10 diesel truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=652276
1987 wrangler 4x4 build-http://67-72chevytrucks.com/vboard/s...d.php?t=663784
ol'blazer is offline   Reply With Quote
Old 03-31-2013, 01:25 PM   #5
GASoline71
"I ain't nobody, dork."
 
GASoline71's Avatar
 
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,921
Re: easiest way to change the rear main seal

If it's in the '80 in the Blazer in your sig line... you won't need to lift the engine to get the pan out. Which it a good thing. But... the whole process is a PITA no matter how you do it.

Gary
__________________
'cuz chicks dig scars...

My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread.

The Rebuild of Creeping Death after the wreck

Quote:
Originally Posted by LONGHAIR View Post
I would never rebuild a 305.
Quote:
Originally Posted by prostreetC-10 View Post
I love using vacuum gauges as part of the carb tuning process. I hook the gauge to the inside of my garbage can and leave it there.
Quote:
Originally Posted by Marv D View Post
Remember Murphys 2nd law of mechanical relationships... "OPPOSING COMPONENTS ATTEMPTING TO OCCUPY THE SAME SPACE, AT THE SAME TIME, GENERALLY END UP OCCUPYING ADJOINING SPACE AT THE BOTTOM OF THE OIL PAN"
Quote:
Originally Posted by cableguy0 View Post
Its cheaper to listen to advice given when you ask for help than it is to ignore everyone and wait for carnage.
GASoline71 is offline   Reply With Quote
Old 03-31-2013, 01:42 PM   #6
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: easiest way to change the rear main seal

I don't know about getting the pan off without lifting the engine on his truck.
Posted via Mobile Device
Tx Firefighter is offline   Reply With Quote
Old 03-31-2013, 01:51 PM   #7
GASoline71
"I ain't nobody, dork."
 
GASoline71's Avatar
 
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,921
Re: easiest way to change the rear main seal

I've done a few rear mains in late 70's and early 80's (2 piece) trucks and didn't have to lift the engine. They were all 4x4's as well.

Gary
__________________
'cuz chicks dig scars...

My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread.

The Rebuild of Creeping Death after the wreck

Quote:
Originally Posted by LONGHAIR View Post
I would never rebuild a 305.
Quote:
Originally Posted by prostreetC-10 View Post
I love using vacuum gauges as part of the carb tuning process. I hook the gauge to the inside of my garbage can and leave it there.
Quote:
Originally Posted by Marv D View Post
Remember Murphys 2nd law of mechanical relationships... "OPPOSING COMPONENTS ATTEMPTING TO OCCUPY THE SAME SPACE, AT THE SAME TIME, GENERALLY END UP OCCUPYING ADJOINING SPACE AT THE BOTTOM OF THE OIL PAN"
Quote:
Originally Posted by cableguy0 View Post
Its cheaper to listen to advice given when you ask for help than it is to ignore everyone and wait for carnage.
GASoline71 is offline   Reply With Quote
Old 03-31-2013, 01:51 PM   #8
ol'blazer
Registered User
 
ol'blazer's Avatar
 
Join Date: Jun 2012
Location: edmonton alberta
Posts: 422
Re: easiest way to change the rear main seal

I just tore into it this morning and I got the pan and main cap off without lifting the motor, should have it put back together tonight.
Posted via Mobile Device
__________________
Tyler
------------------------------------------------------
1980 2wd blazer
1985 k10 diesel truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=652276
1987 wrangler 4x4 build-http://67-72chevytrucks.com/vboard/s...d.php?t=663784
ol'blazer is offline   Reply With Quote
Old 03-31-2013, 02:03 PM   #9
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: easiest way to change the rear main seal

Quote:
Originally Posted by GASoline71 View Post
I've done a few rear mains in late 70's and early 80's (2 piece) trucks and didn't have to lift the engine. They were all 4x4's as well.

Gary
I've never done on on a 4x4 personally. I was just going by 2wd trucks.
Posted via Mobile Device
Tx Firefighter is offline   Reply With Quote
Old 05-23-2013, 07:32 PM   #10
GuyO
Registered User
 
GuyO's Avatar
 
Join Date: Nov 2011
Location: Kirkland, WA
Posts: 343
Re: easiest way to change the rear main seal

There's a guy in another thread who takes about making sure the timing mark is facing straight down. Apparently this places the crank in a position where the pan slides out once unbolted. My rear main is leaking like a sieve, and am planning on doing the seal replacement myself. I will let you know about the pan.
GuyO is offline   Reply With Quote
Old 05-23-2013, 11:19 PM   #11
ol'blazer
Registered User
 
ol'blazer's Avatar
 
Join Date: Jun 2012
Location: edmonton alberta
Posts: 422
Re: easiest way to change the rear main seal

Quote:
Originally Posted by GuyO View Post
There's a guy in another thread who takes about making sure the timing mark is facing straight down. Apparently this places the crank in a position where the pan slides out once unbolted. My rear main is leaking like a sieve, and am planning on doing the seal replacement myself. I will let you know about the pan.
i never did that.. but it sounds like a good idea.. tell us how it works, best of luck!
__________________
Tyler
------------------------------------------------------
1980 2wd blazer
1985 k10 diesel truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=652276
1987 wrangler 4x4 build-http://67-72chevytrucks.com/vboard/s...d.php?t=663784
ol'blazer is offline   Reply With Quote
Old 05-24-2013, 08:00 AM   #12
burnin oil
Registered User
 
Join Date: Jan 2013
Location: Eastern TN
Posts: 1,919
Re: easiest way to change the rear main seal

Quote:
Originally Posted by GuyO View Post
There's a guy in another thread who takes about making sure the timing mark is facing straight down. Apparently this places the crank in a position where the pan slides out once unbolted. My rear main is leaking like a sieve, and am planning on doing the seal replacement myself. I will let you know about the pan.
They are trying to make sure that the counter wieght on the crank doesn't catch the pan as it slides back. It is fun trying to get the rear of the pan to clear the trans, baffle clear the oil pump and pickup, and clear the crank all the while bottoming out on the crossmember.
burnin oil is offline   Reply With Quote
Old 05-24-2013, 08:23 AM   #13
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: easiest way to change the rear main seal

I never try to work around the oil pump. I drop the pan enough to get a wrench on the oil pump bolt and drop the pump into the pan.
Posted via Mobile Device
Tx Firefighter is offline   Reply With Quote
Old 05-26-2013, 07:59 PM   #14
SSC's76
No No
 
SSC's76's Avatar
 
Join Date: Jun 2005
Location: Pueblo Colorado
Posts: 1,781
Re: easiest way to change the rear main seal

Quote:
Originally Posted by burnin oil View Post
They are trying to make sure that the counter wieght on the crank doesn't catch the pan as it slides back. It is fun trying to get the rear of the pan to clear the trans, baffle clear the oil pump and pickup, and clear the crank all the while bottoming out on the crossmember.
Yep been there 1st one I ever did lined up perfect second on was like what the heck why isn't this working raised the engine and got the pan off was like hmm that's why. Making sure the crank is lined up properly will make it a easy job unless you are working on a 4x4 the. It don't matter
Posted via Mobile Device
__________________
1976 Custom Deluxe SWB Med FMB.3/4 Drop.
Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out.
1997 K1500 ext cab 5.7 stock except muffler
SSC's76 is offline   Reply With Quote
Old 05-27-2013, 09:21 AM   #15
burnin oil
Registered User
 
Join Date: Jan 2013
Location: Eastern TN
Posts: 1,919
Re: easiest way to change the rear main seal

My 72 K20 isn't that bad. A jack and about 15 bolts gets the 3 piece crossmember out. You can then drop it straight down. Easiest one I have ever done. Pan easy, realligning the crossmember is a PITA due to slight frame twist (old age, not damage)!
burnin oil is offline   Reply With Quote
Old 05-27-2013, 11:23 AM   #16
prostreetC-10
My Carbon Footprint
 
prostreetC-10's Avatar
 
Join Date: Oct 2008
Location: Orygun
Posts: 5,527
Re: easiest way to change the rear main seal

Hopefully you will roll the seal through so it's sticking out an 1/8th inch or so otherwise you might be right back in the same situation. In other words, don't have the where the 2 halves of the seal line up with the 2 halves of the main cap. That is where oil wants to leak under pressure.
prostreetC-10 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:15 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com