How to tell if SBC has 1 or 2 pice rear seal - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-07-2010, 07:29 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
How to tell if SBC has 1 or 2 pice rear seal

I have a Mercruiser 260 HP engine (basically a SBC 350) in my boat that seems to have a leaky oil pan, no doubt from all the years being around salt water. It's a 1985....right around when they changed them, so other visual clues such as valve covers and dipstick locations might not confirm the seal type being used.

To change the pan, I need to jury rig a hoist and lift the engine out of the hold and change the pan with the engine suspended in the air, so it would be nice to already have the pan at that point, rather than to leave the engine suspended for a week or two while the correct pan is on order.

I think I can see under the pan with a mirror and trouble-light, but am unsure what to look for at the back end of the pan. Is any of the rear bearing cap exposed on one and not the other? I've got a feeling nothing is obvious unless I had two engines to compare.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-07-2010, 07:45 PM
hemi joe's Avatar
loves ex cop cars
 
Last photo:
Join Date: Apr 2009
Location: west deptford nj
Age: 52
Posts: 366
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
it's a two piece seal.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-07-2010, 07:49 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,643
Wiki Edits: 0

Thanks: 13
Thanked 56 Times in 53 Posts
Chevy made the change in late 1985 for the 1986 model year.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-07-2010, 07:50 PM
greenmoonshine's Avatar
have a pheasant plucking day
 
Last photo:
Join Date: Oct 2008
Location: Marietta,☠☠☠W.V.☠☠☠
Posts: 159
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The one piece is 86' and later,
Whats your block #?
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-07-2010, 08:26 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Dont know the block number (I'll check if I can find it....not much room in there to look around.....er.....where is it located?). I do have the engine model number, 02608344 and the engine seerial number 6774526, but I'm fairly certain they are both Mercruiser numbers.

The Mercruiser parts list show both oil pans, but you have two know which type rear seal to order. To top it off, Mercrusier discontinued both pans, but Seirra sells an aftermarket of either type. None of the oil pan pics showed enough detail for me to use to ensure which pan I currently have.

But I agree it's probably a 2-piece seal. Just looking for "extra info" to confirm 100%.

Thank-you all for your replies. Sure faster getting a reply on a SBC than a Ford FE......LOL.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-07-2010, 08:33 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 7,723
Wiki Edits: 0

Thanks: 12
Thanked 160 Times in 146 Posts
Block casting # is at the rear, on the block to trans mating flange, drivers side, behind the distributor/drivers side head.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-07-2010, 09:04 PM
Registered User
 
Last photo:
Join Date: Oct 2009
Location: Seattle
Posts: 312
Wiki Edits: 0

Thanks: 0
Thanked 14 Times in 11 Posts
"Chevy made the change in late 1985 for the 1986 model year."

that is also when they changed the valve cover bolts from perimeter to center bolts, should be an instant tell-tale.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-08-2010, 04:47 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Thanks all. I think I`m certain enough that it`s a 2-piece seal to order the proper pan. Trying to get one more month of boating in, I may try some epoxy putty as I found the leak. Right hand side, about 1 inch up and back from the deepest sump portion of the pan.

Original paint on most of the pan except for spots, so I`m hoping the whole think will last another month, or a bit longer. Hole is too small to see, but if I wipe it dry, after about 2 or 3 minutes, a little weepage shows up.

After I get it out of the water, I guess it`s time to fire up the chainsaw and cut some spruce trees for a scaffold of some sort (actually, I`ll use sawn timber and bolts). While I`m at it, I`ll probably get the starter overhauled as it`s another thing that is almost impossible to change with the engine in the boat.

Thanks again.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-08-2010, 05:09 PM
Member
 

Last journal entry: JB's 37 Pickup
Last photo:
Join Date: Oct 2002
Location: Smoky Mountains
Age: 75
Posts: 2,358
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I changed the oil pan on my Mercruiser I/O (302 Ford motor) for the same reason, but I was stubborn and young enough to do it in the boat. I basically laid on my stomach and removed the bolts from the pan. Not an easy task since the salt water had rusted the heads badly. I used three different size sockets:SAE, Whitworth, and Metric in order to get a good bite on the heads. Had to drive most of them on. I placed a mirror in the bilge so I could see what I was working on instead of being totally blind. Having said all this, I would pull the motor.

As a note, if you are planning on keeping the boat a while, try to locate a stainless oil pan. If not, use a very good coating on the new pan and use stainless bolts and lockers

Trees
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-08-2010, 05:27 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Young and stupid? I'm not sure age has much to do with it as I am old and stupid. I replaced my exhaust Y-pipe and didn't remove the engine. I did move it forward about 8 inches, but both bottom exhaust bolts were all done by feel. I couldn't see anything. And laying on top of the engine really adds to being stiff and sore.

Just to change the sparkplugs, I need to remove both batteries, squat down on the battery tray and reach back along the engine. Luckily I have long arms.

The engine compartment looks spacious, but only a midget ...er....."little person" or a small child could get in there.

I actually went to the dollar store and bought a fairly good size hand mirror. I mounted it on a light piece of aluminum channel and then had another piece of channel a little wider so I could hinge it. Helps immensely to find the oil leak. I also tried a digitial camera, but no matter where I thought I had it pointed, all I got was glare from the flash and what is left of the oil pan paint.

Mercruiser has discontinued the oil-pan, and so far all I can find is a Sierra, P/N 18-0613 and a 4 piece gasket set, 18-0411. Wish I could find a pan in SS, but no luck so far. Wish I could find a 1-piece oil pan gasket as well, but again, no luck. Not sure about the pan and gasket compared to a regular SBC, but there seems to be a problem with the dipstick tube. In a Mercrusier, the tube extends all the way to the bottom of the pan for oil removal (has a threaded end up top to connect a oil removal pump). I can't see because of the starter, but I suspect the oil tube is different and somehow partially external to the block so regular SBC aftermarket stuff may not work.

I like your story about all the different sockets you used to fit rusted bolts. I've been there, but luckily not crawling around a boat engine compartment. Does build character though, doesn't it?

LOL

Moral: When you can't afford new stuff, and you buy old stuff, be prepared to work your arse off....i.e. that would be me!
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-08-2010, 06:11 PM
Rickracer's Avatar
ASE Master Tech, Fabricator
 
Last wiki edit: Taurus 2-speed fan control wiring diagram Last photo:
Join Date: Jan 2010
Location: Kissimmee, Florida
Age: 55
Posts: 936
Wiki Edits: 8

Thanks: 0
Thanked 3 Times in 3 Posts
The hole in the block where the dipstick tube comes through is the same, so a 1 piece pan set with the tube on the correct side, and for a 2 piece rear main should fit just fine.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-09-2010, 10:08 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 595 Times in 545 Posts
If you use your mirror and see an aluminum housing like the image below, it will be a 1-piece rear main seal engine.


The housing shown doesn't have the seal installed, but is basically what you'd see bolted to the rear of the engine.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 08-09-2010, 10:12 AM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Ahh.....I see. And if it was a 1-piece seal, I should see some of that casting even with the pan and bellhousing on, and I don't. I'll look again though. Thanks for the pic!
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 08-09-2010, 12:00 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 799
Wiki Edits: 0

Thanks: 2
Thanked 64 Times in 58 Posts
Right 2 piece RMS
Left 1 piece RMS

http://image.highperformancepontiac....uild+crank.jpg

peace
Hog
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 08-09-2010, 10:10 PM
greenmoonshine's Avatar
have a pheasant plucking day
 
Last photo:
Join Date: Oct 2008
Location: Marietta,☠☠☠W.V.☠☠☠
Posts: 159
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Heres a pic I had also

Top is a 1 piece RMS
Bottom is a 2 piece
P.S. I snagged this pic from CarCraft
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installing Rear Main Seal - BBC leejoy Engine 12 02-22-2013 05:51 PM
rear oil seal help alrobjr Engine 5 01-24-2006 07:12 AM
rear seal leak on sbc 350 4onthefloor 2 Engine 9 03-23-2005 03:04 PM
55 chevy, 265 rear main seal slingslingbinks Engine 5 10-19-2004 09:27 AM
400 sbc rear main seal el Engine 2 07-18-2004 09:37 PM


All times are GMT -6. The time now is 02:20 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.