Another rear seal!!!!
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Another rear seal!!!!
As always with this car. Fix one thing and another pops up. It appears that my second rear main seal is leaking and it got worse when I put the valvoline 50 weight racing oil in it. Does this make since??? The second time with the seal I followed TimAT's direction's to the letter. Did not leak a drop and now it is all over the place!!!!
Could it be something like an over filled pan??? That is wishful thinking as it only starts after the motor is warm and driven down the road. Seems to be able to sit an idle all day long with no leak.....
Could it be something like an over filled pan??? That is wishful thinking as it only starts after the motor is warm and driven down the road. Seems to be able to sit an idle all day long with no leak.....
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
How much oil did you put in it? I have a 5qt pan + the 1 for the filter 6qts total. Unless you have a big pan, 5 quarts is the normal fill including the filter. I'm getting ready to put together a new direction sheet too. The one I did some time ago I've pulled out. Another member sent me a rather heated email telling me I had used "his" pictures of the rear seal package from GM. I'm putting together another sheet. It'll be the same exact steps, with maybe a few more details.
Did you put a spot of RTV at the corners of the pan? And if you pull the oil fill cap off while it's running, can you feel any pressure if you cover the hole with your hand?
Did you put a spot of RTV at the corners of the pan? And if you pull the oil fill cap off while it's running, can you feel any pressure if you cover the hole with your hand?
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
It seems that the leak did become more pronounced when I put the 50 wt in it. I went with this because of the high zinc content. Is this oil so thin it is blowing past the seal????
Tim,
I have the one peice pan gasket and I did not put any sealer on it. Mistake? Also I am not running a pcv. Both VC's have the filter type oil caps that you wash and reuse.
Thanks
Wade
Tim,
I have the one peice pan gasket and I did not put any sealer on it. Mistake? Also I am not running a pcv. Both VC's have the filter type oil caps that you wash and reuse.
Thanks
Wade
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
It helps to use a pcv setup or something positive.
I had no leaks on an 75000 mile engine I hooked up a test gauge on by closing off the pcv and now the seal leaks a bit.
Don't start it up again, just for your reading info.
I had no leaks on an 75000 mile engine I hooked up a test gauge on by closing off the pcv and now the seal leaks a bit.
Don't start it up again, just for your reading info.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Actually straight 50 weight oil is very thick. The Valvoline VR1 oil is also available in a 10W-30 if you care.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
with noonie- a PCV running on vacuum will keep your crankcase pressure down where the seals have a chance. 50w oil is pretty thick for an engine with .003 clearances.
And oil can seep past the corners of the pan where it makes the turn for the block to co over the timing cover and over the rear cap.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
with noonie- a PCV running on vacuum will keep your crankcase pressure down where the seals have a chance. 50w oil is pretty thick for an engine with .003 clearances.
And oil can seep past the corners of the pan where it makes the turn for the block to co over the timing cover and over the rear cap.
YES, no matter what, if you don't use RTV black by permatex....sold in 5 buck tubes any parts house.....you going to have a leak in them corners, never seen a engine that didn't...
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Are you sure your oil leak is not coming from above the rear main seal ? There are many more places that can leak and appear to be the rear seal. I had one in awhile back that a guy had knocked the rear cam plug out.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Guy's after further inspection it is "possible" that it is the pan gasket leaking and not the seal. It is wet where the hump is over the rear cap and it looks to be below the rear cap but hard to tell for sure.
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
You might find this interesting.
When I bought my 77, the oil was clean and felt pretty thick when cold. At least 80° ambient temp here in Florida.
Had the valve covers off, engine cold, ready to adjust the valve running.
Started the engine, to warm it up and noticed that there was absolutely no oil coming off the rockers at all.
It took at least 5 to 10 minutes for the oil to start coming off the rockers after the engine had warmed up enough.
There never was any noise with no oil, tappets were as quiet as any other engine.
Went ahead and adjusted the lifters and changed the oil to 10w40 and left it overnite to cool.
Started the engine cold the next day and there was oil at each of the rockers immediately.
From this observatin, I doubt running straight 50 is a good idea.
When I bought my 77, the oil was clean and felt pretty thick when cold. At least 80° ambient temp here in Florida.
Had the valve covers off, engine cold, ready to adjust the valve running.
Started the engine, to warm it up and noticed that there was absolutely no oil coming off the rockers at all.
It took at least 5 to 10 minutes for the oil to start coming off the rockers after the engine had warmed up enough.
There never was any noise with no oil, tappets were as quiet as any other engine.
Went ahead and adjusted the lifters and changed the oil to 10w40 and left it overnite to cool.
Started the engine cold the next day and there was oil at each of the rockers immediately.
From this observatin, I doubt running straight 50 is a good idea.
Instructor
Joined: May 2008
Posts: 154
Likes: 3
From: Indiana
Guy's after further inspection it is "possible" that it is the pan gasket leaking and not the seal. It is wet where the hump is over the rear cap and it looks to be below the rear cap but hard to tell for sure.
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Melting Slicks
Joined: Nov 2001
Posts: 2,659
Likes: 7
From: Katy (Houston) TX
CI 7-8 Veteran
Blackrat, If you have the PCV connected to vaccume and the filter cap on the other side you will create a vaccume leak! It will suck the air from the filter through the PCV. My 68 was set up like this when I got it and it wouldn't idle till I closed (replaced) the filter cap.
Drifting
Joined: Jan 2004
Posts: 1,991
Likes: 3
From: Piscataway NJ
Guy's after further inspection it is "possible" that it is the pan gasket leaking and not the seal. It is wet where the hump is over the rear cap and it looks to be below the rear cap but hard to tell for sure.
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Here is my plan,
-I should have used rtv on a 1 peice rubber pan gasket???
-If I need to have RTV on it where exactly should it be applied??
- I should be able to drop the pan enough without removing steering linkage correct?
-Connect pcv back up on passenger side and leave the filter style cap on drivers.
-Change the oil to a lower weight Valvoline R that still has the high zinc content.
Thanks All!
Right buy the rear main cap where it meet the block. In the front where the timing cover meets the block.
PVC valve on the drivers side and the breather on the pass.side.
At best remove the idler arm and you can remove the oil pan
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
You had something wrong with your setup then. That is the prefered method for a street car and most problems are actually solved by using this method. If you only have a pcv on one side and no open breather on the other side then you can create a vacuum in the system which can cause the same types of problems as having positive pressure. The open breather on the other side let's the system maintain zero pressure when situations exist inside the motor that give low pressure. When pressure is high then the pcv 'sucks' the pressure out where a breather only setup will not bleed off that pressure and the pressure tries to find other weak points like seals and gaskets to leak its pressure.
There is no reason not to be using a pcv setup on your engine.
Instructor
Joined: Jul 2008
Posts: 123
Likes: 0
From: Allentown PA
DWncchs,
That's what I am thinking may be happening with mine. I just got done replacing the rms using the double lip offset seal and Tim's good instructions and there is still a leak. I cleaned the area up again today, I'll check tomorrow if it is coming from the rear cam plug. The plug is sticking out of the block 1/16-1/8". The first area to get wet with MOTOR oil is inside the bellhousing.
That's what I am thinking may be happening with mine. I just got done replacing the rms using the double lip offset seal and Tim's good instructions and there is still a leak. I cleaned the area up again today, I'll check tomorrow if it is coming from the rear cam plug. The plug is sticking out of the block 1/16-1/8". The first area to get wet with MOTOR oil is inside the bellhousing.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
That's correct. I know of at least 3 different SBC seals. All are under the same number at GM parts, but I think Fel-Pro has them listed separately. I haven't researched BB seal so I don't know if they have more than one.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
The last one I put in was the Blue. This is a BBC also. As far as the cam plug I would not be able to see that unless dropping the trannie BH and cluth\PP would I. And if it were that it would have leaked from the begining and not just started? I guess this is the bad thing about making multiple changes at a time. Hard to figure which one may have caused an issue.
On another note what PCV would you all recommend? I have a cap with one integrated into it but have heard before that the individual ones are prefered.
On another note what PCV would you all recommend? I have a cap with one integrated into it but have heard before that the individual ones are prefered.