New Oil pan, 350

[1968CHEVYC10]

I'm trying to fix an oil leak on my '75 350, I replaced the oil pan gasket and it's still leaking. So I'm wondering if maybe it's the oil pan, I did a quick google search and found anything from $40 to $280, It's def not a high performance motor so I don't need anything high end but I don't want to buy junk either. The leak may just be from me not putting it in right, the instructions said to just put a dot of gasket maker in the corners, anybody tried something different and had better results? Thanks Yall!

[haysonj]

Originally Posted by 1968CHEVYC10

I'm trying to fix an oil leak on my '75 350, I replaced the oil pan gasket and it's still leaking. So I'm wondering if maybe it's the oil pan, I did a quick google search and found anything from $40 to $280, It's def not a high performance motor so I don't need anything high end but I don't want to buy junk either. The leak may just be from me not putting it in right, the instructions said to just put a dot of gasket maker in the corners, anybody tried something different and had better results? Thanks Yall!

There are two different gasket sets for these oil pans. You have to know which oil pan you have and get the right gaskets. Some gasket sets come with both rubber seals for the end.

[GASoline71]

Post this in the engine and drivetrain section.

But... is it leaking from the front? rear? side rails? High mileage engine?

Gary

[1968CHEVYC10]

Originally Posted by haysonj

There are two different gasket sets for these oil pans. You have to know which oil pan you have and get the right gaskets. Some gasket sets come with both rubber seals for the end.

I'm using a one piece rubber one from fel-pro, is that what you were asking?

[1968CHEVYC10]

Originally Posted by GASoline71

Post this in the engine and drivetrain section.

But... is it leaking from the front? rear? side rails? High mileage engine?

Gary

from the rear, I tightened it down as far as I felt safe doing and still not stopping.

[haysonj]

Originally Posted by 1968CHEVYC10

I'm using a one piece rubber one from fel-pro, is that what you were asking?

You need to lay a straight edge across the back of the pan and measure the depth of the u shape where the gasket goes You probably have the deep pan with a gasket for the shallow pan.

[vectorit]

I've found that there are variations of the tin, as far as the year of manufacture for them. Things can get sloppy if you use a late model timing cover with early style pans, so I always try to keep those two pieces as a "matched set".

Chrome IMO is garbage, and are a PITA to seal.

If you over tighten a cork gasket, you can actually cut it down the middle. Then when the engine gets warm, and the oil starts splashing around it will seep past.

The front and rear areas are typically sealed with a thick rubber gasket that fits into a slot in either the T cover or the rear main, and for me I have always smeared on a light dressing of Permatex Aviation form-a-gasket in the groove. Then in the corners I put a nice dollop of RTV silicone, but wait for the silicone to get tacky before you put a squish on it.

[1968CHEVYC10]

Originally Posted by haysonj

You need to lay a straight edge across the back of the pan and measure the depth of the u shape where the gasket goes You probably have the deep pan with a gasket for the shallow pan.

Ok yeah, I have the right gasket then, I've been through that already.

[1968CHEVYC10]

Originally Posted by vectorit

I've found that there are variations of the tin, as far as the year of manufacture for them. Things can get sloppy if you use a late model timing cover with early style pans, so I always try to keep those two pieces as a "matched set".

Chrome IMO is garbage, and are a PITA to seal.

If you over tighten a cork gasket, you can actually cut it down the middle. Then when the engine gets warm, and the oil starts splashing around it will seep past.

The front and rear areas are typically sealed with a thick rubber gasket that fits into a slot in either the T cover or the rear main, and for me I have always smeared on a light dressing of Permatex Aviation form-a-gasket in the groove. Then in the corners I put a nice dollop of RTV silicone, but wait for the silicone to get tacky before you put a squish on it.

Is there a big difference in the two? I've been using the silicone stuff in the corners. Also The engine was put in the truck sometime between '75-'83 and not rebuilt since then, so I'd guess the timing cover and pan match.

[Lee H]

If it's coming from the rear then it's a bad pan or an incorrect gasket install. After market no name pans are a crap shoot, do not buy a chrome one, they are the worst. If you can not afford a name brand or real GM pan from the dealer then it would be better to get a used GM pan. If it was leaking from the front then it is possibly the wrong gasket and if so it would be pouring out. Up until 1974 the oil pans used a gasket set with a thin front rubber gasket (rubber seal between pan and timing cover), 1975 and newer and most after market pans use the thick version. The only way to know for sure is to measure the depth by placing a straight edge across the front of the pan. 1 3/16 deep uses the 74 and back thin gasket set, 2 ¼ deep uses the 75 and forward thicker gasket set. Just for reference the Felpro one piece part numbers are: OS34509T for '74 & back, OS34510T for '75 through '85 and most after market pans. All pan gasket installs should begin with very clean dry surfaces (clean with brake clean) and a little dab of silicone sealer on the block at the four edges were the rails meet the end gaskets.

[1968CHEVYC10]

So guys I could be a very big idiot... read this: http://67-72chevytrucks.com/vboard/s...d.php?t=408834

I think I confused the rear main with just the part of the oil pan gasket at the rear. So I replaced the gasket and that fixed the leak up front but it's still leaking in the back. I currently have the pan off because I was trying to figure out why the heck it was still leaking, So now I'm wondering if I should go ahead and replace it, or put the pan back on and make sure it's the rear main and not the pan/gasket. Tell me what yall think.

[oldblue1968chevy]

when we did mine i smeared black rtv over the gasket and the corners , maybe just the corners idk it was late!

[john]

looking at pics in previous post. I would say you have a rear main seal leaking. You will have to pull the main brg cap down and replace the seal.

[1968CHEVYC10]

Is there a trick to this? I took out a bolt that looked like it held the oil pump on, but the pump wasn't budging, so I went ahead got the next bolt out, it looks like there's only 3 to get out but I can't get the third one out because the oil pump is in the way.