Rear Main Seal Leak? Manual 3 speed 302 1970

[tonytony9]

Hi Everyone,

I am dripping a lot of oil and I believe this to be the rear main seal. I would do it myself, but honestly do not have the time at the current moment. Any tips or recommendations for a type of seal? I am going to have my mechanic take care of it, I will be providing all parts. Is there a complete list of seals I need to purchase anywhere? Clutch and throw out are good so wont be messing with the transmission.

Media Link: https://drive.google.com/drive/folders/1-6Kwdcn7gFUv35qbmVhCxVlCjVMeM018?usp=sharing


Thanks everyone!

 

[Broncobowsher]

I would start higher. Are you sure the back of the intake isn't leaking? It will run down the bellhousing (bellhousing to block isn't a seal) and make it look like a rear main leak.

If it is the rear main. Are there any other engine maintenance issues that should be done as well? Is the timing chain worn out or anything else like that? I say that because I have found it a good idea to just pull the engine, put it on the stand and take care of everything on an engine stand instead of trying to do it laying on your back with oil dripping in your face. Little things like getting the oil pan on nice and clean so it doesn't leak. Yes, it is work to pull the engine, but it makes the rest of the repairs so much easier and often better quality. When you are done, everything is taken care of, not just the one problem.

 

[phred]

The 70’s 302 used a 2 piece seal. Fel-pro bs-30136 I believe is the part number. You will also need an oil pano gasket

 

[Shimmy]

this may help

 

[tonytony9]

I would start higher. Are you sure the back of the intake isn't leaking? It will run down the bellhousing (bellhousing to block isn't a seal) and make it look like a rear main leak.

If it is the rear main. Are there any other engine maintenance issues that should be done as well? Is the timing chain worn out or anything else like that? I say that because I have found it a good idea to just pull the engine, put it on the stand and take care of everything on an engine stand instead of trying to do it laying on your back with oil dripping in your face. Little things like getting the oil pan on nice and clean so it doesn't leak. Yes, it is work to pull the engine, but it makes the rest of the repairs so much easier and often better quality. When you are done, everything is taken care of, not just the one problem.

I recently did the intake manifold seal, using the steal core fel pro gasket. So some of the oil residue is left over from that, did my best to clean it off. So I am pretty positive that is not the issue here.

I would love to pull the engine, not sure how much that is in my court in terms of knowledge, experience or time.

 

[Steve83]

Everyone just assumes that the leak is immediately above the drip - it RARELY is. Every leak on the engine runs down to the oil pan & back to the rear main area, even if it comes from the distributor. Always follow the leak path forward & up to the leak point. Cleaning the engine thoroughly before helps a LOT.

 

[m_m70]

I would start higher. Are you sure the back of the intake isn't leaking? It will run down the bellhousing (bellhousing to block isn't a seal) and make it look like a rear main leak.

This^^

Even if you just did the work on the manifold, I would still clean everything up really good and run some dye in the oil. Have had valve covers leak in the rear look like a rear main.