COMET CENTRAL

Since I finished my Cyclone I have been chasing an oil leak. I first thought it was the rear seal on the oil pan, I changed the pan gasket to a FelPro one piece unit but the leak persisted.
I found that oil was seeping from between the block plate and scatter shield which led me to believe it was the rear main seal. My clutch has been “grabby” since the beginning so I figured it would be a good time to take a look at it, I removed the trans, scatter shield, clutch, flywheel, and block plate to find the rear main is dry, no oil, no seepage. I did notice that when I removed the flywheel the bolts seemed to have oil on them, I looked into bolt holes and could not see the bottom of the holes so I pushed a punch in the hole and found that I could touch the counter weight on the crankshaft. They were not blind holes! Oil was making its way from the crankcase to the inside of the scatter shield via the threaded holes. (This is a ‘70 Boss 302 block and crankshaft) What makes this strange is that I have never sealed the threads in the past and not had any issues, now I have to use thread sealer/ locker on the threads to stop this problem. I hate it when my car “marks its territory” when I park it. I have also decided to change the clutch to a diaphragm style replacing the long style that was in the car, this change should help with the heavy pedal.
Jim

I did a clutch in my '89 5.0 F150, did everything from the seal out and last time I changed the oil same thing, oil leak at back of motor. You got me wondering cause I didnt seal the flywheel bolts,, I wonder?
Lucky don't have to do a safety unless your pulled over and the cop requests it cause I aint pulling that old bush beater trk apart for a little leak anytime soon!
Sassy was leaking oil past the front balancer fit. I thought it was a seal but when I got in there the seal area was fine but the inside of the pulley was wet,,, broken bolt didn't help though. New bolt and seal we'll see how it goes.

Are the rear oil galley & cam plugs nice and dry, Jim?

Joe

My Dad has a Boss 302 in his 65 Cyclone, I've had a few too. Never sealed the flywheel bolts before but I did have that exact issue in a 428 a few years ago. Here is a picture of my dads motor in his Cyclone

..." so I pushed a punch in the hole and found that I could touch the counter weight on the crankshaft."

How can you see the crankshaft unless the rear main cap has an oil slot in it? Does not make any sense.

Did the Boss 302 have a slot for oil to go to the rear side of the rear thrust bearing like this?



Please 'splain...

Bruce

Joe Travers wrote: ↑

Sun Nov 28, 2021 9:46 pm

Are the rear oil galley & cam plugs nice and dry, Jim?

Joe

Perfectly dry. Although I did have a small leak on the rear of a valve cover.

bmmaurer wrote: ↑

Mon Nov 29, 2021 7:56 am

..." so I pushed a punch in the hole and found that I could touch the counter weight on the crankshaft."

How can you see the crankshaft unless the rear main cap has an oil slot in it? Does not make any sense.

Did the Boss 302 have a slot for oil to go to the rear side of the rear thrust bearing like this?



Please 'splain...

Bruce

You are correct, it was the main cap. The holes in the crank still allowed oil to seep past the bolt threads.
Jim

always sealed flywheel bolts in Fords not a uncommon source for oil leak.

I always remember to seal the bolts,but forget to put on the block plate. usually after the sealer has dried I see the plate laying there,laughin !!

poboyjo65 wrote: ↑

Mon Nov 29, 2021 8:18 pm

I always remember to seal the bolts,but forget to put on the block plate. usually after the sealer has dried I see the plate laying there,laughin !!

poboyjo65 wrote: ↑

Mon Nov 29, 2021 8:18 pm

I always remember to seal the bolts,but forget to put on the block plate. usually after the sealer has dried I see the plate laying there,laughin !!

I too have heard that laugh!
Sometimes ya just have to set everything down and calmly walk out the garage,,, I'll deal with that another day.

poboyjo65 wrote: ↑

Mon Nov 29, 2021 8:18 pm

I always remember to seal the bolts,but forget to put on the block plate. usually after the sealer has dried I see the plate laying there,laughin !!

I pulled that one once but I never sealed the bolts.
Also dumped 5 qts. of oil in the crankcase, forgot to put the plug back into the pan when I was young
There went my beer $$ for the weekend

Joe

Joe Travers wrote: ↑

Tue Nov 30, 2021 9:20 am

poboyjo65 wrote: ↑

Mon Nov 29, 2021 8:18 pm

I always remember to seal the bolts,but forget to put on the block plate. usually after the sealer has dried I see the plate laying there,laughin !!

I pulled that one once but I never sealed the bolts.
Also dumped 5 qts. of oil in the crankcase, forgot to put the plug back into the pan when I was young
There went my beer $$ for the weekend

Joe

My buddy changed the oil in his Kawasaki motorcycle back a few years ago. It was night and he had a pan under the bike while playing loud music. Drained the oil, added fresh oil but didnt have the plug in! drained right back out.
Removed the pan, fired her up and took off to work.
He said it actually ran for about 10 miles on the freeway before it locked up

Joe

comethead wrote: ↑

Tue Nov 30, 2021 1:28 pm

My buddy changed the oil in his Kawasaki motorcycle back a few years ago. It was night and he had a pan under the bike while playing loud music.

Yeah, I was rockin' out when I pulled that one too
Thank goodness I saw it running on my boots before I fired it up!

Joe II

The one time I forgot to check the old filter to make sure the gasket didn't stay on the block is the one time I needed to check. I started my engine and sprayed 5 quarts of Mobil 1 everywhere. This was in the mid-90s when Mobil 1 was 5 or 6 times the cost of conventional oil.

Every other oil change I have checked, and have never seen a gasket stick to the block. But the one time I didn't look...