I have a oil leak in the back of my engine and it was suggested I check the intake manifold. I checked it out yesterday. I felt around it and it has some oil back there but not much. I have a pit in the floor of my shop and I had the truck over it. I got under the truck and looked up. The clutch area is soaked in oil. It is coated in oil between the area between the engine and flywheel, the metal plate between the flywheel and engine, the clutch housing is coated pretty good in oil as well. The clutch seems to be coated as well. The truck probably doesn't have more than 2000 miles on it since I put the good used clutch in it. I redone the truck a few years ago and cleaned it up good. I wish I had known it leaked this bad or I would have changed it when I had the cab and fenders off. So could a lot of oil get into the clutch area and coat it thick like it is ? Its coated good in the clutch area. Its like you poured used oil in that area. On a side note there is not much oil on the outside and towards the top of the clutch housing. It all seems to be concentrated in this area inside where the clutch is.

 

Sounds like a rear main seal, I would clean it all off the best you could and get under it while its running to confirm thats where its coming from. If you dont see it drive it a day or 2 and check again. My clutch area has oil all over to but I got some oil leaks up top.

 

sounds like the rear main seal to me too. Had this problem on my 64. Its somewhat of a pain to replace also. You could either loosen up the crank and use a special rear main seal puller like i did or if i were to do it again i would pull the crank and put a neoprene seal back in instead of the rope seal.

 

Get a light and mirror, valve covers and intakes are problematic with FEs not rear main seals.





John

 

I was in a hurry to get finished yesterday and didn't get a mirror. I checked as the best I could yesterday but I went out there tonight to look at it with a mirror. I saw the gasket area there and it does have oil on it soaked. But it is not dripping or running down the bell housing the best I can tell. Is there big enough opening between the bell housing and the engine for it to run in there? The odd thing to me is the flywheel is soaked but the outside of the bell housing is clean. As far as the intake manifold goes what do you have to take off? It looks to be the intake and the valve covers only,is that correct? I Think I may start with the intake manifold and if it still leaks look towards the real seal next.

 

You have to pull the valve covers, unbolt the rocker shaft and remove the pushrods.

 

As far as the truck goes it was rebuilt in 83. I drove it every other weekend for three years until 86 then I drove it for a year or so every day. Then I parked it around 88 and then reworked it around 90. The engine had about 40k to 50k then on it. It still run good. I drove it off and on for about ten years. I probably put no more than 10k on it then. I then began to redo it a second time around 2001. I then got it reworked around 2006 and it ran good then as well. It runs fine just looses the oil. It hasn't been rebuilt since 83 but probably has less than 70k on it. It runs fine just leaks. I was wondering about these kits you get like slick 50. Do they do any good or will they make stuff worse? I plan on redoing the intake maifold anyway but was wondering if they could recondition the other seals and gaskets.

 

I wouldnt put that crap in my motor. If your doing the intake and valve covers anyways I would just do that and see what happens. Dont forget a new distributor o ring, I have oil all over because the po forgot it when they did the heads. The only oil additive ill put in my motors is lucas oil stabilizer or z max, yes z max dose work, ive seen it do wonders lol.

 

It sounds like a rear main...another common problem is the rear intake seal getting squeezed out...or in...also the ends if not sealed amply when intake was installed can be the culprit as well...wipe the area down really good at the rear of the intake/top of block...carb cleaner is good...cover the cab or other areas you dont want paint to get messed up...or just douse a rag with it and wipe till clean...same at rear of heads...and the lower part of the crankcase with the inspection cover off...clean it out totally as well...Park the truck on a steep grade pointing uphill and see what happens...if the rear main is leaking...that will show up quickly...
As for oil on the clutch stuff...a soaked clutch is a worthless clutch...also note...just to be positive if its 10/40 or 10/30 or 90w gear oil...
Pray its a intake or valve cover or oil pan leak...if it IS the main...IMO, for it to be thoroughly cleaned and prepped for resealing I would pull the engine as you would be disturbing the rotating assembly...Ive seen how its told to be done in the shop manual...not a fun job by any stretch...and what if you go through all that and it still leaks...or is worse...its a ton of work I know...but you know it will have the best shot at being cured...that is assuming it is the rear main...as I said...hope like heck its not this seal leaking...


- cs65

 

*****, When the truck is moving down the road air flow comes in the frontal area across the the engine and when it gets to the firewall it is forced down. Any leaking oil has to follow this flow pattern.

You don't by chance have chrome valve covers do you, they are the pitts when it comes to leaking.

I have to confess I can't install valve cover gaskets and they not leak. I have fought that battle several time over the last 40 years, because I always have had a truck with a FE in it.

If you see a wet area, you see your problem.




John

 

had the same problem with my "66. Tried the intake, valve covers and still leaked. Changed the rear main sealwith the engine in the truck. Still leaked, took the engin out to change rear main seal again thats when i discoverd the rear oil galley plugs popped loose. They are like little freeze out plugs around the back of the block around the cam shaft. inexpensive fix just lots of work. Good Luck

 

I have the original covers on the engine, not chrome. I have noticed something odd with it. If it is driven a lot or often it doesn't do it as bad. I drove it camping this summer to about a hour away. It didn't leak as much. But if I pull it out of the garage and to the yard it leaks more. The more its driven the less it will leak. I wonder if it is just the seals old and need to be driven more. I get the high mileage oil for it hoping it has conditioners in it. I will play around with it some more to see what happens.