Oil Leak Between Right Chain Housing and Block

[pickupguy]

The engine is a 1976 2.7 S. I have a leak and I can't see where it is comeing from. I have removed the muffler and it appears to be dripping from the nub that sticks out parallel to the ground on the right chain housing. The oil return tubes are dry as are the valve covers. What else is there where it could be leaking from. The surfaces where chain housing mounts to block are dry. Are there bolts or something else inside the chain cover extending thru to the flywheel side of the chain cover? I have looked in my Haynes and Wayne's book and can't find a clear picture. It drips and drips after 2 weeks the oil tank is about 2 qts low. I am not driving it by the way right now as the interior and body are stripped. Any Ideas

Kerry

[curiousone940]

Just a wild guess.....cam tower oil line on the right side???

[pickupguy]

oil lines are tight and dry .... I can't see where it is leaking as the heat exchanger is in the way. The top of teh engine is dry and clean.

thanks
Kerry

[pickupguy]

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[pickupguy]

I pulled the right chain housing cover off and it is filled with oil. Should the oil from the tank drain into the motor as it sits? I noticed that as long as the car ws driven daily it wouldn't leak but if it sits it would leak. Is there a valve somewhere in the oil system that would prevent the oil from draining into the sump? As long as the sump is dry there isn't any oil in the chain housing and it doesn't leak. Now I am even more confused as to the problem

Kerry

[Gunter]

A picture of the "nub" you mention would help.
The oil in the chain housings drains into the bottom of the case thru gravity.
Look closely at Wayne's book page 157-158.
It is possible that the seal and/or O-ring from the sprocket assembly is starting to leak.

[pickupguy]

I think I just found the problem... I removed the right side tensioner and found that the plug on the back of the timing chain housing that the shaft goes into was missing. So as oil would drain from tank into sump the housing would fill up and leak out between the shaft and out thru the hole.


The stupid PO or whoever rebuilt the engine left the cap out of the hole that the cam tensioner shaft slides into.

HE JUST SEALED IT WITH ORANGE SILICONE
AND IT LEAKED
Kerry

[Gunter]

Interesting. Can't remember a plug. Any chance for a picture?
I think the plug you are referring to is actually the shaft itself; they can come loose. It's a press-fit and sealed with JB weld when rebuilding.

[pickupguy]

The parts catalog I thought showed a cap like a freeze plug that was NLA instead of JB Weld the PO used orange silicone



I guess the shaft just goes in with JB Weld sealing the opening

Kerry

[pickupguy]

This is how it was sealed ..... sorry a little out of focus camera won't focus that close



but you get the idea

thank you
Kerry

[theiceman]

which hole was it in ? not sure what it would look like with the tensioner rin ..

[pickupguy]

The big one in the center of the pic. The shaft for the Tensoiner goes in there. Right below the chain.

Kerry

[Gunter]

Kerry:
Couple things:
Make sure you don't lose the cam-timing; I don't see that the chain is tight up (Choked on the cam sprocket)
The shaft normally doesn't come out. You'll need to find a way to make it a tight fit. One way is knurling the shaft befor you smear JB Weld on it and press/push it back in. Knurling is done on a lathe with a special tool; a machine shop will know.
Or, if the play is too much, a new oversize shaft has to be machined.
It all depends on how loose the shaft is. One side of the shaft is in the case only a certain depth, the other side of the shaft is supported by the cover. When it works loose, it can wear out the hole too much.
JB Weld works only with a very clean, clean surface.

[pickupguy]

the shaft is tight once it was pushed back into the hole there was no slop ot movement. I have not moved anything on the motor so when the chain tensioner is reinstalled the timing should be OK. Once it is turned over after the tensioner is installed all the slack should come out. I will be sure to check it before I button it all up. This one really drove me crazy as you couldn't see where it ws dripping from as the exhaust/heat exchanger was in the way. Also the engine never leaked when it was started everyday....but when I pulled the interior out to fix the floors out came tha battery and it wasn't started for 2 weeks the oil drained out of the tank ..... into the sump .... into the chain housing .... out the silicone covered hole. I cleaned everything very well and have JB Welded the shaft in place. Tomorrow I will put it back together and check the chain tension before I put it all together

Thanks
Kerry

[Zeke]

Great find. You've been lucky twice now. The 2nd stroke of luck was that the cam was in a place where a valve spring didn't send it to another zip code AFA the relationship to the layshaft gear. Next time, please tie the chain off so you don't scare everyone here. Halloween or not, loose chains are scary.

[pickupguy]

How would you tie the chain off? I don't understand. I am going to pull the other side as I believe it to be the same even though it isn't leaking so I want to make sure it is done right.

Kerry

[theiceman]

could you not just tie wrap them together till they are tight in the middle of the longest throw?

[Gunter]

Kerry:
Tie up means putting a wire around the chain in such a way that it chokes the chain around the cam sprocket preventing the cam from jumping.
The cams are prone to jump because the cam lobes force the valve springs and that spring force is held in check by the chain tensioners taking out the slack in the chain. No tensioners means: The slack is loose and the cam wants to jump.
You were just lucky this time but, when you remove the left tensioner you may experience a snap meaning: The cam timing is lost!
Tie up the slack before removing the tensioner!
When you open the other side, post a picture of the tensioner before you remove it. We'll be able to tell you if your chain is stretched to the point of maxing out the tensioner travel.
A picture of either side with tensioner installed will do.

[john walker's workshop]

looking at that picture, i would guess that it's already lost. the only engine position that it relatively safe to remove the tensioner and have the cams sit still is #1 TDC, and that ain't where that cam is. don't start the engine until you check and reset the cam timing.

[pickupguy]

the chains are new You can tell that by looking ... the engine was rebuilt 13,000 miles ago by the PO. I have the documentation on the the rebuild.

Kerry