View Full Version : Timing chain oil seal

08-24-2012, 06:41 AM
This summer I had the rad out and the cooling fan off. While I was in there and had some room, I snugged up the bolts to the timing chain cover - hoping I may resolve a small oil leak from the oil seal around the crank.

Well, that only made it a lot wose...like two or three drip per minute after a drive. Any ideas or suggestions? I find it hard to believe a minor adjustment like that would upset it so much. Is there any hope of "adjusting" this in place without pulling the cover and replacing the seal?



08-24-2012, 06:59 AM
This is just speculation but tightening the timing cover bolts too much may have split the gasket at a bolt hole.

Since the original leak may have been from the seal itself and not the timing cover I think you are more than justified now to pull the cover to fit both a new shaft seal and gasket.

08-24-2012, 07:05 AM
The crank seal and the timing cover gasket are two separate issues. When you tightened the cover, it's possible that you have dimpled it in and caused it to leak in addition to the crank seal. I'm afraid that the best cure at this time would be to just replace the seal and cover gasket. It's not much more work then you have already done. It'll also give you a chance to look at the timing gears and chain, along with the tensioner.

Geo Hahn
08-24-2012, 08:53 AM
I agree and would also just go ahead and replace the tensioner while in there. Would be pretty frustrating to have to open it up again in a few years to replace a $7 part.

As for why -- the front seal is pressed into the cover, possibly your tightening slightly repositioned the seal putting it into poorer contact with the crank.

New lockwashers would (IMO) be prudent upon reassembly and you may as well have the number for the Speedisleeve on hand too in case you find some wear on the crank.

Good time to check the condition of the motor mounts. Also think about a couple of extra shims there if you aren't able to change a fan belt w/o jacking up the engine. And so it goes...

08-24-2012, 04:38 PM
Sage words "And so it goes" from Geo.

Geo Hahn
08-24-2012, 04:57 PM
Sage words "And so it goes" from Geo.

Sage words, but not mine.

They are from a fellow Hoosier (and I don't mean Randall, though I have heard him quote it too).

08-24-2012, 05:19 PM
If the leak is coming from the seal (moss# 520-430), let me ask this.
Did you put the oil seal sleeve (moss # 837-045) on the crank before or after the timing cover was installed ?
"After" is correct because it insures the lips of the seal are tilted inward which makes for a better seal. The procedure is in Bentley.

Geo Hahn
08-24-2012, 05:32 PM
I think it's a TR4A.

08-24-2012, 05:51 PM
Depends on how desperate you are. Something you can try is to clean the area thoroughly (go over it several times with solvent, rag, screwdriver, whatever) where the cover meets the front plate. Then work a bead of RTV into the joint and build it up (kind of like a weld) all around the cover. Use one of the stronger RTV formulas, like gray or black.

Personally, as easy as that area is to access on a 4A, I'd just go ahead and do the cover (including a speedi-sleeve on the front hub if it isn't just perfect). But I have had some success with the RTV method in other cases.

08-24-2012, 05:58 PM
They are from a fellow Hoosier.

I didn't know he was a Hoosier! That explains a lot ...

Another one that I like : "Science is magic that works."

And for some odd reason, this little ditty has stuck in my head all these years:

"Chambers caskets are just fine,
made of sandalwood and pine.
If your loved ones have to go,
call Columbus 690."

08-24-2012, 06:04 PM
I think it's a TR4A.
opps.... you right..

08-25-2012, 05:54 AM
It's definitely the crank seal, not the timing cover gasket. So, Randall, I don't think you meant the RTV method for the crank seal. However, I did use that method with some RTV Black to seal the bottom of my fuel pump in place. It worked great.

What gets me is I only slightly "snugged" those cover bolts. A few were reasonably loose and I barely put any torque on them. Guess I'm pulling the cover at some point.


08-25-2012, 06:45 AM
It's definitely the crank seal, not the timing cover gasket. So, Randall, I don't think you meant the RTV method for the crank seal.

Sorry, you're right, I misread your original post.

There's at least some chance that installing a speedi-sleeve would fix the leak without pulling the timing cover. But by the time you get the hub off, it's kind of crazy not to do the cover as well.

And if it's any comfort, that job is a whole lot easier on a TR4/A than on a TR2-3B; where you basically start by removing the front bumper and work your way back removing everything until you get to the engine.

As to how tightening the bolts made the leak worse, I'm guessing that it moved the cover and seal slightly relative to the hub, which is scored where the seal rides on it. You might even be able to slow the leak by beating on the cover to move the seal a bit more; but I wouldn't recommend it.