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Leaking timing cover

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TulsaFred

TulsaFred

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When I reassembled the 1275 I was concerned about oil leaks from the rear, and the proper alignment of the "eyebrow" piece.
As it happens, the rear seems nice and dry, but I have a goodly oil leak from the front, dripping off the sawtooth timing marks/flange.
I suspect the leak is from the front seal in the timing cover.
Can someone give me specifics on how to properly fix?

thanks
Fred
 
I put them in with a little smear of red loctite on the OD of the seal, and make sure you don't use paint or any interior engine coating on then inside of the cover where the seal sits, it can cause it to slip out of place. Then a biggie is to put grease on the seal's lip to keep them from getting torn during initial use and installation. last resort get a Speedi Sleeve for the harmonic balacner to give the seal a new surface to ride on.
 
make sure its not leaking out from the press fit of the breather, mine came loose there and was dripping a bit.
 
The other item not often mentioned is to "center" the timing cover seal over the crank snout. I do this by using an old crank pulley from an 1098 that has been polished on the ID to be a slip fit over the crank snout. Also open the keyway a bit with a file to slide on nicely. This allows the timing cover to be centered before bolting down and creating the final seal. This way the rubber seal is centered with the harmonic balance seal surface.

HTH,
Mike Miller
 
Mike,

I'm not sure I follow. It makes sense to keep the timing cover bolts loose until the pulley goes on then jiggle and center it before tightening down the bolts. None of which I did.

However, what do you do exactly with the spare 1098 pulley?

Also, I noticed there is what appears to be a rubber "o-ring" embedded on the backside of the balancer/pulley. Mine was kind of dry rotted. Can it be renewed?

The breather can is snug, the leak is definitely from the crank seal.

BTW, on my motor the breather hose from that vent can (oil separator?) goes to a Y-connector and then short lengths to each carb. There is no PCV or any other valve or restriction. Could this be sucking oil into my intake?

Thanks!
Fred
 
That "o-ring" you mention is probably not an o-ring. Harmonic balancers are typically made by molding a layer of rubber between two steel cylinders. It's a Catch-22 situation. If you mess with the dry rotted rubber you may weaken what remains. If you don't mess with it, you will worry about it. Regardless, it is not something you can fix at home. Repair is by replacement. While personally I have not seen a failed harmonic balancer I have heard horror stories of what can happen when the rubber fails and they come apart. Hopefully Hap will post again with warnings and guidance on when to replace a harmonic balancer.

Mike already posted what I was going to suggest about leaving the cover loose until it is centered on the front pulley.
 
I never tighten the bolts on a timing cover unless the crank pulley is in place. I always let the new seal align the cover. I also use the grease method on the seal lip as Hap suggests. PJ
 
Back from racing in Memphis.

Actually it is only the 1098 crank pulley mounting hub. The 948/1098 crank pulley is just stamped steel halves riveted to a mounting hub. I grind off the rivet heads and separate the pieces. I then have lightly honed out the ID of the hub and enlarged the keyway to more easily slide onto the crank noses. I use this "tool" to center the timing covers on the crank nose. Because the hub doesn't overhang the T/C, this allows me to bolt down the timing cover using my ratchet and an extension with appropriate socket on all bolts. Saves a little time for me since I'm building/rebuilding a dozen or more engines a year. Also, I am taking the 1275 style balancers on and off multiple times to get the clearance on the backside right. I've modified these to use the toothed trigger wheels for Electromotive "Wasted-Spark" ignition systems (HPV/HPX type) and I have to space the balancer/dampener out a little from stock location.

I often encounter stripped 1/4" threads in many of the front plates. So, I'll thread in a bolt from the rear for the two bottom bolts and one under the water pump inlet. Then weld the head to the plate and grind the head down for clearance to the block and pan. Then I'll also use a trimmed 1/4" fender washer on the bottom 2 1/4" retaining bolts to help spread the clamping. Then run a bead of silicone around the T/C from one side of the cover to the other up to the center line of the crank nose. All to address oil leakage around this area. Often, the core engines I get have slightly bent/warped plates and all this is in an effort to reduce any chance of leakage from a plate that isn't quite as flat as it left the factory 40+ years ago.

HTH,
Mike
 
Any tips on how to actually remove and replace the seal itself?

Is it driven out or cut out?

Is the new seal glued in in some way? How is it actually attached?

thanks
Fred
 
With the timing cover off and on a flat surface, I use a large flat blade screw driver to drive the seal rearward and out of the retaining ring formed in the timing cover. Sometimes takes a couple of hits with the hammer on the end of the old screw driver handle.

Most of the time, the seal fit into the cover is tight enough that no adhesive is required. Every now and then I find a timing cover that needs some help and I'll use some general automotive adhesive.

To install, I turn the timing cover over and position the seal in the retaining ring with the flat side towards the outside of the cover. I can usually cock the seal and get the initial insertion by hand. Then follow up with a 12oz. ball pien hammer and make sure the seal is installed all the way to the lip of the formed ring. Also use a short piece of clean 2x4 to hammer against sometimes.

HTH, Mike
 
Thanks Mike,
I find it's always best to ask about things you haven't done before, even if it seems simple. That attitude has saved me a lot of trouble.

BTW, my timing cover has a dent in it just above the seal, which cants the seal about 10 degrees relative to the true perpendicular of the crankshaft. That angle is probably why it leaked, because the seal itself looks fine visually, and fits snugly to the balancer as long as it is slipped over it at an angle.

I guess I'll try to hammer it out to get it straight. Then maybe just leave the old seal in.

Are the replacement seals that come as part of the gasket sets from the big parts houses good quality?

Fred
 
I've had to "adjust" many timing covers in the past. Most of the core engines I've accumulated have come from a salvage yard and events that got the car into the yard in the first place were front end hits. A piece of 2x4 and a 12oz ball pein work wonders.

Seals are usually equivalent across the spectrum of gasket sets. The seals mostly come from the same places and/or use similar construction and materials.

As long as the seal dust lip and seal surface is soft, pliable and not worn/flat spotted, it should still work fine.

Mike
 
The timing cover adjusted nicely with the hammer and 2x4 method.
The old seal was also rock hard and had to be scraped and cajoled out of it's place.
New seal is nice and pliable. Pressed it into the back of the timing cover with no need for any adhesive or sealer, as stated.
Then I put it back on, keeping the bolts loose until the balancer was torqued home. Then snugged put the timing cover bolts.

Now it runs great with nary a drop of oil front or back.

Hoorah!

Fred
 
Congrats! The way it should be...
Rut
 
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