change timing cover gasket

[fgross2006]

AGAIN!!!

I did it last winter and still had a leak in the upper driver side, then I replaced it a few weeks ago, just started the car today for the first time, immediate leak from the rubber seal between the timing cover and the oil pan.

Where did I go wrong on this? Now I have to break it all down again and re do it once again. When the engine idles there is a steady drip from the rim of the oil pan just below the timing cover.

Any advise? Should I use more RTV on the rubber seal? I didn't think it needed much so I just smeared a little with my finger along the edge.

[83gtstang]

I've done this few times or so myself. Tighten all you bolts over again. The heat causes the metal to expand causing the gaskets to compress, then the metal shrinks, leaving the gasket materials loose and seal is broken. After I complete a water pump change or front cover replacement for timing chain etc...I always make sure I go over every bolt at least 3 to 6 times over a few hours. You will be amazed how loose the bolts become after initial tightening. It has always worked for me, before I learned to retorque, going in afterwards and tighten things up again. You may need to move or remove some items to be able to get to some bolts. Hope this works for you. Also works on hose clamps, just don't over squeeze the rubber, use common sense. Good luck.

PS...if you have retorqued and still leaks, disregard.

[fgross2006]

I've done this few times or so myself. Tighten all you bolts over again. The heat causes the metal to expand causing the gaskets to compress, then the metal shrinks, leaving the gasket materials loose and seal is broken. After I complete a water pump change or front cover replacement for timing chain etc...I always make sure I go over every bolt at least 3 to 6 times over a few hours. You will be amazed how loose the bolts become after initial tightening. It has always worked for me, before I learned to retorque, going in afterwards and tighten things up again. You may need to move or remove some items to be able to get to some bolts. Hope this works for you. Also works on hose clamps, just don't over squeeze the rubber, use common sense. Good luck.

PS...if you have retorqued and still leaks, disregard.

So you think I may be able to stop the leak without pulling everything off again by re torqueing?

This leak is from the rubber seal that goes around the bottom of the timing cover. theres no bolts to tighten that. I can re tighten the 4 oil pan bolts in front but im always afraid the cork gasket will break if I do that.

One other thing.

I recall when I was placing the timing cover onto the block there was two bushings in the lower two holes that seemed to be there to line up the timing cover. No matter how I tried I could not get the locating bushings to line up into the block and the timing cover together. I had to let them slide into the timing cover. it just want happening. What's the trick to getting those 2 bushings to align? Could this be part of the problem?

[83gtstang]

Ok so it's the front main seal or the actual oil pan to timing cover gasket. I know the alignment tabs you speak of. I always pre-assemble the gaskets to the timing cover. You sometimes need to do some trimming to the gasket to get it to sit properly. I always use a bead if sealant where the rubber and cork meet. You may get away with a retorque. If not you will have to pull the pulley, balancer etc.

[83gtstang]

Oh by pre-assemble, I mean I take the timing over, get RTV, get the gaskets and put the gaskets on the cover, along with the water pump, and put it all together, then let it dry completely together. To include the lower gasket that will eventually go into the oil pan and the front main seals. This prevents gasket slip, which may have happened if you tried to do everything with wet RTV.

[fgross2006]

Ok so it's the front main seal or the actual oil pan to timing cover gasket. I know the alignment tabs you speak of. I always pre-assemble the gaskets to the timing cover. You sometimes need to do some trimming to the gasket to get it to sit properly. I always use a bead if sealant where the rubber and cork meet. You may get away with a retorque. If not you will have to pull the pulley, balancer etc.

The leak I have now is the rubber seal in between the timing cover and the oil pan. Not the front main seal for the driveshaft/harmonic balancer.

Attachment 89195

Hard to see the leak in this pic, but that's where sits leaking


I wasn't refuring to alignment tabs on the gasket, I was talking about two small bushings that when seated into the block protrude about a 1/2 inch and are supposed to also slide into two same sized holes in the timing cover. I believe this lines up the timing cover.

[83gtstang]

The alignment dowels? I had the same issue, but was able to get it to work. You can loosen the oil pan some to allow a small gap, this gap gives you just enough room to get the front cover on. Then lift the pan up by tightening the oil pan bolts then the four bolts that go through the front cover. I think I used a rubber mallet for my Explorer cover while pushing down. It was really tough. I suggest if you can, drop the oil pan a little and see what happens.

[TheWizard]

Did you thoroughly clean all the matting surfaces? And how long did you let it cure?

[fgross2006]

Did you thoroughly clean all the matting surfaces? And how long did you let it cure?

I cleaned it spotless, and I let it sit for 2 days before I put oil in the crankcase and it sat for another week before I started it.

[fgross2006]

My mechanic says we can drop the oil pan and replace the entire oil pan gasket with a one piece steel core felpro. It may still be the front main seal too. Here's a vid, what do you guys think is the source of the drip?

[grabbergreen84]

I'd guess the front main, after seeing that drip from behind the balancer at the end of the vid. If you don't see any evidence of oil above the balancer, then go ahead and pull it back off, and see what it looks like under there.

If the leak is coming straight down, then it's the main seal, but I suppose it could be running down to the center, from the block/timing cover/oil pan joint(s).

Engine sounds pretty smooth.

[gt pony]

That's the front crankshaft seal leaking. Pull the balancer and pop the seal out and replace it with a new one.

Pack the backside of the new seal with Vaseline so the circular spring will stay in place when you hammer the new one in. Then take a scotch brite pad and clean the surface on the balancer where the seal will ride. If it has a deep groove in it where the old seal was riding you can get a sleeve to slip over the balancer hub from the parts store, in fact they may ask you if you want the seal by itself or one with a sleeve.

[83gtstang]

Looks like the lower seal slipped as well. I agree with the front main seals causing a groove in the balancer snout. I had to put a sleeve on mine, it was grooved bad. Believe it or not, the rubber on the front seal can really groove the metal. I bought a front gasket set from Pep boy's, it came with the repair sleeve and all gaskets necessary for timing over and water pump change, to include front seal and repair sleeve.

[83gtstang]

Definitely front seal leaking.

[fgross2006]

That's the front crankshaft seal leaking. Pull the balancer and pop the seal out and replace it with a new one.

Pack the backside of the new seal with Vaseline so the circular spring will stay in place when you hammer the new one in. Then take a scotch brite pad and clean the surface on the balancer where the seal will ride. If it has a deep groove in it where the old seal was riding you can get a sleeve to slip over the balancer hub from the parts store, in fact they may ask you if you want the seal by itself or one with a sleeve.

when I changed the timing cover gasket, timing cover and timing chain last winter I put a new front main seal in. When the timing cover gasket failed and had to be done again last week, I didn't think the front main seal needed to be replaced again as it was just changed 6 months ago. Also, the harmonic balancer was replaced last summer. All the videos I looked at said that a puller would be needed to pull the balancer. Both last winter and last week the balancer came right out with a slight pull with both hands. no puller was needed at all and for a balancer that's about 15 months in the car I don't know if that's good or bad.

This time I did see a very slight line around the snout but not deep enough to catch with a finger nail so I polished it with steel wool and didn't use the repair cap that came with the timing cover gasket.

Im thinking now the best way to solve this once and for all is to change the front main seal, put the repair cap on the balancer and replace the oil pan gasket with a steel core rubber one piece gasket.

Since my mechanic is already working on the dual exhaust conversion and he will be loosening the motor mounts, the tranny mount and removing the cross member, now would be the best time to take care of the oil pan gasket. Pulling the balancer again is minimal extra work.

Thanks for the help everyone

[83gtstang]

I wouldn't think the balancer pulling out by hand is a good thing. I have never had one do that before.

[gt pony]

when I changed the timing cover gasket, timing cover and timing chain last winter I put a new front main seal in. When the timing cover gasket failed and had to be done again last week, I didn't think the front main seal needed to be replaced again as it was just changed 6 months ago. Also, the harmonic balancer was replaced last summer. All the videos I looked at said that a puller would be needed to pull the balancer. Both last winter and last week the balancer came right out with a slight pull with both hands. no puller was needed at all and for a balancer that's about 15 months in the car I don't know if that's good or bad.

This time I did see a very slight line around the snout but not deep enough to catch with a finger nail so I polished it with steel wool and didn't use the repair cap that came with the timing cover gasket.

Im thinking now the best way to solve this once and for all is to change the front main seal, put the repair cap on the balancer and replace the oil pan gasket with a steel core rubber one piece gasket.

Since my mechanic is already working on the dual exhaust conversion and he will be loosening the motor mounts, the tranny mount and removing the cross member, now would be the best time to take care of the oil pan gasket. Pulling the balancer again is minimal extra work.

Thanks for the help everyone

When you replaced the front seal 6 months ago did you pack the backside with Vaseline to keep the seal spring intact? If not, there's a good chance that the spring popped out and there's no tension on the seal which would cause it to leak. I would try the seal replacement first, it's easy to do as I'm sure you already know. The balancer being easy to remove may be a machining error, but I don't think it's a serious issue as a lot of engines have slip-fit balancers right from the factory.

[83gtstang]

Reason I say that the balancer slipping off easily is I once had one spin on the crankshaft, breaking the key way and heat welding itself to the snout ruining the whole crank. I guess it was a quick stab of the pedal while racing around that did it.

[fgross2006]

My mechanic says we can drop the oil pan and replace the entire oil pan gasket with a one piece steel core felpro. It may still be the front main seal too. Here's a vid, what do you guys think is the source of the drip?

You can clearly see in this vid that I have a bad leak which appears to come from the timing cover front main seal.

My car was at my mechanic for the past week. He was upgrading to dual exhaust. I asked them to de grease and run it to determine the cause of the leak. They informed me that its no longer leaking. I got under the car myself and watched it run for 10 minutes and the front of the engine is still bone dry.

How is that possible?

Its no longer leaking oil but is now leaking anti freeze from the bottom of the radiator. Now I have to pull it yet again and take it to a radiator shop to have it soldered.

has anyone seen an oil leak like I have in this video just clear itself up?

[83gtstang]

It's possible that it wore the rubber down enough to fix small imperfections, possibly a folded rubber seal or debris. Whatever it was if it's fixed, then it is what it is. Ave you 're-tightened all the hose clamps at the hoses to be sure it's not the radiator? I would tighten them up and power washer it, drive it around and see if you see any coolant.

[fgross2006]

It's possible that it wore the rubber down enough to fix small imperfections, possibly a folded rubber seal or debris. Whatever it was if it's fixed, then it is what it is. Ave you 're-tightened all the hose clamps at the hoses to be sure it's not the radiator? I would tighten them up and power washer it, drive it around and see if you see any coolant.

All the hoses are dry and the bottom of the radiator has a constant drip. Im gonna pull the shroud to see if I can get a better view.