Timing Chain Covers

[porsche boy]

Hi There, my 1995 993 with 82k on the clock has leaking/weeping timing chain covers. No surprise. Can you buy billet timing chain covers? I cannot find any on the web. If none available can you help on a way to cease the leaking? Is it a simple buy new gaskets and grommets? If yes, how long will they last. Need info please as I am sure there are many helpers out there.

I replaced my valve covers to billet and not a drop has fallen.

[jhg41977]

I have not seen a billet cover for the chain boxes. You'll need to replace the individual bolt gaskets and the main cover gasket. You may have a few studs come out when you do this so be prepared with some lock tite.

[earossi]

Your existing covers should be fine if sealed properly and torqued correctly. To do this remove the covers and check with a straight edge to determine that they are flat across the gasket surfaces. If not, you can lay out some fine wet/dry sandpaper on a flat surface and sand the covers to flat. You can start out with a coarse paper and then move to finer papers. When done, the covers should be flat and the sealing surfaces need to be smooth without an scratches or voids.

Use the paper gaskets specified for the sealing of the covers; however, spread a very thin layer of Loctite 574 on both sides of each gasket before installing.

Lastly, cross torque the covers in place and do NOT over torque the covers. Over torquing them will deform them. IIRC, torque values are very low......down around 8 ft-lbs. So, don't over tighten them.

Done as above, you can expect the gaskets to not leak for the duration of the engine between rebuilds.

[geshleman]

Also had leaking timing chain covers on my 1994 964. Decided to tackle it and it wasn't too bad getting at the one on the driver side--the main culprit. Looks like passenger side will be much more difficult though, need to get the AC bracket off.

Just removed the driver side cover and here are some picks. Does this look normal with all the gray muck on the surface of the housing and gasket? I assume this is some sort of sealant but seems to have also gotten on some of the internals too.

Does not look to be easy getting this stuff off, is it OK to use something like a very fine cross-buff to take it off?

Also, should I also use a sealant with the new gasket. I've used Permatex Right Stuff on other cars but is there something better for these covers?

[hepkat63]

looks like paint to me? Either way, it would have to come off. I'd just use a fine sandpaper, looks like it would come off pretty easily.

[hepkat63]

did you take any other photos of the steps involved to get to your timing cover (s) please?

[hepkat63]

knew i saw it somewhere else - see here: http://forums.pelicanparts.com/911-engine-rebuilding-forum/218576-964-3-6-engine-top-end-2.html

[earossi]

Originally Posted by geshleman

Also had leaking timing chain covers on my 1994 964. Decided to tackle it and it wasn't too bad getting at the one on the driver side--the main culprit. Looks like passenger side will be much more difficult though, need to get the AC bracket off.

Just removed the driver side cover and here are some picks. Does this look normal with all the gray muck on the surface of the housing and gasket? I assume this is some sort of sealant but seems to have also gotten on some of the internals too.

Does not look to be easy getting this stuff off, is it OK to use something like a very fine cross-buff to take it off?

Also, should I also use a sealant with the new gasket. I've used Permatex Right Stuff on other cars but is there something better for these covers?

Grey stuff appears to be a sealant like some sort of Permatex. I would clean all of that off both surfaces (chain covers and chain housings). Also, remove any debris from the chain housings left from any of the gaskets.

Though Ceril II can be used for the chain housing covers, it is better used around O-rings. For the chain housing covers, I used a VERY thin layer of Loctite 574 spread onto both sides of the gasket. Spread the 574 with your fingers. You don't want a layer of the stuff.....just enough to moisten both sides of the gasket thoroughly. Just be certain that all the parts are absolutely clean. My engine does not leak or weep at any of these gaskets cover plates.

[geshleman]

I did not take pictures but generally followed an earlier post by perelet (sorry don't know how to give you the link). It was thread #644446.

It was pretty straightforward:
1. Drop exhaust system (I left the heat exchangers in place). Used deep creep on the nuts and they all came apart easily. O2 sensor on driver side needed to come out. Location of fasteners becomes very apparent.
2. Remove rear engine tin. About 8 10mm bolts removed from above. The 11mm nuts that you see from underneath are welded to the sheet metal-don't try to remove. Had to remove the air duct on the left side of the engine to get easy access to a few of the bolts. Some maneuvering required to wiggle it out.
3. Driver side timing cover is now easily accessible. May need to loosen distributor slightly to get better access to a few nuts, but I didn't remove it.

Haven't gone after the passenger side yet, but looks like the following steps:
4. Support engine and remove rear engine support bracket from rear mounts.
5. Remove AC compressor (hoses stay connected), remove drive belts.
6. Remove drive pulley (may need special tool 0072192851). Perelet removed the rear bumper and had easy access, I'm hoping not to have to do this.
7. Remove AC bracket
8. Should give me access to the passenger side timing cover

With everything apart I'm planning on replacing the timing cover gaskets (2), rubber seals for the nuts (18), chain tensioner gaskets (2) and O-rings (6 total, 2 different parts) for the oil bridge that feeds the housing. Will probably also do my valve covers, valve adjustment and plugs while I'm at it, but will have to drop the heat exchangers for this.

So far it's been much easier than I anticipated.

[hepkat63]

Originally Posted by geshleman

I did not take pictures but generally followed an earlier post by perelet (sorry don't know how to give you the link). It was thread #644446.

It was pretty straightforward:
1. Drop exhaust system (I left the heat exchangers in place). Used deep creep on the nuts and they all came apart easily. O2 sensor on driver side needed to come out. Location of fasteners becomes very apparent.
2. Remove rear engine tin. About 8 10mm bolts removed from above. The 11mm nuts that you see from underneath are welded to the sheet metal-don't try to remove. Had to remove the air duct on the left side of the engine to get easy access to a few of the bolts. Some maneuvering required to wiggle it out.
3. Driver side timing cover is now easily accessible. May need to loosen distributor slightly to get better access to a few nuts, but I didn't remove it.

Haven't gone after the passenger side yet, but looks like the following steps:
4. Support engine and remove rear engine support bracket from rear mounts.
5. Remove AC compressor (hoses stay connected), remove drive belts.
6. Remove drive pulley (may need special tool 0072192851). Perelet removed the rear bumper and had easy access, I'm hoping not to have to do this.
7. Remove AC bracket
8. Should give me access to the passenger side timing cover

With everything apart I'm planning on replacing the timing cover gaskets (2), rubber seals for the nuts (18), chain tensioner gaskets (2) and O-rings (6 total, 2 different parts) for the oil bridge that feeds the housing. Will probably also do my valve covers, valve adjustment and plugs while I'm at it, but will have to drop the heat exchangers for this.

So far it's been much easier than I anticipated.

Thanks for that - appreciated.