A case of "while I'm at it" (timing case cover)

I am in the middle of changing the water pump on my ‘89, 280K miles, 4.0 engine. Right now, everything is apart, cleaned and ready for assembly. I have new H2O pump, t-stat, lower rad hose, and idler pulley ready to go in. I am taking my time and doing a little at a time. When I pulled the water pump yesterday, there was *a lot* of crud and goop around the timing case cover. I said “Aha”; I may have found the source of the oil leak that has nagged me for a long time.

After many cycles of degreasing, I can now see the bolts. I was going to tighten the bolts, but like any noob should, I read the FSM first, to see if there is gasket under there I can change. Well, much to my disappointment, apparently I can’t just pull the cover and change the gasket. There is a tool, called “Timing Case cover Alignment and Seal Installation Tool J22248” which, the best I understand, is used for installing/replacing/aligning “crankshaft oil seal” and “oil slinger”. I have never dealt with changing these, and they sound way over my head, not to mention I don‘t have the tool mentioned in the FSM. BTW, there is no gasket in there and the FSM talks about using RTV.

Since there wasn’t much goop around the damper pulley, just where the case cover met the block, I am assuming/hoping the front crankshaft seal is “OK“.

My question is if it’s worth going through pulling the A/C compressor, and everything else I need to, so I can get to about a dozen bolts for the timing cover, and just tightening them a little in the hopes of stopping the leak? Sorry for the long post, I just wanted to give the complete picture.

TIA .. Maz

Well...
If it's any colsolation, I've never needed that little "special tool" for the front mains I've done on the 242 (about three to date.) You do, however, require a "Harmonic Damper Puller," which can be had at any well-stocked parts house. You might also want a "Harmonic Damper Installer" - you can probably get that at the same time - or you can use a 1/2"-20 bolt and a stack of washers to get the same result.

RULE - NEVER use a hammer on a harmonic damper!

If you're getting all crapped up, tightening the bolts probably won't work. It's a paper gasket, and when those fail, they're failed.

You should be able to get the gasket and front main seal as a kit - TCS-something or other (I don't have the part number handy right now.)

If you watch what you're doing while you pull the bracket, you'll spot the bolt that gets interfered with. As I recall, grinding one of the sides down about 3/16" will allow you to remove the bolt without having to tear down the front of the engine next time - and that saves you trouble. Grinding only one side does the job, and you can still use a wrench or socket on it.

So, there IS a gasket in there - or available to go in there - and you should handle the seal while you're in there. Clean thoroly, and reassemble. Be careful to NOT shear off the woodruff key that indexes the damper - all you have to do there is make sure you're lined up before you start to press.

You'll have an easier time with the damper going on if you lube the snout of the thing with some engine assembly lube or similar, and work slowly. Also grease at least three of the washers in the stack - that makes it easier for everything to "slip" and not hang up.

Most OEM seals can't recover from retorquing the bolts, unless you catch them immediately.

5-90

A technique I´ve used to align covers on various gear boxes, is to drill a small hole through the cover and into the block (or housing), the diameter of a finishing nail and use the nail to align the cover while tightening. Doesn´t have to be much of a hole or very deep, just has to be almost exactly the diameter of the nail, rod or whatever you use.

You don't need that special tool if all you're doing is replacing the front seal, because the seal centers in the housing and the housing remains undisturbed. When you remove and reinstall the housing, it is critical to get the hole in the housing perfectly centered on the snout of the crankshaft, and that's where that tool becomes necessary.

You probably don't need to remove the timing cover to stop the oil leak. The front seal itself is replaced from the exterior. Remove the harmonic damper as 5-90 described, yank the seal, press in a new one, and reinstall the damper. Be sure to oil up the lips of the seal so it doesn't burn up as soon as you start the engine.

Thank you all for the very informative suggestions.

On the nail technique, how do you patch it afterwards, drive a very short screw with some silicone?

From the sound of, I'll have to take off most everything on the front, including the radiator.

I'll wait on all these until I do a compression check to see about the health of the 280K mile 4.0. It may not be worth all the trouble if she is on her last leg; especially that I am sure as I tear up more into it, I'll run into more "while I am at it" syndrome.

-Maz

I used the nail or pin technique with a silicon type seal, drilled through the middle of where the seal is or the gasket would be if used (not very far from a bolt hole). The 2 holes I drilled were about 3 mm (around 1/8 or 3/32"), not much chance of it leaking. I wouldn´t drill into the housing or the block very far. If you drill two holes before removing the cover, you can get the cover back on, in almost exactly the same position. If you use a gasket, a little gasket glue (around the bolt holes), really helps keep things in place during reassembly.
I´ve also scribed a line around the outside of the cover, where ever the cover was smaller than the housing/or block. But the scribed line is hard to see if you use silicon and hard to line up exactly.
In another post, a guy mentioned installing the damper into the new seal, just far enough to center it, then installing as many of the mounting bolts as possible. Don´t really know if you´d have to pull the damper back off to reach some of the bolts or not, seems likely though.

8Mud said:

I used the nail or pin technique with a silicon type seal, drilled through the middle of where the seal is or the gasket would be if used (not very far from a bolt hole). The 2 holes I drilled were about 3 mm (around 1/8 or 3/32"), not much chance of it leaking. I wouldn´t drill into the housing or the block very far. If you drill two holes before removing the cover, you can get the cover back on, in almost exactly the same position.

Click to expand...

Very clever, I really like this technique. Thanks for sharing.

Cheers ... Maz

J8129097 Gasket & seal kit Jeep part #,just did the 87 and used this,crank seal,cover gasket and oil pan front gasket.less than $10 IIRC
Wayne