help with 81 cj-7 - engine, vibration, steering wander/over steer

The valve covers on those things always leak like a bitch. Take it off, clean it up and make sure the gasket service is clean. I used quite a lot of RTV and properly torqued it down afterwards to seal it up. I didn't even use a gasket and it lasted me two years until I yanked the motor.

As far as the leak at the back of the engine and the one that looks like it is coming from the transmission. That would be your rear main seal which isn't a hard job but it is time consuming and messy. You have to have patience when doing it but it can be done.

Sounds like mounts somewhere are toast. Check the engine mounts and also check the transmission mount. I had the same problem on my 4.2L/Auto/NP231 combination. It turned out that the tranny mount ripped itself out because of a dying engine mount.

Have you replaced the tie rod ends and your steering shaft at all? When I first got my 1989 YJ it has so much play in the steering shaft and the tie rods. I replaced those which helped but just like you I also had play in the steering box. I had a local shop do a rebuild on it which cost me $150CAN and it was good to go. The Jeep steering perfect after that.

Hope it helps!

Valve cover gasket, rear main seal, loose tranny mounts, and loose steering box mounts. That's what I would be looking at... been there, done all that. Some vibration could also be caused by a bad clutch/pressure plate and flywheel... they could be "wash-boarded" from heat.

Ok.....

Well the photo shows a leaky valve cover.

These are difficult to seal up. If you take it off to change the gasket you must have it perfectly clean or it will leak. Even one fingerprint is enough to leak.

I use acetone or coleman camp fuel to clean it, then use a thin coat of RTV silicon on both sides with a cork gasket between. Over 2 years and still no leaks.

This leaky valve cover is also causing the drip near the rear main seal in 99% of the cases so fix that first.

It also could be the source of the oil on the bottom of the tranny. Oil will spread back from wind.

Second you have a broken tranny mount and maybe a broke engine mount too.

These are easy to change and should be fixed ASAP before the engine up and falls out on you... Been there, done that, it wasn't fun...

Because the engine isn't sitting straight, you likely have damaged some u-joints in the front driveshaft that will cause it to shudder in 4x4, but until you fix the mounts it is a guess.

Why do you have shims on your axles????

Tell me about that so I can have a proper guess to your steering issues.

Mike

brad smith wrote:

Here are some more pictures (better than 1,000 words!)

Should I go with the urethane or rubber engine and tranny mounts? I don't mind going with rubber because I know that it would cushion the engine/tranny more and if I have to replace them in

I just realized that the shim on top of the spring pack is causing me to have less caster, rotating my axle toward the front and causing less stable steering. I knew this newsgroup would help me out! :)

I have tried to capture what the oil I was talking about on the bottom of the bellhousing/transmission looks like. you can see where the inspection plate is pulled away about 3/16" to 1/4". I know I need to get a new clutch (look at the clutch fork boot- it is totally destroyed.) My question is can I replace the clutch without pulling the engine - it looks like I could drop the tranny/transfer case and get to it that way...

Anyway, thanks for the help so far. I am going to replace my valve cover with an aluminum model when it warms up this spring.

Brad.

#3 Steering

Have a buddy crank the wheel back and forth while you have a good look at the brace that connects the steering box to the frame. They are a common place of failure, they crack around the bolt holes of the brace. And while he is cranking left and right look for any other loose parts. Anything that is loose will just add up to the big picture, and anything you fix will subtract from the loose feeling.

Man you really need to trim the size down on those photos.

I have a Sony digital Mavica and I can put 15 high quality photos on one

Question!

Does your engine burn oil?

-----------------

Your mounts are sponge rubber looking, fractured bad and need to be changed. The tranny mount is broken because all the oil leaking down the back of the engine from the valve cover and then blowing back has caused the rubber to disintegrate. Just an educated guess, but bet I am right.

I would recommend rubber mounts and I would recommend you go to the dealer for them. Ya I know, the '$tealer', but the stock mounts have lasted this long, so.... I have torn 3 sets of aftermarket engine mounts apart in 3 years and my local Jeep shop also recommended OEM mounts for me.

Do you have oversized shackles on the springs? CJ ones are 3" I think and YJ ones are 4" I think. Long shackles make a need for axle shims. No way a 2.5" spring lift needs shims. That is what I have and I have the YJ shackles that give an extra 1/2" lift.

Oh, CJ's have rock hard springs. I have new OEM springs arched to 2.5" with the top leaf replaced with a tempered 'keeper' spring and they are rock hard. The only soft bit I get is from the right air pressure in my tires....

Steering....

Wheel bearings are a sneaky thing in the front. They need to be repacked and retorqued on a regular basis. When water crossing or mud running, I do mine twice a season.

If the wheel bearings are the slightest loose, the steering will wander. To test them, jack it up and grab the tire at the top and bottom and pull in and out. If you have play, the bearings need servicing. They normally should be repacked with every brake pad change if in normal duty.

A bad ball joint also can cause wander. To test, with the vehicle on the ground, grab the top of the tire and pull it in and out hard! Get the Jeep really rocking side to side and then feel for clunks or shuffles.

Why do you think you need a new clutch?

The boot is real rubber and the oil leaking down from the valve cover turns it to jelly. Mine was in shreds when I did my frame up rebuild.

Where does the clutch engage on the pedal?

The pedal should have about 3/4" of free, flop around play at the top, then the clutch should grab about halfway along.

If yours sounds like that it is working perfect. If it grabs at the very top and you have the top free play, it is worn out.

If no top free play, it needs adjusting. The 'book' adjustment is for

With blown tranny and soft engine mounts, the clutch will act very strange and sometimes grab up top, down low, grind, shudder bad on take off, bitch and generally not act nice.

If you need a clutch, they are easy to do from the bottom if you don't mind working under. I am tall and prefer to work from the top so I like to pull the engine. Have a sweet big tree over my driveway for an engine hoist anchor too. :-)

I just helped a guy do his in my driveway at -25C temps a couple weeks ago. There is a post/thread about it here.

He is short and prefers working on his back so he dropped the skid plate and tranny from the bottom.

I do not think you need to worry about that from your symptoms. Unless there is more you haven't said?

Oh, the aluminum valve covers leak just as bad if not put on perfectly clean eh!

My plastic one only has the two nuts up top holding it on! The engine head isn't drilled and tapped for the side bolts!!!!

Still with only the two nuts and the plastic cover, no leaks because I made it perfectly clean before setting the RTV in and let it cure!!!

The RTV also takes 24 hours to 'cure' so you don't add oil or go near it for the 24 hours.

Mike

brad smith wrote:

yes, I usually have to put about a quart in every 1500 miles, from what I have seen.

(sorry about the picture size, I am spoiled with my high speed internet connection :)

brad.

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Mike

brad smith wrote: