Rhyno

So I have a pretty serious problem.

I have 1999 Cherokee Sport 4.0.
Last week I swapped out my seized AC compressor for a bypass pulley. After the swap the Jeep ran great, quieter than ever. Well last night the belt started to squeak a bit. So today I loosened the belt, made sure it was on properly and tightened it back up. As I left my neighborhood I heard a a very loud smacking noise and pulled over. It appeared that the belt had slipped off. Thankfully I had tools with me and i loosened the tensioner and put the belt back on but I could tell right away something was wrong.

The belt didn't fit the pulleys properly anymore and after a closer look I found that the radiator fan would tap the crank pulley if I spun it. The crank pulley appears to be protruding half an inch further than it should be.

Am I boned here? I really doubt this is cheaply fixable.

5-90

Your harmonic damper is shot. Replace it.

Don't get Dorman aftermarket - reports from the field say they're not machined quite right, and don't fit over the snout (the last few I've installed have been Pioneer-branded, and have been fine.)

OEMR is also a possible - the Pioneers I've bought have been around $50, OEMR would probably be slightly higher.

Replace the front main seal while you're in there.

If you have an oil slinger behind the HD, you'll probably need to remove it.

And, you'll need a special Harmonic Damper Puller (probably $20-25 at the local, some places will hire them out) and a special installer (I use a 1/2"-20 hex head capscrew and a stack of greased washers) to press it back on.

Cheaply? If you buy everything, you're probably in for a hundred bucks (tools and parts,) and you're still ahead of what a shop would charge you. It can be done in an afternoon (and done more thoroughly by you - most shops won't do the seal - even though they're already there!)

Rhyno

While I'm not afraid to do this myself, is there a good guide on this somewhere in case I get lost? I'm still learning and consider myself a novice. The repairs I have accomplished are a new front wheel bearing, new alternator and the mentioned AC repair.

5-90

Sounds like you're off to a good start, then.

I'm not sure if there are any writeups on here (I haven't looked,) but I think I've covered the subject once or twice on NAXJA (same handle there,) and I'm sure it's been covered a few times there by someone other than me as well.

And, if you can get at least a Chilton's manual, it will tell you what you need to know.

Howler_GT

I JUST replaced my harmonic balancer yesterday on our 91 Laredo.

Here are some tips I will pass along:

-Before any work. Run to your local self-serve car wash and blast everything underneath with engine degreaser or tire cleaner. Then High pressure soap, then a quick rinse. IF not mobile, give it a good cleaning with some engine degreaser in driveway. The cleaner the better.

-Do not remove belt first. With the belt tensioned the way it should be, place a large ratchet with (IIRC) 3/4" socket. Do not try to "just turn it" the motor will just turn. Rather hit the very end with the palm of your hand several times, the sudden hits will loosen the monting bolt.

-Remover: Use the shortest bolts possible. Also, make sure there is something on the end of the crankshaft that will prevent the remover's main screw from protruding into the crankshaft threads. IF you run into the crank spinning problem, just use the technique for removal of mounting bolt. Quick sudden hits.

-Replacement part: I found that Rock Auto has the best price on replacement harmonic balancers. Mine came with new woodruff keys. Didn't need them, but good to have IF I would have needed them.
PLUS: Good idea to replace the front crankshaft seal while you're there.

-Seal: Use of a large socket is a plus. One that just fits the outer diameter of the seal. Take your time and make sure it goes in straight.

-Lube: Before installing the balancer, it is a good idea to oil all the parts.
Balancer- Inside diameter and outside diameter.
Seal- Anywhere that comes into contact with the balancer.
I use the same motor oil I have in the crankcase (Same brand and viscosity...NOT the ACTUAL oil...that would be wrong) I have some in an oil can so I can just squirt it all over the place.

-Patience: Take your time. You will be constantly wiping your hands.

-Finishing up: The balancer is in far enough when it is flush with the end of the crankshaft. At least on the 4.0L as for the 2.5/2.8 I am not completely sure. Someone that has done one of them may be able to shed some light onto that answer.

HTH

Rhyno

Due to work I havn't been able to tackle this job until today and I'm stuck.
Got the balancer off but I just can not get the seal out. I've tried everything I can think of and it's just stuck in there. Suggestions?

JeepingDan

its easy A flat screwdiver and a hammer mangle the little bastard up until it comes out just don't damage the timing cover.

98 JeepJeep

any room to fit a seal puller in there?

Rhyno

I tried and tried and it just would not budge. I finally gave up and put the new balancer on. Since the tool rental was free i'll just give it another whirl in a month or so when i have a week off.

Thanks for the help and support guys, I was getting really frustrated with the jeep but the feeling yo get after fixing something is fantastic.

Next up, water pump, thermostat and radiator hoses.

bikegaffer

where did you get your bypass pully?
i have not been able to find anyone with one for a 1999 cherokee 4.0
did you use one for a 1998?

yorkite

Curious...do you have to remove the radiator like the chilton's says in order to replace damper and seal?? Just hoping maybe certain tools would fit without removing.

freegdr

no, need very small puller now the seal is going to be fun though

tuxfan212

I just did this in about 2 hours on my cherokee. Remove the mech fan, electric fan, water pump pulley, and belt. I used a regular old wheel puller on the harmonic balncer and if needed you may be able to remove the bumper and do it through the hole in the support. Once the balancer is removed remove the timing cover. Buy the timing chan cover gasket and front seal and punch the old one out with a screw driver. I used a spool of wire to tap the new seal in and re-assembled the entire thing.

yorkite

that's real good news to me! thanks to all!

XJ Rat

My son just changed his in the dorm parking lot at school (89) and a friend just changed his in a convenience store parking lot (98).

No, you do not have to remove the radiator as there is plenty of room down there. Autozone rents the puller 'free'. Just look at it real close to make sure the threads are not buggered up on the shaft. Many people make an error and do not thread the shaft into the harmonic balancer far enough. Resulting in the threads being pulled off the shaft.

Not a difficult job, just takes some time.