Rubber components

[asymptonic]

Just a quick double check. Recently gunned my 98 (233k miles) merging and had a horrible metal noise that required a tow later. In trying to replace a chewed up belt while waiting for the tow, noticed the harmonic balancer had drifted into the fan belt. Fortunately only that. But over the last 5 or so years I've been replacing parts on the Jeep that are old and rubber and aging out. I'm pretty sure there's nothing left that's mission critical. I still need to do front bump stops, but I've done sway bars, control arms, motor and transmission mounts, rear bump stops, leaf springs a while back, and now harmonic balancer. Just want to ask if there's anything else I should check. The little stuff I don't sweat but this was annoying.

 

[Anak]

Rubber is indeed the issue.

If you have not yet done that harmonic balancer job I would expand the scope to include a new timing chain and a new chain snubber. That snubber is another piece of rubber which will by now be as hard as plastic. And of course, while doing that job you will want to replace the front crank seal.

You have not mentioned which seals you have replaced over the years. Not only are seals important for keeping the good stuff in, but also for keeping the bad stuff out. Axle seals are where that is most likely to be an issue, especially if you ever do any water crossings or boat launches. The cooling effect of the water can create a vacuum, sucking in the water and whatever sediment is in it.

Other seals which don't get much attention are the body seals. Leaks around the windshield and doors lead to rusted out floor pans. Leaking window wipers (door windows) lead to doors rusting out from the inside (I haven't seen this to any great extent on XJs, but I have seen a lot of it in older GM vehicles--give it time and any vehicle can have issues).

Also take a look at the rubber lines going to your axles. If you have not replaced your brake hoses for the sake of a lift odds are those are due. And then the axle vent lines never seem to get any love, and those share the same issues as the rest of the axle seals.

Those are what come to mind off the top of my head.

 

[DirtySouthXJ]

Rubber is always a problem and an even bigger problem for vehicles that aren't well supported by the aftermarket. Hopefully the XJ's are popular enough that repro rubber will be made/availible in the future. Imagine owning a vehicle with trashed rubber and no replacement? Seals etc. the vehicle would never be complete and unusable in poor weather, or even washing. This is something (along with many other parts) that is constantly on my mind when looking at vehicles. Something like a 57 Chevy, 68 Camaro, 64 Mustang..no problem..every single part is availible new and you can literally build a 2024 100% brand new version from the ground up with repro parts.

 

[75SV1]

I had a harmonic balancer go bad. I hope you caught it in time. Another thing I look at with XJs, is the rear steel brake line. I replace them with the prebent SS lines.

 

[asymptonic]

If you have not yet done that harmonic balancer job I would expand the scope to include a new timing chain and a new chain snubber. That snubber is another piece of rubber which will by now be as hard as plastic. And of course, while doing that job you will want to replace the front crank seal.

You have not mentioned which seals you have replaced over the years. Not only are seals important for keeping the good stuff in, but also for keeping the bad stuff out. Axle seals are where that is most likely to be an issue, especially if you ever do any water crossings or boat launches. The cooling effect of the water can create a vacuum, sucking in the water and whatever sediment is in it.

Other seals which don't get much attention are the body seals. Leaks around the windshield and doors lead to rusted out floor pans. Leaking window wipers (door windows) lead to doors rusting out from the inside (I haven't seen this to any great extent on XJs, but I have seen a lot of it in older GM vehicles--give it time and any vehicle can have issues).

Also take a look at the rubber lines going to your axles. If you have not replaced your brake hoses for the sake of a lift odds are those are due. And then the axle vent lines never seem to get any love, and those share the same issues as the rest of the axle seals.

Those are what come to mind off the top of my head.

So unfortunately I replaced the motor 50k miles back with a Jasper, which has worse gas mileage and low oil pressure. I regret it, as it was probably lifter tick or at worst a cracked piston skirt but as it was my only vehicle I panicked and spent the money on it. What I'm not clear on is what of the above might have come with the 'new' motor.

Apart from that, rear axle seals are for sure new as of 2 years ago, body seals are good especially around the doors, and I'm in Texas with just about no rust, certainly nothing beyond surface rust that I can find. Brake hoses I'll have a look at, but getting under there regularly nothing has jumped out at me as looking bad. Axle vent lines are a good call, will check those.

 

[Anak]

I am surprised that at 50K your balancer would fail. Or did the new motor not include a balancer?

If that balancer came with the "new" motor (and considering the fuel economy and low oil pressure) I would be planning to build another motor. I would pull a junkyard motor and rebuild that while you can do it at your own pace (i.e. before this "new" one puts you right back where you were 50K miles ago).

 

[75SV1]

I don't know what Jasper's warranty is. Also, time as to when you replaced the motor. Still, as above, at 50K for a harmonic balancer to fail, is pathetic. I'd send an email or call Jasper. Worth a try.