Harmonic Balancer Squeal

I have a 1994 XJ 4.0 with the AX-15, bought used from a friend, mainly stock, 178,000 miles, daily driver.

I did swap in a 1999-2001 intake manifold and created a 'custom' belt drive to work with the different power steering pump mounting found on these manifolds.

It had worked fine for a while, then the front accessory drive started to squeal, loudly and is entirely RPM dependent.

So first I replaced the tensioner pulley that I had added, this is below the power steering pump, I used a 1995 YJ style mounting bracket. This did not work.

Swapped the fan clutch, because it sounded similar to the noise my 1991 S-10 made when the fan clutch failed. No luck.

So I went after the bearing that supports the fan hub. Went throught the whole process of creating a fixture to press off the fan hub and press out the bearing and bought an NSK 856886 bearing from Motion Industries. No luck.

This XJ is currently non A/C, so I swapped the pulley that taked place of the A/C. Nothing, still squeals.

I didn't try the alternator as I had replaced it a few years ago when my friend owned the XJ, so it does not have too many miles on it.

Replaced the power steering pump next. No luck.

So this left the only spinning parts not replaced as the alternator and harmonic balancer. Not sure how the harmonic balancer could squeal. it did show any signs of deteroration or rubber loss and only had a bit of wobble to it. But I was out of ideas. So I swapped with a Chinese speacial from Autozone.

Squeal gone, runs great! Still not sure how the balancer could cause such an extensive squeal, without showing any signs of obvious deterioration.

Any one else run into this before?

Chris
1995 YJ
1995 XJ
2004 WJ

I'd say it was probably the belt, since a harmonic balancer is directly bolted to the crank and has no bearing or moving parts.

OR

The old balancer could have worked it's way back enough to rub on the timing cover, and since it was wobbling...it shouldn't wobble at all. I can't even tell if mine is turning even with a light on it. Did you look at the timing cover when you had it off??

I had the exact same problem with my xj last fall. I replaced the belt, idler, alt, and water pump. It still made noise so I replaced the balancer and it fixed the noise.

Too bad you replaced all those parts before finding the source of the noise! My balancer was making a "chirping" noice...was the wobble making it rub the timing cover.

The chirp noise is usually a misalignment... I did the same exact thing by replacing everything with a little play and ignoring the balancer. Came accross this video http://m.youtube.com/#/watch?v=cRd6LQLf0_0&desktop_uri=/watch?v=cRd6LQLf0_0 which led me in the right direction.

Would have been a great opportunity to use a three foot piece of rubber hose, one end stuck in your ear and then move the other end around the engine--being careful of moving parts--and you could have isolated that squeal, saved some blood, sweat, tears, and bucks.