Hello guys,

Something causing a bad vibration in the car at idle, and I have narrowed it down to the belt or one of the pulleys. I am thinking maybe my harmonic balancer has failed, but the belt pulley tensioner does seem to vibrate an awful lot. I was able to buy a new tensioner puller and belt but I had to get the harmonic balancer used, but I want to try and gauge what I will be getting into before I dig in…the car just hit 100 miles and I guess it would be normal for a harmonic balancer to fail, but is it common in the 3.0 ?

any help greatly appreciated

 

It's a while, since I removed an harmonic balancer. I think that yes, it is possible that the harmonic balancer itself may be damaged - if I am not mistaken, a harmonic balancer consists of 2 parts, which are bonded together with a layer of rubber, and this rubber can break. However, I'd say that this is rare. Also, the harmonic balancer sits on the crankshaft, and there is a bearing for the crankshaft - actually, there are 2: One at the front (where the harmonic balancer is) and one at the back (where the Jatco JF506E transmission attaches to the flywheel - which in case of the X-Type actually does not (as in other cars - store much much rotational energy, as the X-Type flywheel as bugger-all weight (i.e. they are very lightweight).
I can tell you: if it's the rear bearing, you'll have fun! That means removal of: TC (transfer case), subframe, transmission (also out from underneath), then then you get to the flywheel and it's bearing. All this will take forever, Just for the removal of the infamous upper left bolt of the catalyst bracket you will need about 3 days (if you are good), as this includes painful experimenting with welding a special tool for this purpose.

So hopefully it's not that. The bearing of the harmonic balancer would be hard enough to get to, but if you are really lucky, it's just the bearing of an idler pulley, where the drive belt runs. One of them is the idler of the tensioner and there are 1 or 2 more idlers (I think 1), and those 2 (this and the tensioner pulley's bearing) are most likely to fail.

Maybe you can hear a high pitched noise (similar for a squeaking drive belt and you would want to spray belt-anti-squeak spray onto the belt (which btw, would be a futile exercise in any event).... This noise would be a failing idler bearing. I used generic bearings to replace the originals. I even reused the tensioner and just replace it's idler - but caution there!!! The bolt the fixes the pulley of the tensioner has a LEFT-hand thread, i.e it opens CLOCKWISE!