AC Vibration

[JeffU]

This weekend I replaced my radiator, water pump, thermostat and serpentine belt.
The new belt is a Good Year Gator Back. I adjusted the belt to 160 and rechecked after driving a couple of hours. The tension is now at 140.

I have always had a slight vibration when the AC clutch engaged, But now it is much more pronounced .

Any thoughts on what could be causing this increased vibration ?

Thanks.

[jeepsrock]

The belt tention is defined as 185 for new belts and 170 for belts that are used or have been in use for more than 15min.

Once your tention is ok, if by vibration you mean engine idle well then i have the same problem as my AC is on my idle is a bit rougher.

Pete

[JeffU]

Pete,
I am using a Krikett gauge from NAPA. If I am reading the gauge correctly, I get a reading of 110 from AC to water pump. From the water pump to PS pump it reads 140.

The idle has always been rougher with the AC on. But this is a vibration you can feel and resonates through the interior.

[JeffU]

I have never replaced the serpentine belt on an XJ before. I find it strange that I have only 3 or 4 threads left at the top of the adjustment bolt. I would think this is where I should be on a very old stretched out used belt, not a brand new one.

[JeffU]

Still needing some suggestions. Could a bad AC clutch bearing cause this vibration ?

[jeepsrock]

i am gonna suggest a bad idler first then i would look at the clutch for the AC.

pete

[JeffU]

Vibration found !

Not the AC clutch or clutch bearing but a chip missing from my auxiliary fan blade. I must have damaged while R&Ring the radiator and water pump. Now I just need to find a replacement fan blade.