AC pulley

I believe the pulley for my AC is bad as I can spin it by hand (with the belt off) and can hear clicking noises as it turns. My theory is that with the belt on and running much faster than I can spin by hand, the noise becomes amplified to the point of a nasty screech. (The belt is fairly new and was changed by a mechanic before I decided to start learning this stuff myself.)

I looked through the parts list pdf file I grabbed awhile back and found part number 83501845 ("PULLEY, Clutch Drive"). Searching a mopar parts site, I find a price of around $140.

1.) Do I have the right part? Is this the part that the belt sits on?
http://partimages2.genpt.com/partimages/172220.jpg
(Middle part in this photo. They want $269 for all three pieces here.)

2.) Why is it so much money compared to say, an idler pulley?

3.) I think it is the bearings that are bad. Is there some way to just replace the bearings and save some money?

TIA

1990 XJ 4.0L w/AC w/PS

furrymcmonst said:

I looked through the parts list pdf file I grabbed awhile back and found part number 83501845 ("PULLEY, Clutch Drive"). Searching a mopar parts site, I find a price of around $140.

1.) Do I have the right part? Is this the part that the belt sits on?
http://partimages2.genpt.com/partimages/172220.jpg
(Middle part in this photo. They want $269 for all three pieces here.)

2.) Why is it so much money compared to say, an idler pulley?

3.) I think it is the bearings that are bad. Is there some way to just replace the bearings and save some money?

TIA

1990 XJ 4.0L w/AC w/PS

Click to expand...

1) The aircon compressor pully contains a magnetic clutch, so it's probably the right part. No, it's not cheap (and idler pully is stamped from sheet and has a $5 bearing in the middle - which explains the difference...)

2) Refer to (1)

3) The bearings are usually in the compressor itself, and the compressor usually needs to be dismounted to service them. This means draining the system, and having it purged and refilled afterwards. Spendy. The pully can usually be removed with the compressor in place, but it typically requires a "specialty tool" to do so. Probably easier to just replace the compressor in toto if the bearings are shot.

5-90, Thanks for the thorough response. I checked prices on new compressors and it is definitely not cheap. I can't believe how expensive they are and I'm also missing the compressor so that adds to even more.

For as little as we use air conditioning in the Pacific Northwest, I'm thinking of trying to remove it altogether. There must be some way to remove it and then substitute an idler pulley. I'll search the threads as I'm sure something like that has been covered.

Happy Thanksgiving to you.

furrymcmonst said:

5-90, Thanks for the thorough response. I checked prices on new compressors and it is definitely not cheap. I can't believe how expensive they are and I'm also missing the compressor so that adds to even more.

For as little as we use air conditioning in the Pacific Northwest, I'm thinking of trying to remove it altogether. There must be some way to remove it and then substitute an idler pulley. I'll search the threads as I'm sure something like that has been covered.

Happy Thanksgiving to you.

Click to expand...

Yes, there is an idler pully for that - it mounts in the same place as the compressor, on the same bracket. You can probably find it in a junkyard. (If you find two, get them both and let me know what the second one cost you. I'd like a spare...)

You'll probably need to replace the bearing. I think it's Timken #203FF (or equivalent,) costs $5-7, and you can press it in and out with a shop vice. Get the pully and the upper bracket it's mounted on - you shouldn't need the lower bracket (since it's the same with or without A/C.)

5-90, I went to the local used jeep parts place (http://www.oly4x4.com/) and purchased a bracked with a pulley that fits in the same spot where I have removed the AC compressor from. It fits right where the two longs bolts are that held the compressor.

For anyone interested, here are the Jeep part numbers. (For 1990 XJ)
Bracket: 5300 2904
Pulley: 5300 2903
Bushing: 3300 2201
Bolt: 3420 1869

They only had one of these and it wasn't much cheaper than buying new, if at all. $65 for bracket, pulley, bushing and bolt. At least I can theoretically get this thing up and running today. There is quite a bit more space with the compressor removed, too.

Update: After replacing the AC compressor with an idler pulley, the noise didn't go away.

I decided to put a new radiator in and since there was so much space while it was out, I put my hand down and spun the alternator. Voila! The noise was plain as day and even my wife said it sounds like the noise we were hearing. I know, I should have checked that when I put the new belt on but the noise had the apperance of coming from the top of the engine which is why I replaced the idler and converted the AC to an idler. It must have been an aural illusion.