So I was having trouble with the serpentine belt on my 06 STR where when was hot outside? I would hear the belt squeak periodically and I would notice that the pulley on the compressor seem to stop momentarily when it happened. I have another thread posted about that.

I figured it was the compressor clutch or maybe even the idler tensioner getting loose and letting the belt slip but it showed it’s ugly face

The belt snapped when my wife was driving the car, I went to look at it and reached down to grab the pulley on the compressor and noticed that it was frozen solid. The pulley. would not turn it all.

But inside of the pulley, where the clutch is that spins the compressor rotates is free as can be.

How can the pulley be frozen solid if I can turn the compressor clutch and by extension the AC compressor??

It doesn’t make any sense the pulley rides on a bearing right if the clutch spins that means the bearings not frozen so that means the pulley should spin correct or am I not seeing something?

Question 2- is it possible to replace the AC compressor clutch/pulley with the compressor still bolted in the car if I remove the stuff that’s on top of it to get down to the bolt that holds it on the compressor? If I can replace the compressor clutch and pulley without removing the compressor, I can repair it on the street. If not, I have to have it towed home and I don’t want to do that.

 

This is certainly a strange one.

Any idea if the clutch coil has a metal or plastic case? With either material, the coil is fixed to the front of the compressor and obviously doesn’t rotate. But if plastic, I wonder if it swelled up due to overheating and is now jammed inside the pulley.

Had a distributor pickup coil (different vehicle) swell up upon failure. No mechanical jamming, but the plastic case was quite distorted and cracked.

 

the pulley spins on its own bearing seperate from the compressor.....the lockup between the 2 is of course the plates....if the pulley bearing fails the pulley seizes....the clutch coil to pulley spacing is very tight so any wobble will be deadly....to replace as a side of road job i dont think i would.....the subframe is right in line with the compressor....it has to come off or the engine has to be raised to get that clearance....even then i do not think you could get the clutch off....either way it is a home job i feel.....taking the compressor off is the way to do it.....i just replaced my compressor a couple weeks ago and had a good look at all that stuff...i actually took my clutch off to save it....the hard part would be there are 2 snaprings that hold things on and i do not think there is enough room to work leaving the compressor on the car....if i were to attempt a roadside repair i would drop the small subframe and then it would be doable, i think....working from the bottom

 

here is what you are dealing with see how the outer portion of the clutch has splines...that is what drives the compressor when clutch engaged.....also you see how the pulley and its bearing are independent of everything....only locking up when the coil is active and slams the drive plates together....those snap rings hold the pulley to the coil and then that assembly to the compressor body

 

more exploded view to help. You see the pulley has a pressed in bearing. That is what failed on yours i think

 

here is the nose of the compressor so you can see how it all nests together. The compressor having its own bearings too

 

Yes scott. You are accurate. Last night after posting this question, I went out and looked at my spare compressor that I have sitting on the shelf. I unbolted the nut (or more accurately, I unnutted the nut) and pulled off the clutch and the pulley bearing assembly to have a look

Sure enough you’re right a bearing and that bearing inner diameter mount to the compressor housing so that bearing can freeze up and affect only the pulley from turning. Which makes a lot more sense now that I think about it.

so I attempted removing the clutch employee from my spare Jag to see if it was physically possible to come down from the front and get the part off. I did get that off along with the clutch, but trying to get a set of snap ring pliers inside the recessed area to remove the pulley. Anne Marie was impossible because of the orientation of the snapping. The snaring was turned. It was behind the sway bar so I couldn’t get it from the front.

Happen to be situated such that the end of the snapping Work at the top I could probably gotten it off, but at least in the spare Jag, it was down towards the bottom and I could not twist the snapping to the end up where I could grab them

So I had towed. And instead of just replacing the clutch I’m just got a new compressor with clutch under warranties so I’ll just replace the whole damn thing again.

looking through my receipts, I found a piece of paper which describes a fairy making for the clutch bearing, which basically says that if you do not have sufficient voltage to the clutch or do a lot of short cycling of the clutch, it could overheat that bearing to point the grease spits out of it, which can lead to not bearing failure and lock up, but also it could change the shape of the front compressor housing with the bearing mounts. Beasley says if you have a situation with the bearing melted down, don’t just replace the clutch because it might have an out of round surface on the front end of the compressor.

 

The only other option i can think of is that if the same thing has happened to another member and they figured out the belt length without th ac in the loop. Then you could drive it no problem

 

Heres that technical message about the pulley bearing. Its good info

 

I'm extremely concerned here. I was thinking the pulley bearing’s inner diameter rode directly on the compressor shaft. I’ve had other compressors apart and that was the arrangement. With that arrangement, with the clutch clamped down, there is no relative motion within the bearing.

But now I understand this compressor has a stationary protruding sleeve where the bearing sits. Unfortunately, this raises the disturbing possibility that I was the W word. I cannot be held responsible for any calamities that might result, such as the Earth spinning off its axis, earthquakes, famines, a Nickelback reunion, etc.

 

More thoughts on the locked up pulley:

Was the bearing or compressor making any unusual noises before the failure? I’ve had several bearings growl or rumble as they started walking towards the light. Those were sealed bearings still retaining their own oil supply, succumbing to normal wear and tear. No drastic failure there, just some slop and/or noise.

However, I’ve only had one lock up completely. That was inside a transfer case. It was not a sealed bearing and was lubricated by the unit's oil supply. It never made any noise that I could hear, until it violently seized and spun in the housing. A post-mortem found a blocked oil passage, leading to oil starvation. I suspect the failure was rapid once starved for oil.

Where is all this leading? For a sealed bearing to fail so drastically, I think it would have to lose all its lubrication. Was the area covered in oil from a leaking bearing? If not, I’m still leaning towards my swollen clutch coil theory.

Of course it’s all a moot point as the fix will be to replace the whole compressor/clutch assembly. But equally important is to come up with a conclusion where I’m not the W word and work backwards from there to make the clues fit.

 

follow the jpec manual and it will be easier from the bottom....when you get he compressor unbolted shove the line towards the engine and it will catch on the frame rail....then you can wiggle it straight back

 

If anyone else is Jagging on an extremely tight budget and needs to bypass a broken AC pulley and/or pump like me:
You can bypass the X308's aircon pulley with a 7pk2200 belt. Just follow the same loop and skip the AC pulley. Works flawlessly. I also tried a 2155 (too tight to go around the tensioner) and a 2250 (too loose and flops around horizontally). The 7pk2200 is pretty hard to find but it works flawlessly and has the same fitment around the tensioner as the stock belt Just found this hunting around. I think the x308 has the 4.2. Maybe an option to get the car going. Just found it has the 4.0. So i guess no dice

 

I've had the pleasure of replacing mine, twice. Both times on the garage floor and a job over several days.
At least as a RHD vehicle, no need to drop the power steering.
A lot easier second time around and dropping the bumper did make the job easier.
I figured reconditioning the original unit would be the way to go, but these compressors don't recondition well; only lasted 3-4 months.

Second time around I bought an aftermarket far east made unit but from the premier AC supplier here. Which raises some question, have there been several different aftermarket manufactured units made, or all from same factory? Can you tell them apart?

 

There are some made now that do not have the plate on the back because the piston valve has been eliminated. Dont know brand but i have seen brutal post a pic. I just put a brand new nissens on my car

 

Ive been lallygagging and dreading doing this swap out. Got the car up on the left every time I go under there look at that damn tight squeeze for the compressor right lose all hope but today’s the day I’m down to one car it’s drivable now which is my hellcat and I hate to say it, but I hate lending it to my wife, her car gets repaired from a previous accident

The comment about thinking that the pulley bearing rides on the compressor shaft itself, yeah, that’s what I thought too but surprise surprise that’s not how it worked one thing got a look at it and boy is that clutch and pulley smoked. The metal on the side of the pulley rim is from the heat. I don’t know if I mentioned it before, but this has been making a chirping sound every now and then when it gets hot outside and theres more loading from the compressor. so it’s been slowly melting the grease out of that sealed bearing over the last two years. and as that technical note says it’s probably because I’ve got a voltage issue going down to that clutch. I have to check on before I destroy clutch number two.

so yeah, it was making noise periodically. I’d hear it squeal now and then and when looked down at the compressor pulley (hard to see with all the crap in the way ) and it looked like the compressor would stop turning. I incorrectly just assumed that the belt was slipping because I figured the tensioner was bad. so I had bought a tensioner and hadn’t put it on yet and when this happened. Turns out the tensioner was fine, but I’ll replace it now that I’ve got everything out to do the compressor
.

 

Is the old compressor still installed? You can run some electrical tests from the relay socket under the hood. This will test the clutch coil and all associated wiring.

See post #5 in the troubleshooting guide for details. Specifically, check the amp draw as that will be the best indicator of the clutch coil’s performance.

Have you inspected the compressor clutch relay? It’s easy to pop the cover to look for evidence of arcing, which will severely reduce the clutch performance.

 

Yeah, testing the voltage at the compressor now there’s up on the lift is a pretty good idea. It’s still installed in the car, but as for the relay, I did swap it out to a different one and it had the same problem. In fact right before it froze, when my wife was driving the car, she came home and said it was making noise and it was, and when I looked at the car, i saw the compressor was running. I said turn the AC off. She said it is off. I said no it’s running.

that’s when I pulled the relay. But it was after she parked it. I never went back to look to see if the thing was spinning after that.

Call that a missed opportunity

 

Check out the heat on the pulley and clutch! It SMOKIN!!

 

so unfortunately, I already sucked all the gas out of the system, so i went ahead to try your test but using a slightly different method

at first, I got an old relay and I just shoved a piece of wood (end of a toothpick) under the relay contacts to close them. It was an easy way to close the contacts to measure the voltage on the compressor clutch wires with no gas in it. but it instantly blew the fuse. I replaced the fuse just to make sure it wasn’t something stupid that I did and it blew a second time so I checked the resistance on the compressor clutch coil and it was 0 ohms. A dead short. so I think during the meltdown the compressor clutch melted

Measured the resistance of the coil on my new compressor I got and it was about four ohms. definitely not zero. So I grabbed the closest power resistor that I had. I had a 2.5 ohm and a 10 ohm so I cut the wires on the connecter wites to the clutch for the old compressor and I just put the resistor in with some extended wires coming out to measure the voltage easily. I measured the voltage with a jumper in place of the relay.

13.3 V measured at the jumper in the fuse box. I l measured 13.08 at the wires at the resistor at the compressor connector so not too bad. I don’t think that’s the problem. Remember thats with a 10ohm resistor in place of the coil. Also measured the amps and was close to what youd get with ohms law. A little less. 1.18A. I’m wonder if that means that I’m only getting 11.8 V across that coil under load. But I can’t explain the discrepancy. It could be that I just wire wrapped the wires that I cut from the compressor coil and wrapping around the end of the resistor real redneck engineering like. The side of the resistor in and try again. I was using my fluke with the meter and series with the circuit. I just put the probes in place of the relay and measure the current at the fuse box. But current is current, so it should be the same all along the line unless there’s someplace bleeding off some power, but I don’t believe I have that checked the lines to ground before the test (lol actually after I blew the fuse. Twice)

The problems with this test is on the R version there’s no room to get your hands on the connector to back probe it when it’s installed on the compressor because it’s so tight. Theres that extra frame and there’s some hoses that are going through the panel access in the wheel well. I couldnt probe the connector at all with it installed so I don’t know how I could check it without using my test resistor. And I’m not gonna do that

on my new compressor