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Clutch Bearing Replacement Dodge Stealth

edge on Tue August 10, 2010 9:42 AM User is offline

Year: 1994
Make: Dodge/Mitsubishi
Model: Stealth RT/ 3000GT SL
Engine Size: 3.0
Refrigerant Type: R134A
Ambient Temp: 90
Pressure Low: NA
Pressure High: NA
Country of Origin: United States

The clutch bearing is making a lot of noise with the AC on and less noise with the ac off, so it sounds like it needs to be replaced. The compressor is a Mitsubishi MSC105CVS and still blows cold air great - just as it did before the bearing problem. Can the bearing be replaced in this clutch and if so, is any bearing make preferable - I see Santech, Four Seasons, Nachi. The dealer sells a clutch replacement at about $250, so I am willing to put in work to replace the bearing.

The clutch gap it is on the upper limit of the spec at .020" - spec is .010 - .020". A new replacement belt was tensioned to spec. The clutch pulley spins freely by hand, but I have heard some clutch bearing in these units seal goes bad and then lose the grease. No oil, grease or dirt is around the compressor clutch or fittings.

Thanks.

Edited: Tue August 10, 2010 at 2:40 PM by edge

Cussboy on Tue August 10, 2010 11:02 AM User is offline

Wouldn't the AC clutch bearing be "locked up" and not turning when the AC compressor is on? Noise when AC is off seems indicative of a bad aC clutch bearing. Are there other pulleys like idlers along that belt?

Wait for an expert to chime in here....

edge on Tue August 10, 2010 2:11 PM User is offline

Quote
Originally posted by: Cussboy
Wouldn't the AC clutch bearing be "locked up" and not turning when the AC compressor is on? Noise when AC is off seems indicative of a bad aC clutch bearing. Are there other pulleys like idlers along that belt?



Wait for an expert to chime in here....

On this design the AC clutch pulley and bearing spins all the time. The pulley is mounted to the outside of the clutch rotor, the bearing is pressed in the rotor, the inside bearing bore is mounted to housing snout of the compressor. The pulley freewheels when the clutch is disengaged and drives the compressor when the clutch armature plate (disk) is engaged, which is mounted to the AC compressor shaft. I think the noise is less, but not gone, with the AC off because there is less load on the bearing. I did not see any clutch slipping with the AC on.

Yes there are two idlers on the belt. I checked them with a stethoscope/hose and the noise sounds like is coming from the AC clutch. However, the bearing noise did not transmit down the compressor housing.

Will wait for an expert feedback.

Mitsu MSC105CVS

Edited: Tue August 10, 2010 at 2:19 PM by edge

mk378 on Tue August 10, 2010 2:29 PM User is offline

I'm far from an expert, but the first thing I would do is remove the belt and spin all the pulleys by hand to see which one is noisy, also try to wobble the pulley side to side to see if there is slack in the bearing.

Bearing replacement is very straightforward if you are able to find a supplier and purchase the bearing alone instead of part of a clutch kit. Remove the clutch plate, remove the snap ring, and pull the pulley / bearing assembly off with a gear puller. Press the bad bearing out of the pulley and press in a new one.

Edited: Tue August 10, 2010 at 2:30 PM by mk378

ACProf on Tue August 10, 2010 3:58 PM User is offline

Quote
and pull the pulley / bearing assembly off with a gear puller

I always get shivers when I see that message. A regular automotive gear puller will center on the input shaft (not good). I've been brought systems with split open ends on the compressor shaft, flared ends that you can't get the nut back on, and flared end shafts where you cant get the nut off. All it takes is a stuck bearing center and chances are good for this to happen. All are basically fatal to the compressor.

Even if the shaft end doesn't get ruined, putting pressing pressure into the compressor by the shaft will affect the internal bearings and surfaces and lead to problems down the road.

There is a special AC pulley puller kit that puts a fitted metal cap (sort-of like a 1/2" socket with no hole through it) that fits over the shaft and bottoms on the case nose and protects the shaft. I'm sure Tim must have the kit you need.

Check the local chain store for the kit for loan.

Mastercool Tool Set - See Part #90455 - Page 37

Catalog

Edited: Tue August 10, 2010 at 4:42 PM by ACProf

mk378 on Tue August 10, 2010 4:13 PM User is offline

You make a good point there. It's certainly best not to push on the shaft that way especially if the bearing doesn't want to come right off.

Do make sure that the cap like piece is the proper size to engage the metal nose of the compressor and doesn't just push on the seal, which is certain to damage it.

iceman2555 on Tue August 10, 2010 9:55 PM User is offlineView users profile

Prior to purchasing tools and bearing, suggest to complete evaluate the clutch assembly. The normal failure of this bearing is associated with an over heated clutch. If this is the case, considering the compressor and its failure history the repair maybe a bit more intensive.
The failure of scroll compressor can contaminated the system to such a point that it may be necessary to replace the entire AC system. The Honda CRV is a prime example, however, this vehicle utilizes a very similar compressor.
Remove the compressor and thoroughly inspect not only the clutch assembly, but also the amount and condition of lubricant that drains from the compressor. If there are metal fillings or if the lubricant is dark discolored it maybe that the unit is past repair.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

edge on Tue August 10, 2010 10:45 PM User is offline

Quote
The normal failure of this bearing is associated with an over heated clutch.
What signs of clutch overheating should I look for - scoring and discoloration on the disk?


Quote
if the lubricant is dark discolored it maybe that the unit is past repair
Would a dark lube show thru the sight glass ?

iceman2555 on Tue August 10, 2010 11:44 PM User is offlineView users profile

Normally the clutch will be discolored...some turn a rusty brown color....the drive plate paint/coating will blister. When you remove the drive plate....look for heat marks in the clutch (metal bluing) or excessive slippage marks on the drive and pulley fact.
Dark lube may or may not be indicated in the 'slight glass'. We have seen systems opened and the compressor was heavily contaminated and the drier or accumulator may not indicate the same conditions. The key is a sufficient amount of refrigerant to move the lube through out the system. But normally..yes.


-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson



Edited: Tue August 10, 2010 at 11:45 PM by iceman2555

edge on Wed August 11, 2010 10:06 AM User is offline

I did a quick check of the clutch externals and pulley and don't see any signs of overheating. I also rotated the compressor with the drive plate disk and didn't feel any binding. But, I'll disassemble to check this more thoroughly.

If it turns out to just be a bad clutch bearing are there any recommended brands? I believe rotor is peened to hold the clutch bearing.

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