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Compressor clutch failure

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    Compressor clutch failure

    Had a clutch failure on an A-6.
    A little backround.
    System was rebuilt last summer and worked until I had a deer strike last winter. In the winter I replaced the clutch pulley as I didn't have the right one at 1st. The system takes the less common 5 5/8" x 1/2" belt pulley that was used in the 60's, but well into the 80's on ag equipment. I originally could only find the 5" x 7/16" belt pulley. When the correct pulley was installed a new pulley bearing was installed at the time.
    When the deer strike happened, it was well below zero, and although the condenser cracked, it was not a sudden release of pressure and the pressure was very low anyway due to the cold temps.
    Because of the slow release, the lack of any evidence of oil escaping, when the unit was repaired, no oil was added.
    Last week it got warm enough to use the A/C and had some belt squeal when the compressor tried to start, but once it was going it cooled well. When I stopped, I tightened the belt and all was good... so I thought.
    The next day, it quit working. When I got home I found the clutch in pieces and the pulley bearing shot. The belt never stopped turning and there was no belt squeal. The system has a high pressure cut-out and two low pressure safety cut outs. (one each on the high and low side)
    Two scenarios come to mind, either the clutch started slipping and heat built and burned the clutch and bearing, or the bearing failed and took out the clutch. The reason I don't suspect the clutch slipped is, A) it never had before even at much higher head pressures, B) it was cooling well and the truck has an oversize condenser and the head pressure is always low.
    Oil slugging of the compressor is a possible cause of clutch failure, but with no oil being added to the system since when it was working well last summer, I can't see that being the cause. Any blockage in the system would trip the high pressure safety on the compressor outlet.
    I'm leaning toward a failed bearing however unlikely that is, as the cause. Once the bearing failed and the pulley was no longer held in tight alignment, the clutch slipped and rapidly failed due to heat build up. The epoxy in the clutch was burnt to the point it fell out, and the bearing was toast. The rubber coupling bond to the driven disk had separated (looks to be a heat related failure).
    All indication are the compressor is fine, it turns over by hand easily but not without a little resistance, as one would expect with a charged system. The pressure shows ambient temp, so I don't believe any loss of refrigerant. The low safeties are very effective and shut the system down before any significant loss would be detected.
    New Ag clutches are available, but cost as much as some rebuilt compressors. Unfortunately the heat damage is so severe that no part of the clutch is re-useable. Amazing that it made it the 1000 miles with the bearing in taters.
    I guess my question is: has anyone come across a bearing failure as the PRIMARY cause? esp a new (less than 6 months old) bearing? Most times it is a slipping clutch and the related heat that takes out the bearing, in this case I don't think that is what happened.

    Bummer! An A-6 all messed up now is a tragedy. To the question "Can a bearing be the primary cause?"

    With assorted anything taking a load YES I've had to conclude that. Metal just changes it was so hot just not the same to deal with again.

    Oddly this one (long read hope I'm reading it properly) just kept compressor engaged for that 1,000 miles managed to make it! Assorted temps and condtions would say it must have choked on liquid so somehow belt or slipped somewhere just didn't burn into flames?

    As always it's right now what to do. Whole rebuilt or just clutch same costs?

    I'm not thrilled with the rebuilt anything nor new bearing if not clearly marked where made possible that there's no regard to which metals to use just make the shape and sell it even without markings want to vomit at this quality problem.

    Have to leave this up to you just maybe find a whole spare unit if the rig you use or some NOS parts the hard part is they are out there but not inventoried on the web so near impossibly difficult.

    For pulley issues on a side note this stuff is now a nightmare for me assorted equipment does use 5/8th "V" belts I did start finding some stuff at a place "Tractor Supply" in person but is not and doesn't look "automotive" (your rig) grade rather slower speeds would probably work not highway long use as a guess so far.

    Hit me off site Cornbinder I need to take a ride to CT and see if I can acquire whole new A-6s and at what cost. Not a chance if I don't go there, ask and look at what that place is like now and if any inventory is clear on this always was ongoing with mountains of stuff bought up as scrap metal new in boxes!

    Need time to do this and the info on what to ask for it's just 44 miles away but may take round trips do the math will take tons of time,
    MetroWest, Boston


      May be I wasn't clear, the clutch totally destroyed, but the pulley and belt managed to stay turning until I got home, Pulley was "wobbly" as the bearing was in pieces. Made it hard to get it off the nose of the compressor.
      The pulley used is one that GM used in the 60's with a 1/2" belt size (most of the stuff from the 70's on use 7/16" belt) and the larger pulley diameter of 5 and 5/8" as opposed to around 5' that most Ford and GM cars used since the mid 60's. I have a 6 3/4" pulley but that would slow it down a fair bit and there are clearance concerns.
      I have found that many AG equipment used the same pulley that I need, and there are suppliers in my area that claim to have access to them new, not just the pulley but the whole clutch with coil. The Coil is about the only thing salvageable from mine but would replace it to be safe. Same places also claim to supply new and rebuilt compressor/clutch units. I don't know who is reproducing the A-6 (may be Compressorworks) so not sure if new is any better than their rebuilt.
      The compressor seams fine. I can turn the shaft and feel it compress, as the gauges show normal static pressure in the system.
      I guess I'll shell out the $200 for a new clutch (with dust shield even!) and see what happens. I can buy a whole rebuilt with the correct clutch for around $280, but would need the oil drained and PAG 150 installed, and not sure it would be any better than what I have on their now.
      There is a few cores on E bay up for sale, and I might pick up a spare to go through over the summer. Most have the wrong clutch, but if I now have a supplier for new clutches that isn't a problem.
      When I changed pulleys last fall, the one I put on was a rebuilt (I could see it had been "cut" to true it up) but I was the one who put in the new bearing in it, and it was a "National" bearing, I don't know the country of origin. As it is a sealed bearing, it is possible it left the factory with not enough grease and that is why it failed.
      John Deere, Massy Harris, and IHC AG equipment all used the A-6 with a few different pulleys, but all had the "chaff" package on the clutch to keep out the grain dust. Not surprising then that IHC used the same unit on their trucks as well.
      I got my 6 3/4" pulley from a bus supply house. I should have bought all they had 'cause the Corvette guy's think they are made of gold ( I think the only the real HP GM cars used them) and could have sold them on E bay for 10x what I paid! The 6 3/4 pulley is another real common AG size.


        I'm shocked it stayed as an acting pulley and didn't just fall off or DESTROY the shaft! YOU know these 100 X better than I would because they DIDN'T FAIL date back now to just having A/C was 1/3rd the cost of a car/trucks were trucks.

        So owned a couple mid 60's Cadillacs must have been those and some still monster Fords in the 70s - did I recall the tag said ''Frigidaire?" Another on a real Rolls Royce was that too that car was parts just left in mud I refused to mess with it in general.

        My only fear and know you can make the call on the compressor you have now is the clutch (new) really new good stuff or a good looking clone by now? I worry about mostly the bearing, quite obviously look at what just races did to hold up for you will the new be that caliber? Would you see the #s on even it if just (you tell me) a snap ring just taken off?

        Sorry to beat on it I've had new stuff on the counter took whatever bearing out and flipping thing was NG and showed my fav place the flaw NEW.

        So far I'm leaning to get the whole clutch, coil and all (heat should have wrecked that) and think You'd know being right there. I know you didn't hear it when driving so much figured it's so sound insulated you wouldn't hear much till parts were in the rear view mirrors :-) not funny.

        If asking me also know I didn't win those PowerBall super jackpots but would go that clutch you mentioned even if same price vs whole reman then you don't know "Jack" about it clutch or if done well - right?
        MetroWest, Boston


          On this truck, the A/C compressor is below my right foot, so I can hear it when the belt slips. I decided to take a chance and ordered a clutch. When it gets here I'll look it over.
          What I'm guessing happened was the bearing let go, the pulley canted so no longer flat to the compressor 1/2 of the clutch, so only the top portion was mated together and so slipped, and heat did the rest.
          A-6's are fairly bullet-proof as long as they have enough oil.
          I've had luck buying ones that a stuck from sitting, as long as the clutch is intact, and taking them apart and freeing up the pistons. Often it is just the mineral oil turning to varnish in the bores.
          I think on the old site, someone said that Compressorworks (Compressorwerks?) was cloning the A-6. It is why I didn't opt for the complete unit, that along with having discharge and recharge the system. Just the clutch I can do in place.
          If I can get a "core" unit with a clutch that isn't bad, delivered to my door for under $100, I figure it is worth the chance.
          Most times if the compressor locks up, either the three leaf springs in the clutch snap off or the rubber bond on the rubber portion shears, but there is no heat damage, this one had mostly heat damage.
          Last edited by Cornbinder89; 04-21-2019, 12:48 PM.


            I searched out "Images" also leads too places or things for sale and was another name making new A-6 clones with alloys said in the picture was 52% lighter? I don't want lighter I want WORKS FOREVER (I'm bad) stuff.

            Your wrecked one must have ridden on the best grade of hardened steel for bearing use it tolerated the abuse and probably better belt became loose but not fly off. Now with all the one belt set up ups for cars your are screwed right away A/C doesn't work and wont the engine is going to blow up too no other anything.

            Guess just wait till you have it and glad you can do it without removing compressor or all kinds of headaches.

            Story: It might have been an A-6 everything was ages ago now needed just a clutch (brother's car) and a pick-ur-own if allowed I did just take one off a car just in hadn't marked whole parts yet. THEY WERE TICKED OFF but left with it for almost nothing it was done already. Worked too and never touched that car again for a brother drove zillions of miles for his work but in his own vehicles.

            Your "rigs" as you put it bet most all not made to just expire over miles like cars for ages. That case I/we won that high mile game never got new but knew which set ups/layouts of vehicles with which drivetrains would likely do the 250K expected in no time most that's enough to count on all assorted reasons.

            Now I don't know how to brand name expected quality just by name. OMG the "brand name" gets sold off who knows then who did what? Stinks when you had favorites,
            MetroWest, Boston


              There are places that are making "special" cases that use I think a Denso guts that are aluminum case replacements for the A-6 that they claim are "bolt in" with no mod's to hoses or brackets.
              One of the reasons I don't go with the aluminum case compressors is they either have steel rings riding in an aluminum bore, which makes them a throw-a-way compressor or they try to use Teflon rings, and we all know about Fords experiment with that!
              I don't push myself, and I run around 90-100K miles a year on my rigs, so even if the compressor doesn't get used for 1/2 the year, the clutch bearings are always turning.
              The true A-6 is a cast iron bore, aluminum piston, steel ring an bronze "shoe" riding on a steel swash-plate and ball, with pressure lubrication, It is a work of art in a way. The piston "shoe" is a selective fit part, meaning you try a bunch of different shoes until you get the correct clearance.
              I'll try and get some pictures, but there is evidence that it was the bearing that failed 1st. There is un even wear on the compressor 1/2 of the clutch and the rubber has separated not only from the "pressure plate" 1/2 but also 1/3 of the driven 1/2 of the clutch, indicating it was rubbing at an angle while the compressor was stationary. Also there was enough heat to burn the paint off the pressure plate and the heat broke the epoxy bond all the way around on the pulley.
              I'll see what the new clutch looks like later this week. The place I ordered from wanted my Fed tax number? I guess they don't want to sell to individuals, I could see my state re-sale tax number (which they didn't ask for and I don't have), that is a new one on me. .


                OMG - no clone alloy stuff for your type use! Bad enough with cars now trucks are the cars thanks to a 10% Fed Sales Tax on cars, on the amount over $30,000 is well hidden. That's all a car maker really gets for a profit so call it technically a truck it's exempt from that snag now $30K isn't some luxo boat anymore but some insane high performance stuff was always up there but (off topic) where the heck can you really drive way over 100MPH and stay at that for long?

                Everyone sees the "Tractor/Trailer" rigs of course that moves 99% of everything however it got here to destinations inside each state city like Boston isn't serious about the horse and buggy days you did that out back (think of the names - alley cat for example) the road was for trolley use more! Oldest in the whole USA you can stuff that crap.

                I totally get the idea you expect a million miles before a major overhaul and do it again - right? Sleeved engines are to new specs, boring one out wrecks anything needed to be precise.

                So it's redone just did anyone make the real thing again or just the clones out of just what will work for so long? Can't answer that for sure.

                Anyway, good luck with the maybe of what might have happened to the compressor itself guess you really can't know for sure till it's working or just trying to?

                MetroWest, Boston


                  off topic, but you can, and I have wore out the bores that the liners sit in, then you have to overbore the block and inset a "salvage sleeve" into the block to bring it back to where it will accept liners again. My '42 IHC 3 ton truck with a 6 cyl gas (269 CID) has dry liners and can be "inframed" (the term for rebuilding while the block remains "in frame" or in the truck).
                  Believe it or not, my wife's '84 AMC/Renault had wet liners and could be in framed as well, the engine outlasted the body, so never had to test the theory


                    Still off topic: Yes IHC and AMC did get in bed (oh just smile) put some really great engines in bodies that couldn't last. Owned several IDK if "sleeve-able" as the cars couldn't be worth any serious engine work by then.

                    Of many a couple cars ended up wild deals and strong by AMC/IHC engines. 1960 Rambler 258 I-6, ''TUNNEL DRIVE'' couldn't kill the thing! Is anyone alive that knows what "Tunnel Drive" even is?

                    1976 Matador! 350? IHC V8 couldn't kill it either but OMG style of a "Road Killed Platypus" did do countless runs back and forth I-80 + I-90 to Denver. Managed to do 4 wheeling remarkably well just 2WD top of Mt. Evans*, CO, I think close to 14,000 ft. elev. OMG, could hold the car still while floored with a kite string! No air, no power! LMAO! *=

                    Was nice to be that young, adventurous and survive to tell about it!

                    Warning to high altitude wandering youth: DO NOT OPEN BEER MADE AT SEA LEVEL AT 14,000 FEET QUICKLY. The spray or explosion like a Roman candle was hysterical but wasted the beer! Just crack me up - there was life before these so called "Smart Phones" now glad there's no pictures of those times!!!!

                    Those were the days my friend, we thought they'd never end, we sang and danced forever and a day...……….(that's a real song) = > https://www.youtube.com/watch?v=y3KEhWTnWvE <
                    Last edited by Tom Greenleaf; 04-22-2019, 04:17 AM.
                    MetroWest, Boston


                      Mammas & the Pappas, if I remember correctly, Real popular song in the late 60's.


                        I still can't believe that went so many miles. Any clues on the compressor itself or shaft? I see what looks like ball bearings in 2 of the pics. Do you think that was just enough to save compressor. It's a maybe but you are there I'm not.

                        That song was done by several artists I think the one I put there was NOT the Mammas and Pappas and forget right now. Was on a roll with that post odd stuff. 1/2 the cars I had back then didn't even have a radio never mind A/C. They did quickly though it was easy the wires were hanging right there behind the plate over where one would go just add the antennae, holes for speaker front only was there too,

                        MetroWest, Boston


                          The pulley rides and a nose on the compressor, the compressor shaft comes up the center of the "nose". The compressor shaft was saved from damage. It isn't like the York, where the crankshaft carried the full load. Worse comes to worse, I can replace the front nose of the compressor.
                          The place that is supposed to be sending the "new" clutch hasn't updated the order and elsewhere I saw a "rebuilt" sticker. I don't know what I'm getting.
                          Yeah the bearing really came apart. There should be a spacer to keep the balls equidistant from each other is missing.
                          The crankshaft turns well, so don't think there will be a problem. The clutch is well designed and the rubber prevents off-set loads being transmitted to the small compressor shaft.


                            OK: I've done some NOTHING like this problem. Plain toss a bearing or a good used clutch, take the coil too almost free once just time and an Snap-On puller IDK where it is just where it should be. I'm familiar with the "cage" that holds bearings, ball or barrel types both do that just did a brake job with real bearings not sealed hubs.

                            Did lots of gap adjusting but it's been a while. Rebuilt one that came out worse than a shaft seal I wanted to fix so ticked off to find whole thing was less than the kit gave that up in a hurry.

                            Nothing in need that I know of need more time to fully test out ones in any question would only be a leak not a serious problem was hot enough just quick trick a couple no time and too cold to boost up yet.

                            Hope it works out now I'm ticked with all the junk I saved I thru those all out or got core charge $$ back if any quickly no more rebuilt ones, failure too much so new or nothing just do without I keep saying.

                            This one is all yours I didn't go there before did and still would for other things not compressors but this is the A-6 best ever no experience fixing them every last one out lived the vehicle they were in!

                            MetroWest, Boston


                              I don't believe anyone is making new stuff for the A-6, even if they say it is new. It seams that automotive got away from a 1/2" belt and larger pulley by about 1967, That make my use harder to find sources for. AG stayed with both the 6 3/4" and 5 5/8" pulleys.
                              I went with a "new" bearing and see where that got me!
                              I could retro-fit a York (CCI) or Sanden, but the CCI shakes so bad the brackets crack and the belts will not stay tight. Sanden and their like don't last and are mostly "throw away"


                                ? York ? Do you mean the one that looks like a lawnmower engine? RV-2 or what? Noisy suckers but worked! The clone game is wrecking the world. Your rig is beyond "truck" is automotive throw away junk, brackets and all, real high grade steel reinforced up to designed to absorb vibrations or shake and cause harm even the engines they bolted to assorted other things.

                                Back when I searched (ticks off my anti-virus protection to do it!!) the A-6 stuff was all alloy junk just made to bolt on but you know it's not the real stuff.

                                IDK - I just feel your pain with this......

                                MetroWest, Boston



                                  The York/CCI is the old Ford/AMC compressor, the replacement for the A-6 Is a modern Aluminum axial compressor with an "extended nose" to mimic the A-6 mount and a common "GM Pad" rear cover. I don't know who makes the main body, if it is Denso, Sanden, Seltec or someone else.
                                  replcacement for A-6
                                  Attached Files
                                  Last edited by Cornbinder89; 04-24-2019, 11:59 AM.


                                    Late to comment. Looks too aluminum/alloy to last forever. For a car I could see it not for what you would use IMO you'll be back at that again. I might try (never have) add a filter so you save the rest of the system,
                                    MetroWest, Boston


                                      Remember this was a clutch failure not a compressor failure, no indication of a problem with the compressor. A-6's have a fine mesh screen in the suction port to catch any debris, along with a parallel flow condenser, it think it would stop any "chunks" if they ever did happen.
                                      I've been waiting for the new clutch and it hasn't shown up yet, I may have to get my credit card company involved, as the phone number goes to voice mail and he hasn't returned E mail. This is from a company that has a website and seams to deal in replacement tractor parts.
                                      I ordered a rebulit clutch (Murry brand) from E bay and which ever shows up 1st will go on. I also ordered a rebuilt drive plate, so if neither clutch looks good or arrives, I can fit my 6 3/4" pulley. it would slow the compressor a bit, but think that would only be an issue at idle.
                                      My take on line filters is this: If you have metal in the system, you need to get it out, I could see putting a filter ahead of the suction port, and may be the Tx valve if you had a bad failure, and cleaned (flushed) as best you can but want to be sure no crap ruins something else. A high pressure cut-off at the compressors would then be mandatory. Still, I think it would be making the best of a bod situation .
                                      I think I may have screwed up. When I rebuilt the system a year ago, and 1st started with the OEM condenser, I burst a high pressure hose (old OEM, hose) and expelled all the refrigerant along with a bunch of oil. I replace the hose and condenser, and made a best guess as to how much oil to add and went back with that. I had planned to check the oil after the system had run, but had other problems with the truck, and don't remember doing so. I checked it yesterday and found the level high, and drained back to the level plug. I suppose the extra oil could have caused start-up resistance leading to clutch problems. Live and learn, or at least teach myself to write down what I mean to get done so I don't forget. Hard to ruin a compressor with a little too much oil, I suppose you could hydro-lock if you had way too much, even then it would be the clutch that would take the worse beating.


                                        "Little too much oil"
                                        Did that on one of my own is a good thing, for another I'd be ticked and fix that. It worked till the frame fell off the car (way too common to play Fred Flintstone with rusted everything) but sloshed (had to be that) in the condenser still tube and fin converted was guessing but cooled fine just on a hard turn would go warmer for a bit then straighten out so no big deal it worked!

                                        MetroWest, Boston