Bornindesert Posted September 9, 2013 Share Posted September 9, 2013 88' 4.0 Auto with AC, stock Alt and new Pwr steering pump and Dayco belt. Truck has been back on the road for about a month. We've adjusted the belt tension numerous times, the squeak will go away or come and go intermittently. It's running true and straight and does change pitch when AC is on or off. It's adjusted correctly, tight but not too tight. By ear, the squeak seems to be coming from the water pump. It was replaced about 10 years ago, and was a reman. Could this erratic belt squeal be a bad water pump bearing? It's not leaking, runs at the proper temp, no cooling issues at all. I'm down to just replacing it if I can't figure out any other source of the squeaky belt, which may in fact not be the belt at all but the pump bearing. Link to comment Share on other sites More sharing options...
1989 Eliminator Posted September 9, 2013 Share Posted September 9, 2013 It is possible... I have a 89 and I just replaced my water pump because it was leaking. But I also only have 70xxx miles on it. make sure there is no rubber wear that is stuck to the pulleys. Sometimes for heat and everything else the belt wears off on the pulleys and squeaks because of that. Link to comment Share on other sites More sharing options...
sloride Posted September 9, 2013 Share Posted September 9, 2013 You might get an auto stethoscope and see if you can pin point the sound's origin that way. If you don't have one of those you might look in your tool box. I've used everything from an extra long screw driver to round bar stock to even a crow bar to hear where a squeak is coming from. Place one end on the suspect part and the other to your ear is all you do. Link to comment Share on other sites More sharing options...
Bornindesert Posted September 9, 2013 Author Share Posted September 9, 2013 Good idea, I'll try the long extension and see if it agrees with the bearing hypothesis. I did actually use one of those super long oil funnels with the small end at my ear...but you really can't get super close because of the fan. Link to comment Share on other sites More sharing options...
FrankTheDog Posted September 9, 2013 Share Posted September 9, 2013 You'll probably want to ditch the dayco belt and get a gates or goodyear belt. I just went through this on two jeeps, both being the belt. #1 was a 1 year old dayco belt and I tried everything to get the squek to stop. Seeing how I was just putting the jeep on the road I changed out the bearings in the pulleys and put a new water pump on. Still squeeked. Ended up putting a new Goodyear belt on. #2 had a 1 year old Goodyear on and a 1 year old water pump. Changed the idler pulley out because I had one and did the stethoscope trick, no change no bad bearings.. Tried tightening the belt and it got worse. Ended up loosening the belt until the squeel went away. That was yesterday and I haven't drivin in the rain yet so we'll see if it cures it. Try a good quality belt, that's the only way I've been able to stop the squeek. Link to comment Share on other sites More sharing options...
Incommando Posted September 9, 2013 Share Posted September 9, 2013 Comet cleaner on the belt works wonders for stopping squeals :thumbsup: Link to comment Share on other sites More sharing options...
Bornindesert Posted September 10, 2013 Author Share Posted September 10, 2013 So before I tear into the pump I think I'll try swapping out the belt with the old one or one that I know doesn't squeal. Thanks for sharing your experience with the Dayco belt. Sure looks like a decent belt! Just no manners. Link to comment Share on other sites More sharing options...
Exgrayxj Posted September 10, 2013 Share Posted September 10, 2013 While you have the belt off give the alternator a couple spins ... it is possible you have an alt bearing going bad. I sometimes rub some bar soap on the belts at idle, it stops things for a while. Link to comment Share on other sites More sharing options...
Bornindesert Posted September 10, 2013 Author Share Posted September 10, 2013 Will definitely give the alternator a twirl once the belt is off. Now that I thinking about it I'm going to try and determine if the squeak is once per belt revolution or higher. If it's once per belt revolution I'd lean toward the belt. If its random or not in sync, might be a pulley or accessory Link to comment Share on other sites More sharing options...
Oyaji Posted September 10, 2013 Share Posted September 10, 2013 One fella mentioned Comet scouring powder, another soap, but the best product is belt dressing - just spray it on the grip side of the belt while the engine is running. . With regard to bearings. while you have the belt off you may as well check every driven pulley (including idler) for high drag. Regarding belt tension, it wouldn't hurt to double-check tension measurement after running the engine (to ensure that tension is distributed along the whole length of the belt). I know that as long as there is no slippage, minimal belt tension extends bearing and belt life, but I've been surprised at how much tension it takes to stop a serpentine belt from slipping and squealing. Link to comment Share on other sites More sharing options...
87MJTIM Posted September 10, 2013 Share Posted September 10, 2013 I had a terrible squeal with mine for a long time. Replaced the belt several time and the water pump, but did not fix the squeal. Turns out it was the harmonic balancer. Now, no squeal. $0.02 Link to comment Share on other sites More sharing options...
Bornindesert Posted October 3, 2013 Author Share Posted October 3, 2013 Update - tried most if not all of the suggestions and still has a squeak. All the pulleys are spinning freely and have no bearing play, replaced the Alternater (more of an upgrade to 100A), switched out to a known good AC Delco Belt, belt dressing, various tensions and no improvement. If you squirt some WD40 it immediately goes silent for about 30 seconds and then comes back. Once the engine comes up to full operating temperature, the squeak sometimes goes away or dies down. It gets louder if you rev the engine. The belt is not exactly tracking to the center of the Fan pulley, which means that coming off the Alternator and entering the Harmonic balancer pully the belt runs toward the back of the Fan pulley, has about 1/8 inch gap from the front lip. There is no adjustment for the Fan pulley, it is part of the A/C motor mount. Just to verify cpa tim...mine is not a continuous squeal, it's a squeak that chirps every belt revolution and it's fairly load. That said, wondering if yours was a continuous squeal or repeating chirp? The noise seems to be coming from between the water pump pulley and the harmonic balancer, so it's possible that could be the cause of the belt squeak. So, I'm now thinking...could it be the Harmonic balancer? Link to comment Share on other sites More sharing options...
87MJTIM Posted October 3, 2013 Share Posted October 3, 2013 It did "chirp" It was pretty consistant, though. Sometimes it would not be chirping then suddenly it would start. Link to comment Share on other sites More sharing options...
FrankTheDog Posted October 4, 2013 Share Posted October 4, 2013 I have the same problem, I picked up a harmonic balancer today to see if that'll fix it. I'll let you know in a few days or so. Depends when I have time to get to it. Link to comment Share on other sites More sharing options...
Bornindesert Posted October 4, 2013 Author Share Posted October 4, 2013 I have the same problem, I picked up a harmonic balancer today to see if that'll fix it. I'll let you know in a few days or so. Depends when I have time to get to it. Sounds good, I may swap the balancer off another motor I have and will also post up any improvement. Are you thinking that it can be swapped out without removing the radiator? It did "chirp" It was pretty consistant, though. Sometimes it would not be chirping then suddenly it would start. Thanks - we are off to the harmonic balancer races! Really looking to get this one thing taken care of, my son understandably does not like taking his Comanche out in public with such an obnoxious belt squeak. Link to comment Share on other sites More sharing options...
Bornindesert Posted October 20, 2013 Author Share Posted October 20, 2013 Update: swapped out the harmonic balancer and the squeak is gone! Engine is running nice and quiet, smooth and steady idle. Never would have guessed bad harmonic balancer. Thanks for the lead. Link to comment Share on other sites More sharing options...
87MJTIM Posted October 20, 2013 Share Posted October 20, 2013 Good to hear. Link to comment Share on other sites More sharing options...
zackcj7 Posted October 21, 2013 Share Posted October 21, 2013 Update: swapped out the harmonic balancer and the squeak is gone! Engine is running nice and quiet, smooth and steady idle. Never would have guessed bad harmonic balancer. Thanks for the lead. Any tips on the harmonic balancer replacement? Did you replace the seal as well? I need to do mine soon. Link to comment Share on other sites More sharing options...
Bornindesert Posted October 21, 2013 Author Share Posted October 21, 2013 Update: swapped out the harmonic balancer and the squeak is gone! Engine is running nice and quiet, smooth and steady idle. Never would have guessed bad harmonic balancer. Thanks for the lead. Any tips on the harmonic balancer replacement? Did you replace the seal as well? I need to do mine soon. Did not replace the seal, and I think that would make a difference in how you approach the balancer replacement. Contrary to the AMC repair manual, you do not need to remove the radiator. I did remove the cross brace above the radiator, so I could remove the fan shroud and the electric fan was also removed. Belt was of course taken off before starting on the balancer. Left the mechanical fan on it's pulley. We worked from the top, and bottom to chase the 5/16" NC balancer threads with a tap. You'll likely need to run (2) hardened grade 8 bolts in to restrain the crank from rotating while you get a 3/4" socket on the crank bolt. It broke free fairly easy, two man job...one holding a prybar and the other on the breaker bar. I went a bought a crank puller, it was like $17 at Autozone...BUT, after it was all said and done I probably could've used the steering wheel puller I had in the tool box. If you have one of those, check it out. Since you'll be discarding the old balance, guess you could try any old puller but I'm a right tool for the job kind of guy. Once you get the crank bolt out, set up the balancer puller and wrench it with a 3/4" open end from the bottom. The wrenching end of the puller will be right up into and above the lip of the lower chassis frame. Tight but doable. Balancer should walk right out. The bad one was shot, the rubber was crooked and the inner / outer segments has started drifing apart. Link to comment Share on other sites More sharing options...
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