Progress Thread Komo's 1990 GT - Parts Gathering Purgatory & Home Remodel
- Thread starter gkomo
- Start date
I noticed it jumping one time while squealing, but then the next few times it didn’t jump (that I could notice), but still squealed.
Earlier I mentioned some fixes. The most likely cause is the the tensioner or alternator is not parallel to the rest of the accessory drive.
The water pump mounting stud is what will makes the entire tensioner bracket parallel to the rest of the accessory drive. Be sure it is by installing it as I mentioned. For a shim you can use either washers, or possibly a thin jam nut if you have enough room. It needs to be perfect. Sand some washers for shims if need be. Brass washers sand easy.
When the tensioner is adjusted move on to the alternator.
^^When you install the alternator stay just do it finger tight and make sure both surfaces sit flush. It can't move the alternator at all when you tighten it. Watch very closly. If the alternator moves it will be pulled out of parallel and cause squeals.
Also you mentioned putting the alternator bolt in backwards. Are you sure it (or any of the other bolts) isn't hitting the block and keeping the main bracket from sitting flush?
Keep in mind there is a difference between a pulley being out of line and not being parallel to the rest of the accessory drive. There is some tolerance for pulley offset or "out of line" before you get squeals. There is almost no tolerance for a pulley that isn't parallel (crooked) before you get squeals
I had squeals. I fixed them by doing what I mentioned. .
I’ll go over all the things you mentioned just to double check. I mean I see what you’re saying about the pulleys being out of line compared to crooked. I don’t ‘think’ any pulleys are crooked but again I’ll check.
Just eyeballing the entire accessory drive while it’s idling they all look perfect I don’t see the belt bending or not being straight, all pulleys look to be right in line. Is there a reference point I can measure from or anything so I’m not just going off of my eye?
I’ll check any bolts hitting the block, but for sure the bolt I put in ‘backwards’ is not. All I had to do was trim like 1/8” off the forward end of that bolt because it would have interfered with the belt itself.
I mentioned above, I think I’ve pinpointed the squeal to the A/C pulley, but can’t be 100% sure since the engine running and all that noise makes it difficult to hear exactly. It only really squeals on startup and I’ve noticed the A/C engages even when the HVAC controls are are vent or floor when it’s on Heat (or so I see the compressor clutches moving in and out). So my thought process is the A/C is putting immediate load on the belt at startup? Not sure if my reasoning makes sense there though. Once the idle settles the squeal goes away.
Anyways, I’ll check my pulley alignments the best I can with a straight edge.
Do you think because I did witness the tensioner ‘jumping’ one time it’s starting to lose its effectiveness?
Well, you didn't have the squeal before you relocated the alternator and tensioner right? Logic would say the a/c compressor pulley was fine before it's probably fine now.
This is the water pump stud I'm referring to. In the picture the two bolts holding the tensioner to the s/c bracket are tight. The distance between the tensioner bracket and nut is what needs to be accurately shimmed.
When I was having these problems i started it up with the belt on and the tensioner attached as shown in my picture. My squeal was gone. Thats how i knew where the problem was. Then I carefully shimmed the gap and it's been fine since.
Use your own judgement on starting it like that. It seems sturdy enough for a test start to me.
This is the water pump stud I'm referring to. In the picture the two bolts holding the tensioner to the s/c bracket are tight. The distance between the tensioner bracket and nut is what needs to be accurately shimmed.
When I was having these problems i started it up with the belt on and the tensioner attached as shown in my picture. My squeal was gone. Thats how i knew where the problem was. Then I carefully shimmed the gap and it's been fine since.
Use your own judgement on starting it like that. It seems sturdy enough for a test start to me.
That's likely just fine, the belt has to turn all those pullies and they, the pullies, have to pump, suck or blow air or fluid at the same time so there is a 'aw
t we gotta get to work moment at start-up.
I think this is the same angle you have?
I think I have the same nut/washer spacer you do? (Top bolt sort of under the A/C bracket)
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Geezus, I think the belt I had on last night put too much strain on the power steering pump pulley, because when I went out to look at pulley alignment from under the car I saw a small amount of power steering fluid on the ground. It had never leaked before except for some wetness on the lines. Upon further analysis, the PS pulley has a small amount of play to it, like I can move the pulley forward/rearward just slightly and I see some fluid right inside where the pulley meets the pump. I screwed up!
As far as alignment goes I tried using my laser level, but it’s hard because the car is up on ramps so it’s not even with the laser from top to bottom or side to side. I took a straight edge from center of crank pulley to alternator and smog pump and from what I can tell it all looks aligned?
As far as alignment goes I tried using my laser level, but it’s hard because the car is up on ramps so it’s not even with the laser from top to bottom or side to side. I took a straight edge from center of crank pulley to alternator and smog pump and from what I can tell it all looks aligned?
Yeah. So what I suggest is to remove that nut and washer behind the tensioner. Then reinstall the tensioner. Just let that stud sit free in the tensioner hole temporarily. Don't put the front nut back on. Just tighten the two bolts that hold the tensioner assembly to the S/C bracket. See if it still squeals.
You really need to systematically go through this. Try what I mentioned and check back.
You could consider that attachment point on the water pump stud what adjusts the tensioner bracket and entire tensioner parallel to the accessory drive. It doesn't take much at all for it to be off and cause a squeal. Maybe it is, maybe it's not your issue. But until you check it you can't rule it out.
As far as the p/s pulley you can usually get some in and out play. But I feel you're chasing the wizard here with belt sizes and tighter tension. Something isn't properly aligned.
You really need to systematically go through this. Try what I mentioned and check back.
You could consider that attachment point on the water pump stud what adjusts the tensioner bracket and entire tensioner parallel to the accessory drive. It doesn't take much at all for it to be off and cause a squeal. Maybe it is, maybe it's not your issue. But until you check it you can't rule it out.
As far as the p/s pulley you can usually get some in and out play. But I feel you're chasing the wizard here with belt sizes and tighter tension. Something isn't properly aligned.
Alright I’ll keep at this, thanks for all the suggestions.
No problem.
It's hard to see in my picture. There is a small gap between the tensioner bracket and the nut. It's floating there and square. It won't squeal like that. The gap is about half as thick as a standard thin washer. It i put a nut on and tighter it down it will close that little gap, pull the tensioner in that small amount out of parallel and squeal like a stuck pig for about 1-1.5 seconds on startup. Particularly cold starts. It really doesn't take much.
It's hard to see in my picture. There is a small gap between the tensioner bracket and the nut. It's floating there and square. It won't squeal like that. The gap is about half as thick as a standard thin washer. It i put a nut on and tighter it down it will close that little gap, pull the tensioner in that small amount out of parallel and squeal like a stuck pig for about 1-1.5 seconds on startup. Particularly cold starts. It really doesn't take much.
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Good thread with the info here:
So there is a post on the back of the tensioner that positions it on the bracket it attached to. Make sure that post is locked into the correct hole so that the tensioner is correctly positioned and can actually create tension. If it is installed correctly then you need a new tensioner or a different length belt.
Bracket without tensioner installed:
Bracket with tensioner installed:
Bracket without tensioner installed:
Bracket with tensioner installed:
Alright, got the nut off @nicholase suggested. The bracket did ‘bend’ back forward a tad, to create a small gap between the bracket and rearward nut behind it. I can’t start the car now but will try tomorrow to see if it goes away.
@nicholase i know you suggested removing the washer and nut behind the bracket (so the bolt is bare), just curious as to why that’s necessary? If the Paxton tensioner bracket moves away from that nut then isn’t it fine leaving it?
Pending outcome of that answer, I got the 90.31” belt on, and the supercharger belt back on, ready to test fire her up.
On a side note, my panhard bar came in. I’m not so sure I’ll tackle that right away… getting a little project fatigued just where I’m at with this whole install at the moment.
@nicholase i know you suggested removing the washer and nut behind the bracket (so the bolt is bare), just curious as to why that’s necessary? If the Paxton tensioner bracket moves away from that nut then isn’t it fine leaving it?
Pending outcome of that answer, I got the 90.31” belt on, and the supercharger belt back on, ready to test fire her up.
On a side note, my panhard bar came in. I’m not so sure I’ll tackle that right away… getting a little project fatigued just where I’m at with this whole install at the moment.
The idea of removing the nut entirely is to make sure it's not influencing the tensioner bracket at all for your test start. If you loosened the outer nut and the tensioner mount pulled away it isn't. However if you loosened the outer nut and it didn't pull away you wouldn't be sure if the inner nut was holding the bracket out of parallel. That's why I suggested just to remove it.
The fact that the tensioner mount pulled away when you loosened the outer nut tells you that tightening the outer nut pulls the tensioner out of parallel. So that will need to be shimmed regardless of the results before you move on to the next step. Step by step, adjust things as you go and you'll get it.
However you do want to make sure the stud isn't binding in the bracket hole and holding it from returning fully back to it's natural position. As long as you loosened it all up and determined the tensioner was free on the waterpump stud then retightened the two bolts holding it to the SC bracket you should be good.
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The fact that the tensioner mount pulled away when you loosened the outer nut tells you that tightening the outer nut pulls the tensioner out of parallel. So that will need to be shimmed regardless of the results before you move on to the next step. Step by step, adjust things as you go and you'll get it.
However you do want to make sure the stud isn't binding in the bracket hole and holding it from returning fully back to it's natural position. As long as you loosened it all up and determined the tensioner was free on the waterpump stud then retightened the two bolts holding it to the SC bracket you should be good.
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Started the car up today to test if moving the tensioner to water pump stud bolt (and hence moving that end of the tensioner forward) would eliminate the belt squeal. It drastically improved the squeal, I now only get maybe a split second of belt squeal right at startup whereas before I would get anywhere from 5-10 seconds of squeal. I also blipped the throttle and didn’t get any squeal whereas before blipping the throttle would sometimes induce squeal. I’m wondering if it actually needs a thick shim to push it out even further? I’ve cut a washer with my dremel to have an open end to test this theory (just jam it in between the bracket and nut behind) just so I don’t have to remove the entire tensioner assembly and bracket. If it works then I’ll put a full washer on as a permanent solution.
Good. I figured that would help. Certainly play around with it and see if you can completely eliminate the squeal with small adjustments there.
I feel the problem with the tensioner relocation is that it doesn't mount to a single bracket like the factory one did. It mounts to a small plate that is attached to the new blower bracket (which mounts to heads and block) and also straddles over to the water pump stud. While that might have worked better with brand new factory fresh cars.... most aren't anymore. So small tolerance differences in replacement waterpumps, timing covers, aftermarket gaskets can all create what's know as "stacked tolerances ". Meaning many parts with slightly different tolerances from original can create a larger difference. Any tolerance difference with the water pump attachment point pulls it out of parallel.
If you can't completely eliminate the squeal with just the tensioner I steered you to I suggest leaving it float (for now) and move to the alternator.
This is a similar situation. Remember earlier when I suggested tightening just the long bolt that secures the alternator to the main bracket. Then carefully making sure the bottom L bracket doesn't pull it out of parallel when you snug it up? Same deal. That L bracket is like the water pump stud for the tensioner. A very small change can create or eliminate a squeal.
Loosen that L bracket and make sure it's not pulling the alternator out of parallel at all. Now you know how little it takes to make a nasty squeal.
Remember it's made for a factory alternator. You don't have one. You have a 130a alternator that is actually so large it required grinding your smog pump to fit. Chances are you will need a little loving there. You might need to bend the L bracket slightly, or elongate the holes. Small, small adjustments.
I really feel between these two things you'll completely eliminate it. Heck, you might clear it up with just the tensioner.
Good luck with it.
I feel the problem with the tensioner relocation is that it doesn't mount to a single bracket like the factory one did. It mounts to a small plate that is attached to the new blower bracket (which mounts to heads and block) and also straddles over to the water pump stud. While that might have worked better with brand new factory fresh cars.... most aren't anymore. So small tolerance differences in replacement waterpumps, timing covers, aftermarket gaskets can all create what's know as "stacked tolerances ". Meaning many parts with slightly different tolerances from original can create a larger difference. Any tolerance difference with the water pump attachment point pulls it out of parallel.
If you can't completely eliminate the squeal with just the tensioner I steered you to I suggest leaving it float (for now) and move to the alternator.
This is a similar situation. Remember earlier when I suggested tightening just the long bolt that secures the alternator to the main bracket. Then carefully making sure the bottom L bracket doesn't pull it out of parallel when you snug it up? Same deal. That L bracket is like the water pump stud for the tensioner. A very small change can create or eliminate a squeal.
Loosen that L bracket and make sure it's not pulling the alternator out of parallel at all. Now you know how little it takes to make a nasty squeal.
Remember it's made for a factory alternator. You don't have one. You have a 130a alternator that is actually so large it required grinding your smog pump to fit. Chances are you will need a little loving there. You might need to bend the L bracket slightly, or elongate the holes. Small, small adjustments.
I really feel between these two things you'll completely eliminate it. Heck, you might clear it up with just the tensioner.
Good luck with it.
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