56 Buick Posted January 20, 2022 Share Posted January 20, 2022 Maybe I just never noticed it before but the fan pulley has a wobble as it turns. I am sure this would be no good for the water pump bearings. I took the fan and pulley off and it appears the water pump runs true and so the culprit seems to be the pulley itself, although I could be wrong. Is this a common problem? I am not sure what a best fix would be but at the moment placing some electrical tape strategically on the rear face of the pulley has removed a lot of the wobble. Any views or suggestions appreciated. Thanks Link to comment Share on other sites More sharing options...
Smartin Posted January 20, 2022 Share Posted January 20, 2022 Does the water pump shaft have any play in it? Like, can you wiggle it side to side? The only way the pulley will wobble is if it's bent, or the water pump bearing is toast. 1 Link to comment Share on other sites More sharing options...
56 Buick Posted January 20, 2022 Author Share Posted January 20, 2022 No sideways play that I saw but I will check again. Hard to see how the pulley could become bent as it's relatively substantial but anything is possible I guess. Link to comment Share on other sites More sharing options...
DCCD Posted January 21, 2022 Share Posted January 21, 2022 On 1/20/2022 at 7:31 AM, 56 Buick said: No sideways play that I saw but I will check again. Hard to see how the pulley could become bent as it's relatively substantial but anything is possible I guess. Is the water pump a new rebuilt? I got a rebuilt on my 364 and if I lightly tug on the fan with a finger, it rocks back and forth a little. 1 Link to comment Share on other sites More sharing options...
Smartin Posted January 21, 2022 Share Posted January 21, 2022 It definitely makes a difference if you can use the fan to rock the pump shaft. It magnifies the movement that may not be detectable without the fan installed. Link to comment Share on other sites More sharing options...
DCCD Posted January 21, 2022 Share Posted January 21, 2022 2 minutes ago, Smartin said: It definitely makes a difference if you can use the fan to rock the pump shaft. It magnifies the movement that may not be detectable without the fan installed. Not to go a different way with this thread, but would a slight wobble like I described be “normal”? Link to comment Share on other sites More sharing options...
Smartin Posted January 21, 2022 Share Posted January 21, 2022 There should be no lateral movement in the water pump shaft. 2 Link to comment Share on other sites More sharing options...
Pete Phillips Posted January 22, 2022 Share Posted January 22, 2022 I had a '56 Buick Special once, and it had a noise in the water pump--sounded just like a bad bearing. So, I bought a new one (back when you could still order a water pump for a '56 Buick from the local NAPA store, mid-1990s). Installed the new (remanufactured) pump and the noise was still there. Got the parts store to order another pump. Installed it--same bearing noise. At this point, the parts store said "no more '56 Buick water pumps". As I was reinstalling that one, I noticed a hairline crack in the fan pulley--all the way from the center of the pulley to the outer rim! Turns out, that was the "bearing noise". I found another fan pulley, and that got rid of the "bearing noise". It was a cracked pulley all along! Moral of the story: Carefully inspect your fan pulley. Does it sit flat on a flat surface? Does it have damage or a crack? Pete Phillips, BCA #7338 Leonard, TX. 3 3 Link to comment Share on other sites More sharing options...
56 Buick Posted January 22, 2022 Author Share Posted January 22, 2022 Thanks everyone. DCCD, I have a slight lateral movement if I pull on the fan also but I do note I cannot see that movement shown when the engine is running, or in other words I cannot see any detrimental effect from that lateral movement like the fan/pulley floating back and forth. Pete, no cracks or similar in the pulley but it is certainly difficult to find a dead flat surface with which to check the pulley. Even then it comes down to the pulley centre and the rim being completely parallel with each other, otherwise you will get that slight wobble. Using the electrical tape in just the right spot has pretty well removed the wobble. I used just 2 thin pieces so it is easy to see that it doesn't take much to put things out of true. I have been trying to think how best I could true up the pulley permanently but so far I am at a loss with the tools I have at hand. But perhaps the easiest way would be to take some metal away from the face of the boss of the pump that effectively compensates for the electrical tape I have used. Link to comment Share on other sites More sharing options...
Smartin Posted January 22, 2022 Share Posted January 22, 2022 What baffles me is that you are able to calm the wobble down by adding weight. There shouldn't be that much if an imbalance in the pulley to make a difference. Is it possible to find another pulley to confirm this is the problem? Or is there a big wad of dirt/garbage inside the pulley that is causing such an imbalance? Link to comment Share on other sites More sharing options...
56 Buick Posted January 23, 2022 Author Share Posted January 23, 2022 The pulley is clean but the tape I used was placed between the flat boss of the pulley and the boss at the end of the water pump shaft. In other words, the tape is between the 2 faces that bolt together. There is negligible weight as it is just 2 pieces of electrical tape about 1/2" square (one on top of the other) and the tape is at the centre of the spinning pulley. Sorry, re-reading my earlier text I did not make that clear. The tape is giving very slight height at a certain spot between the 2 mating surfaces. Seems this compensates for what I can only presume is a slight misalignment (at a certain area only) between the boss of the pulley and the line of the pulley v belt groove. Unless the line of the v belt groove is constantly parallel with the face of the boss of the pulley then there is potential for wobble. Maybe it was knocked at some stage causing the misalignment. I am just not sure how I could ever properly realign what is out alignment. I placed the tape where I did only after hand spinning the pulley by hand to see where the line of the v belt diverged but I cannot see any actual damage on the pulley. Anyway it seems to have worked for now. Link to comment Share on other sites More sharing options...
Smartin Posted January 23, 2022 Share Posted January 23, 2022 Ahhhh....now it makes sense. Yeah, it's bent🤣 1 Link to comment Share on other sites More sharing options...
56 Buick Posted January 23, 2022 Author Share Posted January 23, 2022 Any way to accurately correct the bend? Link to comment Share on other sites More sharing options...
avgwarhawk Posted January 23, 2022 Share Posted January 23, 2022 Large hammer, a square and a prayer. 1 1 Link to comment Share on other sites More sharing options...
56 Buick Posted January 23, 2022 Author Share Posted January 23, 2022 I think you are right on the prayer! 1 Link to comment Share on other sites More sharing options...
KAD36 Posted January 23, 2022 Share Posted January 23, 2022 Think it would be doable but dicey to tap on the flat part of the pulley and try to square it up Might end up chasing that “compensation” around the pulley - great way to spend an afternoon - ask me how I know. Have to keep its position syc’d up to the shaft so you’d know which area to raise and lower. Is the flange of the water pump true - all bolts equally torqued and have equally drawn the pulley onto the shaft? How snug is the fit of the pulley onto the end nub of the shaft? Maybe I missed that. Perhaps a thin piece of aluminum would hold up if the tape didn’t? In the meantime, thank you for sharing your successful hack to true up a slightly “off” pulley. Duly noted in the margin of my shop manual. With my #2 yellow pencil. 😎 1 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted January 23, 2022 Share Posted January 23, 2022 If you have a piece of steel large enough for the back side of the pulley you could lay the pulley on it face down and shine a strong flashlight perpendicular to the pulley to make sure no light gets through the edge and the steel. Same when flipped over on the front of the pulley. If no light on either edge the problem may lay with the boss on thecwater pump. A caliper may show extra thickness there but probably not a bent unit. At any rate it would seem one needs to be sure which of the three surfaces is not true before attempting any corrections. 2 1 Link to comment Share on other sites More sharing options...
Kosage Chavis Posted January 24, 2022 Share Posted January 24, 2022 Couldn't you use a dial indicator with magnetic base on the pulley? Just turn the pulley incrementally and tap the off balance side(s) till it is shows true on the dial. 1 2 Link to comment Share on other sites More sharing options...
56 Buick Posted January 24, 2022 Author Share Posted January 24, 2022 (edited) Actually these are all interesting ideas. I expect they or a combination of them would work. However I do suspect, as KAD36 indicated, I will spend a good 'afternoon' getting it right. Thanks everyone. Edited January 24, 2022 by 56 Buick Spelling (see edit history) Link to comment Share on other sites More sharing options...
EmTee Posted January 24, 2022 Share Posted January 24, 2022 Is it possible the pulley was 'tweaked' by someone using it as leverage for a pry bar while tightening the V-belt? I would try setting the pulley flat on the bench and placing a spirit level, or better yet an angle finder, on the mounting flange. Note the reading, then rotate the pulley 90* and repeat three more times. If it's actually bent, then you'll need to try to carefully try to true it up without distorting the groove. 1 Link to comment Share on other sites More sharing options...
KAD36 Posted January 24, 2022 Share Posted January 24, 2022 2 hours ago, EmTee said: without distorting the groove. Agree …that can be one of the trickiest parts…..which is off, the width of the groove, the mounting surface of the pulley, or the “parallelness” of the base of the pulley around its circumference to the mounting surface of the pulley. It can be like squeezing a balloon. 🤣 1 Link to comment Share on other sites More sharing options...
Bhigdog Posted January 28, 2022 Share Posted January 28, 2022 Twer it me I would bolt the pulley to the center of a lathe face plate or with an adapter in a chuck. Spin the lathe by hand while indicating the pulley to find the high spots. A few minutes with a piece of hard wood and a hammer is all it would take.........Bob 3 2 Link to comment Share on other sites More sharing options...
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