65 shp water pump pulley wobble.

[Jim R.]

My deep groove water pump pulley seems to wobble at low idle ,then if you rev it a little it goes away, would this be a slight bend in the pulley or could it be the water pump, it has always done this .I just wonder if i should buy a new pulley.

[Gene M.]

Re: 65 shp water pump pulley wobble.

Jim,
Remove it and look close and see if you have a crack thru one or more of the mounting holes on the pulley.

This is a typical issue with old original parts as miles pile on.

[Timothy B.]

Re: 65 shp water pump pulley wobble.

Jim,

I am not sure about 1965 but for 67 there is a reinforcement that's used under the pulley to keep this from happening. My 1963 pulleys wobble like your 65..

[Gene M.]

Re: 65 shp water pump pulley wobble.

Tim, that is true there should be a cup washer to aid strength but many, many times it is missing causing the pulley to crack. If it is cracked welding/grinding or new pulley is in order.

[Joe L.]

Re: 65 shp water pump pulley wobble.

Tim, that is true there should be a cup washer to aid strength but many, many times it is missing causing the pulley to crack. If it is cracked welding/grinding or new pulley is in order.

Gene and Jim------


Some pullies have a welded-in reinforcment. This very easy to discern. Such pullies need no extra, external reinforcement. However, if the pulley doesn't have such a welded-in reinforcement, then the separate reinforcement, GM #3720616, MUST be used even if it was not originally used and even if adjusting the waterpump hub spacing must be done to accommodate pulley alignment.

[Joe C.]

Re: 65 shp water pump pulley wobble.

I don't believe nobody asked you whether or not you removed the belt and checked the pump bearing for wobble?????????

If your 426 pump needs to be rebuilt, be sure NOT to re-use your nice, original 4-hole pulley mount hub. Use a new billet steel hub.

[Joe L.]

Re: 65 shp water pump pulley wobble.

I don't believe nobody asked you whether or not you removed the belt and checked the pump bearing for wobble?????????

If your 426 pump needs to be rebuilt, be sure NOT to re-use your nice, original 4-hole pulley mount hub. Use a new billet steel hub.

Joe-----

He mentioned that the "wobble" appears to cease at higher RPM. I think the "wobble" would get worse at higher RPM if the waterpump bearing OR otherwise-caused waterpump flange runout were the problem.

[Paul J.]

Re: 65 shp water pump pulley wobble.

My deep groove water pump pulley seems to wobble at low idle ,then if you rev it a little it goes away, would this be a slight bend in the pulley or could it be the water pump, it has always done this .I just wonder if i should buy a new pulley.

Jim,

I think all of the advice about the pulley is correct, but there is a quick check that you should do to eliminate the bearings before you disassemble anything. Just listen. Failing bearings make a distinct swishing/grinding noise very audible at idle. If there is too much belt noise you can soap the belts (very slightly) to quiet them down. If you don't hear anything unusual then concentrate on the pulley, but I think that you'll end up there anyway.

Paul

P.S. This test usually does not work on 60s/70s Fords. The belt systems make too much noise.