Wobbly Water Pump Pulley - Problem?

[Stuart F.]

Last night I watched "Chasing Clasic Cars" on one of the Discovery Cable Channels. They were checking out an Auburn Boat Tail Speedster, and Wayne mentions while the engine was running that the water pump pulley was wobbling and concluded that it would probably be needing a water pump soon.

Today I changed my oil on my L-76 63 and while I was running the engine, I too noticed my water pump (double groove) pulley wobbles some as well. Does that mean I'm due for a pump failure soon. Guess I never noticed it before - it may be a new condition, or one that's been that way for a long time. Don't hear anything unusual.

Stu Fox

[Stephen L.]

Re: Wobbly Water Pump Pulley - Problem?

Check to see if you can move the shaft. Maybe the pulley is bent. If the shaft is loose, it'll start leaking from the weep hole..

[Domenic T.]

Re: Wobbly Water Pump Pulley - Problem?

Stu,
What Stephan said is correct. You may want to take the belt off and spin it by hand also and feel for roughness in the bearing.
Another thing is the was the flang was pressed on. A lot of the water pump pulleys wobble because the pump shaft was not standing straight when they pressed the flange on.

DOM

[Bruce B.]

Re: Wobbly Water Pump Pulley - Problem?

I rebuilt the waterpump on my 62 340 HP car about 15 years ago. It was very difficult pressing the parts off and back on the shaft but I got it done and after installation I noticed a small wobble at the pulley. Checked the pulley and it looked like the hub (flange) had the wobble.
20,000 miles later it still wobbles and does not leak.

[Stuart F.]

Re: Wobbly Water Pump Pulley - Problem?

Thanks for the input fellows. I'll be keeping a close eye on it now, and check it out with the belts off. Funny I'd never heard of a wobble being a possible indicator before.

Stu Fox

[Joe C.]

Re: Wobbly Water Pump Pulley - Problem?

Stu,
What Stephan said is correct. You may want to take the belt off and spin it by hand also and feel for roughness in the bearing.
Another thing is the was the flang was pressed on. A lot of the water pump pulleys wobble because the pump shaft was not standing straight when they pressed the flange on.

DOM

Exactly correct!! Ask me how I know this, because my pump shaft broke at 7200 RPM, which caused almost instantaneous boil over at the race track on a 95 degree day. Shaft snapped right at the weakest point, which is where the diameter is machined into an inner race for the ball bearings..............midway between the impeller and the pulley hub. Replaced bearing with a full needle bearing FAG unit which has a larger ID at the needle bearing inner race.

Sometimes the pulley itself can create an illusion of eccentricity, even though it is running true. This can be due to variations in the thickness of the outer circumference of the sheave walls. If the belt runs without side-to-side motion, but the pulley appears to be wobbling, then chances are that it is not.

[Joe R.]

Re: Wobbly Water Pump Pulley - Problem?

Stu,

The old saying, " an ounce of prevention is worth a pound of cure" applies here.

The water pump can cause great damage to the shroud AND the radiator.

Fixing a wobble is insurance against a disaster! Don't let this one slide!

JR

[Stuart F.]

Re: Wobbly Water Pump Pulley - Problem?

Thanks for the advice Joe. I'll check it out today. The fan clutch and fan itself seems to be running true, but it's still worth investigating. My records indicate I put a new pump on in 1992 along with a fan clutch, rebuilt the alternator a few years after that and changed to a new idler (the old one was singing).

Hope to see you at the winter meet next week. I have the plan of vendor spaces put out in the "Sticky" by Tyler Townsley, so I'll look you up.

Stu Fox

[Stuart F.]

Re: Wobbly Water Pump Pulley - Problem?

Joe C. Sorry for the mis-communication about the winter meet. I was responding to Joe Ray's comment, and I believe he will have a vendor booth there.

Thanks for relating your experience and advice. I appreciate it buddy.

Stu Fox

[John S.]

Re: Wobbly Water Pump Pulley - Problem?

FWIW I had a wobble in my water pump pulley that I noticed last year. At the time I indexed it around a few times and reset it. It was better but never right. Just finish putting Vintage air on the car and had to replace the pulley (and the balancer pulley) with two groove pulleys. Bought them from Vintage air and was surprised that they were actually GM pulleys. Started the car up today and I was simply amazed at how PERFECTLY true the water pump pulley ran. Saving all my old parts in case I ever take the air off, but I am putting a little note in with the pulley about the wobble!

[Edward J.]

Re: Wobbly Water Pump Pulley - Problem?

Stu, just to add a little insite check to make sure the mounting surfaces are clean and free from rust on the pump surface or pulley, or even to much paint on the pulley its self.

[Gerard F.]

Re: Wobbly Water Pump Pulley - Problem?

FWIW I had a wobble in my water pump pulley that I noticed last year. At the time I indexed it around a few times and reset it. It was better but never right. Just finish putting Vintage air on the car and had to replace the pulley (and the balancer pulley) with two groove pulleys. Bought them from Vintage air and was surprised that they were actually GM pulleys. Started the car up today and I was simply amazed at how PERFECTLY true the water pump pulley ran. Saving all my old parts in case I ever take the air off, but I am putting a little note in with the pulley about the wobble!

John,

I see you finally did it. Good for you.

Cheers,

[Stuart F.]

Re: Wobbly Water Pump Pulley - Problem?

Checked for any pump noise or play in the shaft, cleaned mounting surfaces of pulley on pump, etc. Everything looks alright. The distortion in the pulley is in both grooves for about 3 to 4 inches, just like a little swerve, but not enough to upset the belts noticeably. It has probably been that way a long time, and how it got that way I'll never know. Just wondered if anyone else had such an animal - 63, dual groove water pump pulley used on SHP engines.

Thanks for your insight/thoughts. I buttoned it back up and will just keep an eye on it.

Stu Fox

[James H.]

Re: Wobbly Water Pump Pulley - Problem?

I to have the wobble on my 67 BB, but only at idle is it noticable.rev it up and its gone. So does that mean its the pulley?
Jim

[Ruedi K.]

Re: Wobbly Water Pump Pulley - Problem?

Now I noticed a wobble on my 63 SB, too. Even though water pump is rebuilt. But the pulley on my car looks a bit worn out (>30years old)