Water Pump Pulley Wobble

[Blackie]

Hi All,

I had an alternator belt let go tonight, and have since noticed that when i spin the water pump pully, it seems to not be spinning straight, seems as though the pully has started to back off the shaft unvenly. The roadside assistance fella reckons this is what made the belt spit.

The water pump is brand new as of 2010, only has 10K miles on it, so i would hope it isnt an internal issue, there is absolutely no play in the shaft, and the pulley seems to be on real tight too.

Is there a way to re-seat the pulley without removing the whole pump from the car? Also, is the pulley backing off the shaft a common issue, or could it be posible that the shaft has somehow bent?

Thanks in advance!

[Chris 16409]

This is one of the reasons I got a bolt on pulley. Did your pulley come new with the pump, or did you reuse it? Once you press a pulley on the first time, it will never be as tight a fit if it's being pressed on a second time.

[Blackie]

This is one of the reasons I got a bolt on pulley. Did your pulley come new with the pump, or did you reuse it? Once you press a pulley on the first time, it will never be as tight a fit if it's being pressed on a second time.

Hi chris,

I am not sure if the pulley was re-used when the pump was replaced, the job was done in the US before the car was imported. Having said this it doesnt look too old.

Cheers

[Rich]

Am not aware of Water Pump pulleys coming loose as a particular problem with D's.

You may want to look at all possible causes of losing the belt. Pulley runout might be it, as your assistance fella suggested. Other causes to look into would be

- alignment of all of the pulleys: use a straightedge to see that each pair of the 3 pulleys under that belt are in the same plane, neglecting the wobble of the WP pulley for the moment. Sometimes an owner will install an alternator that isn't a direct fit re the pulley.
- belt age: was it new when the WP was renewed 10K miles ago?
- belt tension: you won't be able to tell directly now that it's broken but you could look at the old belt for signs of glazing on the contact surfaces. Low belt tension -> slippage/overheating/glazing -> premature breakage

Given that you breakage occurred in the Ozzie summer that last one might be interesting...

There's no reason not to try to straighten the WP pulley so long as your method doesn't kill the bearings.

[jawn101]

Clint (vwdmc16) had his pressed-on WP pulley back off completely at one time. I forgot his warnings when I ordered my new pump and got one with a pressed-on pulley as well, as opposed to a bolt-on one. He wouldn't even help me install it until I let him weld the pulley to the shaft.

[DMCMW Dave]

Pressed-on is fine as long as it's a NEW pulley or a straight used one that has been sleeved.

Typically the OEM pulley can be used over one time without problems, but since (after 30 years) it's pretty hard to know the history of a particular pulley, you need to be cautious.

[kings1527]

Blackie, were you able to find out what caused the wobble? My WP is wobbling right now and it was recommended that I get it replaced, which I agree. Did you end up fixing the WP or replacing it?

[jawn101]

Blackie, were you able to find out what caused the wobble? My WP is wobbling right now and it was recommended that I get it replaced, which I agree. Did you end up fixing the WP or replacing it?

Whether you fix or replace, you're removing it - and I bet once you pull the back off you'll find the wheel is rusty and gross anyway. Just replace it and let the vendor handle the rebuild.

[kings1527]

Whether you fix or replace, you're removing it - and I bet once you pull the back off you'll find the wheel is rusty and gross anyway. Just replace it and let the vendor handle the rebuild.

Copy that, will do. Thanks Jon!

[Ryan King]

I had a pulley back off of my Special T Auto pump. I got a bolt on pulley after that and have never looked back.