Waterpump pulley works loose

[adriantr4]

Hello

 

My standard waterpump pulley (#105537) has destroyed itself, and the waterpump shaft by somehow working loose. The securing nut had not moved though? The pulley has a groove to accommodate the Woodruff key, but this groove and (alas) the corresponding groove in the pump shaft has massively distorted, causing the pulley to gyrate on the shaft. Or perhaps the other way round?

 

Anyone else experienced this, any solutions?

 

I've pretty much copied & pasted the above from my "wanted" ad in the TRade section, so apologies for some duplication.

[Smokey]

Was the Woodruff key the correct size? It should be a tight fit in both the shaft and the pulley.

[ians]

Does the water pump turn? Is it seized?

 

Under normal circumstances the woodruf key (proper size and fit) should easily take the water pump loading. So either the pump has seized or the key was incorrectly sized/fitted!

Edited July 5, 2010 by ians

[Rod]

Hi Adrian

 

My pump packed up on the 4A last weekend. Turned out the shaft broke near the thread for the lock nut. Somehow the impeller was turned by friction so no overheating, but a lot of swarf under the bonnet. The pulley and key were not salvagable but a new pump and pulley from TRGB is about £65 plus postage and packing ( I collected mine ) so repair was rapidly effected. They have several in stock. Put a new belt on for good measure.

 

Regards

 

Rod

[adriantr4]

Hello

 

Thanks for the replies.

 

Yes, the Woodruff key was the correct one & the pump bearings are fine. It all fitted together ok - or so I thought?

 

I think the problem was with my pulley, and has been building up for years as I've had minor pump & pulley problems in the past. I think the pulley somehow did wear on the pump shaft (several pumps ago) and has been building up ever since. I seem to recall swapping out pump/pulley bits with a club member aeons ago when I need to get fixed fast, yeah maybe that was it ....

 

No-one else experienced a gyrating pulley, but the holding nut still ok?

[Smokey]

If one mating part is worn, it will quickly wear out the other one(s), for instance wire wheels and splined hubs. (Ask me how I know.) So it there is any doubt, replace all the mating parts at the same time. I suspect if you replace the pump, key and pulley your problem will be solved.

[RogerH]

Hi Adrian,

I wasn't going to reply but when you mentioned 'gyrating' well I just had to.

My recently purchased 4 experienced the pulley coming adrift within 5 miles from where I purchased the car (retaining washer too small!!)

Quick fix. When I got home I noticed the pulley doing a figure of 8 dance around the pump.

Pump & pulley will need replacing.

 

Roger

[adriantr4]

Hello again.

 

My thanks to all replies, and a special mention to Alec Pringle for helpfulness above & beyond the call of duty. Everything is fixed.

 

Here is what I've learned, once you have the pump proper & pulley on the bench: The slot for the woodruff key in the pulley should be a nice straight groove to locate it. If it isnt then eventually the pulley will slop about on the pump shaft. In my case this became severe and wore away the shaft, causing the pulley to gyrate & ultimately collide with the pump body.

 

[When it started to wear I could only just hear something on acceleration, so I thought "pinking" and retarded the ignition. And kept retarding it. Then it wasnt running right & the plugs fouled, then I weakened the mixtures .... there have been other separate ignition issues too, but you get the picture.]