Pulley alignment

[v-mad]

My tiger just trashed a fan belt. Looking at the water pump pulley, it is too far forward by about 1/4 inch. The dynamo pulley seems to be in line with the crank pulley, but behind the water pump. The water pump is alloy, so I wondered if it is a non-original replacement one that is not the correct type for the 260 engine?

[Chuck & Ollie Ingram]

by any chance did you replace the water pump lately?If so It may not have the pulley pressed on far enough.

[Tom and Joanne Ehrhart]

It’s probably a replacement pump which is fine. But most (actually all) replacement pumps do not have the hub position correct for the Tiger.
The fix is to remove the pump. support the back of the water pump shaft (NOT THE PUMP IMPELLER) and press the pulley on to its correct position. You know the Carpenter’s adage. Measure twice, cut once. Be sure to measure all clearance before taking pump off car so you know how far to press hub.

[v-mad]

OK, thanks for the tip guys, I will look into that. I would expect if a pump or any other part was bought from a Sunbeam supplier they would ensure it is correctly aligned? But I guess if any part it comes from elsewhere, like ebay, you just cant take anything for granted.

[v-mad]

I don’t have a WSM to refer to at the moment. To remove the pump, can this be done with engine and oil pan in-situ, as it looks like breaking the seal to the oil pan, which could be tricky without breaking the gasket? What do you recommend?

[v6-jose]

Hi Chris,

The water pump will come off without having to remove the front timing cover, which is what joins the oil pan by means of the pan gasket.

Jose 😀

[v-mad]

Thanks Jose. You are right of course, it is similar to most other engines where I have replaced the water pump. I think I panicked a bit thinking it would be a difficult job. I would bet though that the pulley mount will not move on the shaft because it is not a new pump, and has probably frozen, but I have to give it a try. I must consider investing in a proper press tool, as last time I broke my vice trying to press a bush out of the Alpine suspension 🙁
Cheers

[v6-jose]

Chris,

I would take it to a shop that has a press, so you can do it easily without putting pressure on the impeller, which would deform it. Also, I think it would be easier to move it the desired amount and not too far. The hub is pressed on to the shaft already, so you don’t have to worry that it has frozen in place.

Jose 🙂

[Bud & Donna Elliott]

I remember doing this job 25 years ago using a hammer and deep socket. It worked. Kinda.

[v-mad]

Success. I have now managed to shift it into the correct position. 😀 A bit of heat always works wonders with this kind of assembly. I applied the ‘persuasion’ only to the shaft at the centre of the impeller, not onto the impeller itself, which could cause it to crack (as it will be made of cast iron).

[cleandan]

I hope the “bit of heat” was not enough to damage the seal. This is VERY easy to do. If you got ANY portion of the shaft, hub, impeller, hot enough to glow or discolor you most likely ruined the seal too. Check it out before going to all the trouble of mounting and running a possible bad water pump. I wish you well.

[v-mad]

quote cleandan:

I hope the “bit of heat” was not enough to damage the seal……..

I hope so too! I heated only the flange, very carefully for a short time so that the shaft didnt get hot, and the flange alone would heat up and expand. All the time I was aware of the risk of seal damage, so I hope I got it right. I guess I would call it a calculated risk.

[v-mad]

I just came across the specification for the dimension between mounting faces. The WSM says it should be 13 cm. I just checked my pump, and it already measured 13cm before I adjusted it (is now 12.7cm and cant go any smaller as its touching the seal). So if the WSM is correct, something is wrong with my pulley set up!

OK, so I have improved the alignment between the pulleys on the crank and water pump, and it should work OK, but I havent really found the root of the problem.

Any further thoughts?

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