Nutty question

[onenyala]

I am in the process of fitting a Polyvee belt sytem on my Beta BZ482 to replace the original Vee belt.
I have to fit new pulleys to the engine cooling pump, the crankshaft end and the alternator.
It seems to be a relatively simple job. I have fitted the new pulleys to the crankshaft and the cooling pump but I am unable to release the nut which secures the pulley to the alternator.
The alternator is off the boat and I have been able to hold the pulley in a vice. Despite using my not inconsiderable weight and also gently heating the nut it just wont budge.
Unfortunately the nut is recessed into the pulley so it cannot be cracked or sawn off.
The engine is new (2years) so it is not a case of corrosion.
Any suggestions out there.

 

[fireball]

Does it undo the wrong way?

 

[holly1]

left hand thread possibly

 

[lenseman]

Well, my first suggestion is if you cannot see how to do it, then you really shouldn't be attempting it in the first place /forums/images/graemlins/grin.gif

BUT, if you have the pulley in a vice and it is securely clamped, apply liberal quantities of WD40 or penetrating oil and go for a cup of tea or coffee /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

When you come back, use a small 1oz hammer (a small hammer) and gently tap, tap, tap vertically down onto the top of the head of the nut or bolt. I usually tap about 30 - 40 times and then keep adding more oil. Don't hit too hard that you flatten or deform the head.

If it is a recessed nut , you might need a drift or even a small ½-drive by 4" socket extension bar with a smaller socket fitted such that you are hitting the annulus of the nut. These are GENTLE taps and it helps to free the tight threads and allows the oil to seep inside the helixes.

*** Now, if you are then able to move the nut or bolt, even ever so slightly, DO NOT try to undo straight away as you might shear or strip the thread of the bolt before it is fully removed. Use a 'T'-bar and socket and gently loosen and tighten then loosen and re-tighten the nut or bolt and at the same time apply more lubricating oil.

This should then become easier to turn and you should then be able to slowly remove more and more if the bolt. If you feel resistance as you start to undo the bolt, then you need to return to the back and forwards method with more oil until it becomes easier. DO NOT SHEAR THE BOLT !! /forums/images/graemlins/shocked.gif /forums/images/graemlins/smile.gif

As others have stated, it might be left hand thread?

Good luck

 

[PBooth]

Hi, try using an air impact gun, forwards and backwards, should do it. Also use it to fit the new pulley ( holding it in a vice might distort it). A local garage should be happy to do it for you if you don't have a gun of your own.

Peter

 

[DavidMcMullan]

I had this problem also and the air-impact gun sorted it. Most car service places have them and its a 2-minute job. Cost me a bag of doughnuts.

 

[macd]

Can't specifically help with the aggro you posted about, except to say that you won't be sorry you fitted a polyvee belt. Vee belts have no place on a 21st century engine.

I'm not familiar with your engine, but consider the direction of belt rotation. If it would tend to undo a right-handed fastener, then it may very well be (and arguably should be) a left-hand thread. They're always a right bu**er to undo the wrong way.

 

[lenseman]

[ QUOTE ]
They're always a right bu**er to undo the wrong way.

[/ QUOTE ]

Funny that, I always seem to strip the thread when I undo them the wrong way!! /forums/images/graemlins/confused.gif

 

[macd]

Yes, and ain't that just a bu**er?

 

[VicS]

[ QUOTE ]
it might be left hand thread

[/ QUOTE ] If the direction of rotation is counterclockwise

 

[onenyala]

Direction of rotation is clockwise. I tried the clockwise loosening route as well but no success. I'll try the local garage and see if they can get it off with an air gun.
Anyway thanks for all the suggestions.