Alternator Fan, Pulleys & Shims
07-31-2006, 01:37 PM
#1
Three Wheelin'
Thread Starter
Alternator Fan, Pulleys & Shims
If anybody has any good pictures of the alternator fan & pulley assembly order I would appreciate it. There is alot of spacers and shims, and I'm not entirely sure where they all go. (Everything from the fan to the lock nut on the outer pulley)
In particular, I am not sure if any of those thin spacers are used between the pulley halves or not. It would seem to me if they are there should be a set number to give the pulleys a standard width.
(Proof that you can never take enough pictures when taking things apart!)
Kirk
In particular, I am not sure if any of those thin spacers are used between the pulley halves or not. It would seem to me if they are there should be a set number to give the pulleys a standard width.
(Proof that you can never take enough pictures when taking things apart!)
Kirk
07-31-2006, 02:56 PM
#2
Rennlist Member
I don't have pics but the shims are used to adjust the belt tension. You move them inside the pulley halves to decrease tension and outside to decrease.
The tension on these belts is important because of the length of the alternator shaft. There is a lot of leverage on the end of that thing! If they are too tight you will have a premature failure of the rear alt bearing.
You can get a belt tension guage for about $12USD around here at most auto parts stores. I can look up the tension stats if you need them.
The tension on these belts is important because of the length of the alternator shaft. There is a lot of leverage on the end of that thing! If they are too tight you will have a premature failure of the rear alt bearing.
You can get a belt tension guage for about $12USD around here at most auto parts stores. I can look up the tension stats if you need them.
07-31-2006, 03:03 PM
#3
Burning Brakes
fyi i just took mine apart and there was 1 shim between the pulley halfs and 3 outside the pulley. also, i thought the belt was too tight.
07-31-2006, 03:05 PM
#4
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Mark is correct. The shims are used to tension the belt.
Specifically, the order from inside out is:
1) Inside pulley half (already attached to the shaft)
2) one or more shims
3) outside pulley half
4) the rest of the shims (you're just storing them here)
5) the large thick washer (cupped side faces in)
6) nut
Start with half the shims inside the pulley and half out. Tighten it all up (lightly), turn the crank a few times to get everything settled in, and check the belt tension. If it's too loose, move shims from inside to outside. If it's too tight, do the reverse. Repeat until you have the correct tension, then torque to spec.
Specifically, the order from inside out is:
1) Inside pulley half (already attached to the shaft)
2) one or more shims
3) outside pulley half
4) the rest of the shims (you're just storing them here)
5) the large thick washer (cupped side faces in)
6) nut
Start with half the shims inside the pulley and half out. Tighten it all up (lightly), turn the crank a few times to get everything settled in, and check the belt tension. If it's too loose, move shims from inside to outside. If it's too tight, do the reverse. Repeat until you have the correct tension, then torque to spec.
07-31-2006, 03:07 PM
#5
Burgled
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The shims are also different thickness so you can fine tune the adjustment. Usually when I replace a new belt I have all the shims inside the pully halves and as the belt stretches I move one out in front of the pully. Seems to work for me. I seem to remember reading something in Adrians book about how many shims and sizes for each half but could be mistaken.
07-31-2006, 05:43 PM
#7
Three Wheelin'
Thread Starter
Aah I think I get it:
No spacers between pulley halves is the tightest setting, then you add spacers to make the pulley wider, and allow the belt to sit deeper in the groove and loosen the belt off.
So when you put a new belt in, put all but one of the spacers in to begin with, let it settle in, check your belt tension, and remove the spacers as required until the belt is tight. Repeat for belt #2.
Sound about right?
Kirk
Kirk
No spacers between pulley halves is the tightest setting, then you add spacers to make the pulley wider, and allow the belt to sit deeper in the groove and loosen the belt off.
So when you put a new belt in, put all but one of the spacers in to begin with, let it settle in, check your belt tension, and remove the spacers as required until the belt is tight. Repeat for belt #2.
Sound about right?
Kirk
Kirk
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07-31-2006, 05:44 PM
#8
Correct.
One caveat, you MUST have the correct number and thickness of spaces. Apparently the bolt only tightens correctly with the exact spacer count and width. If wrong, the bolt can come loose. That is why the spaces get moved not re-moved.
One caveat, you MUST have the correct number and thickness of spaces. Apparently the bolt only tightens correctly with the exact spacer count and width. If wrong, the bolt can come loose. That is why the spaces get moved not re-moved.
07-31-2006, 06:04 PM
#9
Three Wheelin'
Thread Starter
I was thinking of the spacers in terms of keeping the sprockets aligned to the bottom pulley. I forgot all about tensioning! Ooops!
Kirk
Kirk
07-31-2006, 06:13 PM
#10
Burgled
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I think you will find the belt is to tight without putting all the spacers between the pulley halves when new. maybe its just mine but thats what I have found.
07-31-2006, 06:16 PM
#11
Three Wheelin'
Thread Starter
Thanx for the info guys, I'll be putting it to use this weekend when I am home from work.
I just have to paint the outer casing for the fan black, and then I will be piecing it all together for install.
Kirk
I just have to paint the outer casing for the fan black, and then I will be piecing it all together for install.
Kirk
07-31-2006, 06:59 PM
#13
Burning Brakes
I'm sure you already know this, but there's a very specific procedure in the shop manual for fitting new belts involving the use of a belt tension gadget. There are two thicknesses of shims to allow for adjustment in very fine increments. I understand many feel confident that they can adjust the belts with their "calibrated thumb" but that engine is going to be just so beautiful it'd be a shame to get it wrong!
07-31-2006, 07:52 PM
#14
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Originally Posted by DarrylH
...there's a very specific procedure in the shop manual for fitting new belts involving the use of a belt tension gadget...
Marc
08-01-2006, 01:32 AM
#15
Three Wheelin'
Thread Starter
Thanx Marc,
I dont think I have to worry about tensioning any belts this weekend, (see rebuild thread) but I should probably buy one or a suitable substitute for myself. Where did you get yours?
Kirk
I dont think I have to worry about tensioning any belts this weekend, (see rebuild thread) but I should probably buy one or a suitable substitute for myself. Where did you get yours?
Kirk