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240 How tight sHould the alternator belts be?

digital.aaron

digital.aaron

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Feb 10, 2012
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turnin up the volume to 11 on the dial
I just finished switching out my alternator, but I'm starting to think I may have tightened the belts a bit too much. I took the car for a quick spin around the block after I got everything put back together, and I was thinking the car didn't sound quite normal. However I should mention that I removed my mechanical fan and fan clutch and installed an e-fan (it wasn't running), so I'm not sure how much difference that would make.

Anyway, I'd rather not break any belts, so I want to check to or row morning before I leave for work. Is there something about the deflection I should check? I was just giving it a bit of a tug and noticed it felt tighter that the a/c belt.
 
Yes, check the deflection on the tension side of the belts. They should not have more than 5-10 mm deflection when you push down or pull up on the tension side of the belt.
 
cleanflametrap said:
You're kidding??
Click to expand...

I wish I was.

8WaPb.jpg
 
So I may not need a complete new water pump, correct? I found the pulley in the parking lot and it looks like it's still in good condition. It didn't seem to pick up any rash when it came off. I'm just missing two studs from the water pump, but I'm thinking I want to replace all four. Would anyone happen to know exactly what kind of studs I'll need? Are they pretty easy to replace?
 
Doing a bit of Googling, I found a "maybe" answer of m6x1.0 for the studs. Does that sound right?

I've got two studs that were sheared off. One is missing the threaded section, and the other is gone all the way to the mounting plate. Is it even worth the time to try to extract these? Or should I just suck it up and buy a new water pump?
 
digital.aaron said:
Doing a bit of Googling, I found a "maybe" answer of m6x1.0 for the studs. Does that sound right?

I've got two studs that were sheared off. One is missing the threaded section, and the other is gone all the way to the mounting plate. Is it even worth the time to try to extract these? Or should I just suck it up and buy a new water pump?
Click to expand...

I think I see the problem. Before you posted the picture, I guessed this might have been the cause, and now that you have, verified my guess: Don't use the studs to mount the pulley. Remove them and use M6x12 cap screws (ordinary bolts). With the unthreaded portion of the studs protruding from the pulley now that your fan is no longer taking up the length, the nuts never cinched the pulley to the water pump flange.

You should be able to easily extract the studs using vise grip pliers. Piece of cake. Well, I missed that flush one on the top. That should still come out easily, but getting to it means removing radiator I suppose unless you can slot it with a dremel cutting wheel.
 
cleanflametrap said:
I think I see the problem. Before you posted the picture, I guessed this might have been the cause, and now that you have, verified my guess: Don't use the studs to mount the pulley. Remove them and use M6x12 cap screws (ordinary bolts). With the unthreaded portion of the studs protruding from the pulley now that your fan is no longer taking up the length, the nuts never cinched the pulley to the water pump flange.

You should be able to easily extract the studs using vise grip pliers. Piece of cake. Well, I missed that flush one on the top. That should still come out easily, but getting to it means removing radiator I suppose unless you can slot it with a dremel cutting wheel.
Click to expand...

I want to buy you a beer. :cheers:
Thank you for explaining how I failed. It never even occured to be that the pulley wasn't cinched to the flange.

I'm going to have to fix a coolant leak anyway, so I may just remove the whole radiator. Then all I should need is a screw extractor bit, correct?
 
cleanflametrap said:
I think I see the problem. Before you posted the picture, I guessed this might have been the cause, and now that you have, verified my guess: Don't use the studs to mount the pulley. Remove them and use M6x12 cap screws (ordinary bolts). With the unthreaded portion of the studs protruding from the pulley now that your fan is no longer taking up the length, the nuts never cinched the pulley to the water pump flange.
Click to expand...
Haha, guessed it also! Just make sure the new 6 mm bolts are not too long. They only need to be 8-10 mm long, 12 will work, but you don't want the bolts to hit the wp bearing.

I like to add the B21 fan flange on the front of my wp pulley, which adds thickness to use the orig studs and is there to quickly put a mechanical fan on when the e-fan craps out. :-P
 
vvpete said:
Haha, guessed it also! Just make sure the new 6 mm bolts are not too long. They only need to be 8-10 mm long, 12 will work, but you don't want the bolts to hit the wp bearing.

I like to add the B21 fan flange on the front of my wp pulley, which adds thickness to use the orig studs and is there to quickly put a mechanical fan on when the e-fan craps out. :-P
Click to expand...

Here is a good rule of thumb if you dont have the proper gage or experience to know how tight to tighten a V belt:

You should be able to twist the belt a half turn on the longest segment (greatest length between pulley contact). If it turns farther than this your belt is too loose, if it doestn turn a half turn its probly too tight.
 
cleanflametrap said:
I think I see the problem. Before you posted the picture, I guessed this might have been the cause, and now that you have, verified my guess: Don't use the studs to mount the pulley. Remove them and use M6x12 cap screws (ordinary bolts). With the unthreaded portion of the studs protruding from the pulley now that your fan is no longer taking up the length, the nuts never cinched the pulley to the water pump flange.

You should be able to easily extract the studs using vise grip pliers. Piece of cake. Well, I missed that flush one on the top. That should still come out easily, but getting to it means removing radiator I suppose unless you can slot it with a dremel cutting wheel.
Click to expand...

Very nice diagnosis , I missed that he went to e-fan and left clutch fan studs...
 
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CerebralAilment said:
Haha woah 2 belts!! I only have 1 =X
Click to expand...

240's have 2 belts, 740/940 use 1

Also to the OP, those are not Volvo belts!
FWIW, I bet I paid less for the good Volvo belts than most of you pay for the supposedly super Gates belts in that pic. To properly tension the belts, the cogs or notches need to be inside the pulley diameter. Have run into problems with those type of belts running too high in the V-groove of the pulley and wear out prematurely.
 
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