Pulley Alignment

[FastFwd]

Dynoed the car Saturday and on the second pull just near redline the outer rib of the belt blows. Car is bone stock with just about 1300 miles on it.

Called SVT about it after the local LM dealer told me he couldn't work on SVT's. :cuss: They said they've never heard of a belt problem like that on a car with that few miles on it and I might have a pulley out of alignment.

I pulled the shroud off it and put a framing square over the pulleys. With the square flush across the blower pulley and the tensioner pulley they seem lined up perfect but the bottom pulley is about an 1/8 of an inch behind the straight edge as it crosses all three.

Can anyone tell me if they've run across this before and how could my bottom pulley be off?

The belt is sitting in the back 7 ribs on the bottom and tensioner pulley and the front 7 ribs of the blower pulley. The front rib on the belt is gone.

John

 

[Dana]

Do you know that the original belt was on correctly to begin with?
I know it is unlikely, but possible.

Get a new belt and start over again.

I don't think the faces of all the pulleys will line up exactly and with that many on there it is difficult to figure out which (if any) is wrong.

I would closely inspect the tensioner, its mountings and pulley. That is the most suspect piece.

Dana

 

[FastFwd]

Originally posted by Dana
Do you know that the original belt was on correctly to begin with?
I know it is unlikely, but possible.

Get a new belt and start over again.

I don't think the faces of all the pulleys will line up exactly and with that many on there it is difficult to figure out which (if any) is wrong.

I would closely inspect the tensioner, its mountings and pulley. That is the most suspect piece.

Dana

Dana I'm not sure that the belt was on correctly from the factory. I thought the same, unlikely but possible.

After the service manager at the LM dealer gave me the line about not being able to do warranty work on a SVT I decided to pick up a belt and put on my self. AutoZone and Advanced Auto had no listing for them. I'll try a different Ford dealer tommorow for a belt. If I have to go back to the place where I bought I will but they're 60+ miles away.

I would have thought the pulleys with ribs would line up but the bottom one seems to be set in compared to the tensioner and blower pulley. They both seem to be perfectly even by the straight edge. Can't tell about the alt pulley.

John

 

[slth69]

same thing just happened to me at the track friday night. Not sure what happened but there is only 5 ribs left on the belt.

I'm just gonna leave it, i'm getting the smaller pulley put on in 2 weeks so I was gonna get a new belt anyways!!!!

Guess the cars just gonna sit in the garage till then.

 

[Dana]

Get the Ford number and have AutoZone or what ever parts store you go to, cross it over. It is something pretty common. An 8 rib 74 1/2 inch belt or something like that. It should not be that hard to find in Gates or Goodyear.
Someone on the board will remember what the stock dimension is, if you can't find it. The OEM belt should still have the numbers on it or you should be able to measure it.

I probably should not state the obvious, but, check all the rest of the idlers and insure they spin freely and are true and parallel to the block, and the bearings are ok.
The alternator could be set back or forward too far. There were some changes to its location several months back.
The crank and S/C pulley are probably the least likely ones to be the cause. YOu could check to see that the S/C pulley is on far enough too.

Dana

 

[FastFwd]

Seeing how the straight edge contacts the blower and tensioner pulleys at four points with no gaps, two points on each pulley, they seem to be on the same plane. I just don't understand why the bottom pulley would not touch the straight edge while it is crossing and touching the other two in four spots.

I agree that the bottom would be the least likely to be off but I'd like to see another setuup so I could compare it.

I'll try to get the belt by length if I can. This one seems to be OK as long as I don't spin too high.Thanks for the replies.

John

 

[AMB]

Check ALL the IDLER puleys. There have FAILURES. I had a belt failure also, and the belt was slipping on the idlers. It wore the paint off them. They are not DESIGNED for HIGH RPMs.

AMB