Recently had to changed drive belt as when switching on climate control(air con)the inner part of the Air Con drive wheel sometimes locks for a split second. The drive belt then flies off. The tensioner works fine so all ok there. Needless to say haven't touched Auto button since last shreddered belt. Can anyone shed some light on this. On the plus side this has ment a couple of trips down to halfords to buy new tools ( the male equivalent to makeup)and the wife and kids get to sit on the sofa while yours truly gets his hands dirty
Chewed Drive Belt.
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Welcome to Saabscene!
A colleague of mine had a similar problem recently. His belt was chewed on one side (actually, one rib was missing from the offside, as far as I could see), and although I put the belt back on correctly, as soon as the air con compressor clutch engaged, the belt jumped across. My diagnosis, confirmed by the dealer, was the tensioner. The tensioner is also a damper, so even though it tensions, it can still be useless in the damping department. It should be very very difficult to compress. The damper acts when the load on the belt changes. The greatest load change occurs as the compressor clutch engages and disengages. Without adequate damping the belt gets upset and jumps.
The original Saab damper is expensive, but seems better than the after market parts that are available. If you are going to replace the tensioner/damper, have a very good look at (& listen to) the tensioner and idler pulleys. The bearings do not last forever, and it's well worth changing anything suspect whilst you are at it.
A colleague of mine had a similar problem recently. His belt was chewed on one side (actually, one rib was missing from the offside, as far as I could see), and although I put the belt back on correctly, as soon as the air con compressor clutch engaged, the belt jumped across. My diagnosis, confirmed by the dealer, was the tensioner. The tensioner is also a damper, so even though it tensions, it can still be useless in the damping department. It should be very very difficult to compress. The damper acts when the load on the belt changes. The greatest load change occurs as the compressor clutch engages and disengages. Without adequate damping the belt gets upset and jumps.
The original Saab damper is expensive, but seems better than the after market parts that are available. If you are going to replace the tensioner/damper, have a very good look at (& listen to) the tensioner and idler pulleys. The bearings do not last forever, and it's well worth changing anything suspect whilst you are at it.
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14,305 Posts
Replacing it is not too difficult, but you do need to compress the tensioner to fit the belt. Saab to a special tool for this, or the one shown in the Haynes manual will work. I've also managed it with a large G clamp.
Access is by removing the RHS wheel and arch liner. The front one of the two pulleys has a LH thread.
Access is by removing the RHS wheel and arch liner. The front one of the two pulleys has a LH thread.
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416 Posts
I'll be changing my belt at the Kodak meet. Should I get a G-clamp too?
Mark
Mark
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218 Posts
Mine did this too. Started chewing up on one side (can't remember which) after I had various issues with the top bolt on the tensioner. It was shredding for about 3-4 weeks and eventually the tensioner broke off and I drove over it in the New Forest one day. How the AA man laughed!
My suggestion is to replace the whole tensioner assembly (about £120, only from Saab) as the brackets are prone to fractures and the belt chewing is a symptom of the whole assembly going out of alignment before it breaks.
Get all the bolts replaced as well as they can take some stress and fail also.
My suggestion is to replace the whole tensioner assembly (about £120, only from Saab) as the brackets are prone to fractures and the belt chewing is a symptom of the whole assembly going out of alignment before it breaks.
Get all the bolts replaced as well as they can take some stress and fail also.
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218 Posts
Oops just read the whole post.
You can't use the Haynes tool to compress the tensioner assembly you need a Saab tool or I think BillJ said something about using a trolley jack to compress the tensioner to get the belt on. If you have a friendly dealer ask to borrow their tool. I did and made one up, I had better dig the photos out tonight and post them up.
You can't use the Haynes tool to compress the tensioner assembly you need a Saab tool or I think BillJ said something about using a trolley jack to compress the tensioner to get the belt on. If you have a friendly dealer ask to borrow their tool. I did and made one up, I had better dig the photos out tonight and post them up.
Its is very likely that your A/C pump is on its way out. The pump works by having several small pumps which are driven by the drive shaft. If one of these pumps goes wrongs then it can do one of two things:
1) go very stiff - in which case your A/C clutch fries itself
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2) Seizes - in which case your A/C clutch bursts into flames or the belt comes off.
A refill on the A/C with added lubricant may ease the sticky cylinder... or it may not.
A recon A/C pump and gas refill is a few hundred quid.
Steve
1) go very stiff - in which case your A/C clutch fries itself
2) Seizes - in which case your A/C clutch bursts into flames or the belt comes off.
A refill on the A/C with added lubricant may ease the sticky cylinder... or it may not.
A recon A/C pump and gas refill is a few hundred quid.
Steve
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218 Posts
Three posts in a row, must be a record! Probably not.
Anyway try this Word document as a link to the tool. Sorry it is about 1.1MB at present. If anyone wants to PDF it for me and e-mail back I will repost.
It is by no means finished but might give a few ideas as to the tool diagrams. I will finish it sometime and take any questions (e-mail on the document) about the tool.
If anyone (BillJ maybe) wants it for their website please take it and I will post updates as they occur.
Enjoy
Duncan
Anyway try this Word document as a link to the tool. Sorry it is about 1.1MB at present. If anyone wants to PDF it for me and e-mail back I will repost.
It is by no means finished but might give a few ideas as to the tool diagrams. I will finish it sometime and take any questions (e-mail on the document) about the tool.
If anyone (BillJ maybe) wants it for their website please take it and I will post updates as they occur.
Enjoy
Duncan
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218 Posts
Duh, I need to put the link on. Sorry had a bad night, up marking students work until 1am and I am really not corpus mentis today.
Saab Tensioner Tool
Saab Tensioner Tool
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218 Posts
That type is brilliant and easy to make but only useful when you are changing the belt and have the belt on so you can force the tensioner using the belt. The problem comes when you want to change the whole tensioner unit you must compress it and uncompress it without the assistance of the belt. That is what the Saab Tool is designed to do.
I know my welding is not up to much but it does work very well.
I know my welding is not up to much but it does work very well.
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