Fan belt questions

reek29

reek29

Member
I have two 29's, both with the same fan belt problem. When I install a new fan belt, everything is fine. Once the belt gets some mileage on it, it stretches a little. When I tighten it, the belt almost touuches the bottom radiator hose. I have taken to positioning the hose clamp directly under the belt so if the belt bounces a little, it won't cut the hose. Does anyone make a belt that's a little shorter? I buy my belts from Snyder's, and have no complaints except what's stated above. If the belt were an inch shorter, it would be fine.
 
Not to long ago auto-zone had in their store a set of pully's you could put your old fan belt on and it would tell you the size of it, then you could buy one a little smaller or larger, or you could just compair your old one to some of their belt's untill you find one a little smaller. good luck.
 
The only thing I think I know is that it's 43". The reason I say "I think I know" is because the Mike's catalog says 43". I can't find a listing in any catalog I have that offers two sizes.
 
Not sure of the length, but the belt I was told to get when I needed one was GATES BX40. Maybe some one else will chime in with a different P/N or verify this one. Hope this helps.
Paul in CT
 
Have you checked the springs in your front motor mount. I had the problem of the belt hitting the hose on myAA and the springs were bad. replaced them no more problem
 
Are you using an alternator with a pulley smaller that the original generator pulley?
Smaller pulley, different position from stock could need different from stock belt --does the belt fit the pulleys to the top?,

A rusty pulley will eat belts also.(worn belt will ride low in the pulleys)

With the generator I have not had to adjust the belt in any years, and it doesn't need to be very tight ---in fact I can not remember needing to adjust it in the last 10 years, and I guess I got a good belt ---perhaps it has been 25 years.

With an alternator and a small pulley there is not much contact, and with the higher hp and speed the alt needs you will need a tighter belt to prevent slipping --if you can turn the alt, or gen pulley with your fingers it is too loose, the belt is worn, or the pulley is worn--or a design issue --not enough wrap, a belt grips a pulley because the rubber swells when it is bent, if the pulley is worn (concave sides) it will not grip, and will slip soon after an adjustment, a smaller alt pulley has less surface area --slips easier

Other posts in the past talk about a shorter belt for alt.
 
Check out these numbers - Napa Fan Belt (A) 25-20426, I think this is standard and they can look up numbers from there to go bigger/smaller. Gates TR 22426 and Gates TR 22425 for a slightly smaller size for an alternator. I have a better list someplace but can't find it.
 
If the pulleys are worn that will do it. If the springs are worn that will do it. If we are getting belts made in BUM F--- Egypt that will do it. To check the length of a belt measure the outside diameter with masking tape. To check the pulleys put a straight edge on the inside v groove they should not be concaved. If the belt sits to deep in the v they are worn the belt should be level with the top of the pulley or slightly above. Just my opinion.

Need a 27 roadster deck lid.
 
The belt I ordered from Mac's fit very tight-I had to take the pulley off the generator to get it on. My guy that rebuilt the engine is going to get me one that is the correct length. Don't know what that is yet.
 
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