Belt Tension
Thread Starter
Racer
Joined: Nov 2009
Posts: 423
Likes: 7
From: Utah
Belt Tension
I can't for the life of me find what belt tensions should be. I know i could tighten until it's about right, but where can I find what they should be tensioned too? L-36 w/ Vintage Air A/C belt, Drive Belt, Power steering pump belt, and Alternator belt. I bought a tension tester and know how to use it, just can't find what force the belts should be set to (150 lbs, etc).
Anyone know where I can find the specs or a "good" tension should be?
Scott
Anyone know where I can find the specs or a "good" tension should be?
Scott
Thread Starter
Racer
Joined: Nov 2009
Posts: 423
Likes: 7
From: Utah
I looked in the AIM and Shop Manuals and found squat. I then picked up the Owner's Manual and found this on page 50.
"Check tension by applying moderate thumb pressure midway between pulleys. If the center to center distance between pulleys is 13-16 inches, the belt should deflect 1/2 inch. If the center to center distance is 7 to 10 inches, the belt should deflect 1/4 inch."
The weak link in this method is moderate pressure from me is different from moderate pressure from my wife. I figured w/ a tension tester I could remove measurements like "Moderate" and "Lightly".
"Check tension by applying moderate thumb pressure midway between pulleys. If the center to center distance between pulleys is 13-16 inches, the belt should deflect 1/2 inch. If the center to center distance is 7 to 10 inches, the belt should deflect 1/4 inch."
The weak link in this method is moderate pressure from me is different from moderate pressure from my wife. I figured w/ a tension tester I could remove measurements like "Moderate" and "Lightly".
Melting Slicks
Joined: Sep 2004
Posts: 3,223
Likes: 666
From: Northeast
In my 78 chassis manual it does give tension specifications. It is located in the chapter on engine cooling.
If this makes sense & help (to be used with a strand tension gage):
generator, AIR pump, P/S pump: adjust to 75 +- 5lbs used
........................................ .................125 +- 5lbs new
a/c compressor : adjust to 95 +- 5lbs used
.....................................140 lbs +- 5lbs new
Used belt means it has gone around once
Try the finger test and then the gage and see if it is about right.
If this makes sense & help (to be used with a strand tension gage):
generator, AIR pump, P/S pump: adjust to 75 +- 5lbs used
........................................ .................125 +- 5lbs new
a/c compressor : adjust to 95 +- 5lbs used
.....................................140 lbs +- 5lbs new
Used belt means it has gone around once
Try the finger test and then the gage and see if it is about right.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
"Moderate pressure" means to push the belt down with the end of your finger. If it doesn't hurt, then it's moderate pressure. "Heavy" pressure would mean that your finger would be in pain. 
But then, if you are 'Bubba', you could probably snap the d@mn belt off and not know it!
I always used the 'long belt run - 1/2" deflection; short belt run - 1/4" deflection' rule. If the belt works without slipping (squalling), great. If not, tighten a bit more. Tighten it too tight, and you'll wear out bearings/bushings quickly.
But then, if you are 'Bubba', you could probably snap the d@mn belt off and not know it!I always used the 'long belt run - 1/2" deflection; short belt run - 1/4" deflection' rule. If the belt works without slipping (squalling), great. If not, tighten a bit more. Tighten it too tight, and you'll wear out bearings/bushings quickly.
Thread Starter
Racer
Joined: Nov 2009
Posts: 423
Likes: 7
From: Utah
BINGO!!! Found it in the '69 Camaro/Nova/Corvette Chassis Service Manual in the Engine Specifications Section.
Same as in '76
Wouldn't it be nice if everything was in one reference book?
Thanks for the point out. I hope this helps some others too while they're searching for belt tensions.
Same as in '76
Wouldn't it be nice if everything was in one reference book?
Thanks for the point out. I hope this helps some others too while they're searching for belt tensions.
