Serpentine Belt Tension
 

So on my 98' Disco I my serpentine belt simply fell off. Nothing appears wrong with it but a little scary having the truck essentially shutdown at 80miles an hour. 2 questions:

What could cause the belt to fall off ? - no breaks or cracks.

I"ve ordered a new belt and loosened the pully to install but cannot get the pulley to re-seat. What's the trick? There is too much tension. The new belt appears to be same size as old.


Thanks.


Pedro

Maybe the tensioner went bad?

do all your pulleys turn easily? A/C . Alternator, Tension Pulley etc.?
If you loosened the center bolt on the tension pulley that's not correct. You put a wrench on the nut/bolt on the pulley itself an d pull it toward the drivers side to get the belt on. Make sure the belt is on right. Discover Defender Maintenance Tips, Accessories, Parts & More at Roverparts.com

Your belt did not fall off. It most likely was thrown off by one of the rotating things locking up, unless route was incorrect or tensioner was mis-adjusted.

Problem is, to duplicate this you may have to run engine to warm up the other things that turn. If turning them by hand when cold does not show up anything, you could put belt back on, and listen to each thing that turns (other than crankshaft pulley) with a stick pressed against your ear. Let engine run for a few minutes and re-check. Will probably hear a different sound from the bad guy. Also, watch the fan pulley for wobble, it does that if water pump bearing is failing. See attached photo.

serp-
 

Thanks guys- will investigate and post findings. That illustration in RAVE is useless. Its unclear which bolt to lossen.

see attachd page, says clockwise to release.

It is difficult to get the belt on and easy to route it incorrectly. I had to pull on the tensioner bolt (clockwise) with a fairly long wrench while my son pushed the belt over the lip of the alternator pulley. You're pulling the tensioner using the bolt, nothing is taken off. In fact, you would be tightening the bolt, but you are pulling against the spring.

If you have no tension when moving the tensioner arm then it has failed.

serp.
 

Thanks for the illustrations. Looks like the tensioner is blown. Bleeding bearings. Ordered a new one from Advanced, which is having a good holiday sale online.