Adjusting 6.5L TD Belt Tensioner

[markedz]

I have a 6.5L TD (96' Hummer H1). The belt tensioner needs adjustment. It takes a 1/2" drive to take the tension off and a star bit to tighten/loosen. There are markings on the tensioner and on the bracket. How do you adjust this properly? I had to loosen the bolt excessively to change the belt prior... Now it chatters and make all kinds of sounds.

[markedz]

It's the crank pulley making all that racket.

[a5150nut]

[quote=markedz]It's the crank pulley making all that racket.[/quot

AKA Harmonic ballancer

[diesel65]

There is going to be alot of argument on this,
The rubber damped crank pulley is not a harmonic balancer.
If you were to remove the rubber damped pulley and install a solid pulley such as I had on my 85', although one is serpentine and the other is v-belt, the engine will run just fine. The biggest problem I had on my 85' with the solid pulley was belt whip on the alternator belt causing the belt to loosen up. When I installed the 6.5 block in 97', I had found out about a GM service bulletin mentioning v-belt fatigue, the bulletin specified on replacing the crank pulley with the rubber damped pulley.

Markedz,
There is no adjustment on the tensioner, as you noticed the 1/2" square is used to R&R the belt, the star bolt (torx) is to fasten the tensioner to the bracket. The lines on the tensioner are a indicator to show when the serpentine belt needs replacement.

[sailun]

Harmonic Balancer lives between the crank pully, and the crankshaft.

Replace both.