How tight to make the fan belt?

[Guest]

Any advice on how-tight to make the fan belt? I know if it is too tight it can kill the waterpump in short order. Any help is appreciated!

Thanks

Lee

[Mike Self]

of play in the belt run between the water pump and alternator. Before adjusting, check the alternator mounting bushings--the original rubber ones turn into black goo; that'll cause the alternator to cock at an angle, thus causing accelerated belt wear and making adjustment more difficult.

You can buy replacement urethane bushings that will last indefinitelly; that'll make your job a lot easier, and your fanbelt last a lot longer...

mike

[02fanatic]

I have to tell you....this is one of those "fly by the seat of your pants" things. Mike, with all due respect, figuring out "where 1/2-inch is" is next to impossible in real life - unless you have a belt tension gauge.

Here's what I do: leave the belt obviously too loose and run the engine and accelerate....you will get a "squeel" no doubt from slippage. Keep tightening the belt up until the "squeel" stops....do this on a "cold engine".

I know this works, as I have retightened Hugo's belt about a dozen times before the squeel went away! :-)

You should also have a feel in your gut if the belt is too tight...as you won't be able to depress it at all.

I know, this isn't not very scientific, but it works! All the comments about bushings apply obviously.

John

[PSloan]

I've been told that if you can turn the belt 1/4 turn while mounted it is tight enough - I've found that this works OK

[Mike Self]

fanbelt (taught me by my father-in-law who started mechanicking back in Model T days): lay a straightedge (a paint stirrer will work) on the fanbelt, push down on the middle, and try to insert anything a half inch in diameter between belt and straightedge (I use a 1/4" drive socket of the proper OD).

But you're right, it doesn't have to be exact. I usuallly use my thumb vs a socket. Bottom line is tighten it just enough so the belt doesn't slip, even when wet, and you're good to go. If it squeals, it's too loose; if you go thru water pumps in 10k miles, it's too tight. Loose is good.

mike

[eastsidebimmer]

(nt)

[eastsidebimmer]

(nt)