Thrown belt

[Goofyexponent]

Any of the pulleys belt, or mis-aligned? What about the installation of the new idler and tentioner? Are they square and runnning true? Just some thoughts..

My truck threw the belt once, and hasn't done it again.....but now that I've said that...

 

[ghunt]

Nothing LOOKS misaligned, and that's what's so infuriating about it...it rides in the center of the tensioner pulley, and yeah it rides on the outer edge of the idler pulley but that's where it rode on the old one too. When I stand there and watch it running it looks fine. Even if I rev it up it doesn't do anything funny, the belt doesn't jump around or anything.

Maybe I just need to shim out my idler pulley a little like was mentioned. Either that or try a tensioner pulley on there, I just don't really want to spend another $18 for another pulley.

 

[Goofyexponent]

I would try that. It may be just what the doctor ordered.

 

[typ4]

water pump leaking/loose??

 

[ghunt]

Nope, neither.

 

[Fozz]

If you found coolant on your pulleys, that's probably the problem. Double-check your upper hose connection. Or (I just had this problem), my upper radiator tank was leaking. Maybe you have a leak, but it's not evident until you drive the truck (build pressure). Once you're driving, between the fan pulling air flow and the air flow while driving is causing you coolant leak to find it's way on your pulley causing the belt to jump. I've pitched a belt troubleshooting a belt squeak using WD-40. The pulleys don't like ANY moisture it seems. I guess rain doesn't make its way to the belt system causing issues?

 

[ghunt]

Well, I'm not sure what's going on with my radiator. I only found coolant on the upper pulleys that one time (2 days ago) where it looked like it had come from the upper hose connection, yesterday I drove home without incident, looked at it when I got home and that whole area was dry, in fact it hardly looked like it had been leaking at all. And this morning I drove in without any problems.

So, I have no clue. I guess the radiator needs replaced, but if I can hold off until spring I'd like to.

Also, last night I put a washer behind the idler pulley, which moved it out just enough that the belt is riding in the center of the pulley now.

 

[WrickM]

It's kinda good, and weird that whatever happens to my truck i come here and there is a post about it on the front page. . .

I guess i am grateful for the multiple belt setup on my "87. On the way to work i lost two of them. The Alt to Vac and crank/fan to Alt. Was able to get them changed in the NAPA parking lot with borrowed tools in about 30mins. Not bad since i had never really looked at how they went on. Mine came off because the crank/fan to Alt belts was far too loose and i was too lazy to fix it.

 

[franklin2]

I agree, I like the redundancy of the v-belt setup. Some people want to change to the later model serpentine setup and I try to discourage it. A guy I work with has been stranded twice because of his serpentine belt setup. Once for the A/C clutch flying apart, and once because his idler flew apart.

If the A/C clutch failed on the v-belt setup, I believe you probably could still make it home if it didn't take out any of the other belts.

 

[zigg]

Man 'o man....

Well, mine has thrown the belt 3 times now. First time, it took out the tranny lines, and dumped the tranny fluid all over the ground, second time, the wires to the fuel pump (sigh). 3rd time, the tensioner was leaned over and tapping the fan, so it was obvious there was an alignment problem. So, after re-routing hoses and wires,
Long story short, after several belts and pulleys, figured out that the brass bushings on the bolt for the tensioner had worn out, allowing the tensioner to tilt forward enough to mis-align, and threw the belt. I also figured out that the bolt had partially sheared, might be part of the same problem, but in the end, need a new tensioner and bolt...in the meantime, I drilled out and tapped the bracket, to put a new bigger bolt on, and then had to re-bush the tensioner to accomodated(total cost about $2) instead of $300 from ford for their new tensioner...

 

[WrickM]

and Zigg confirms for me why i want to keep my V-belt setup. I feel like sometimes we "upgrade" just for the sake of doing something

 

[Brad S.]

ghunt,
A few years ago I had similar problem, belt would get 2 or 3 of the grooves stripped off the belt. I took the belt off and spun each pulley to find out which one was bad or bent.
Turned out the A/C pump pulley had a very slight wobble or bend in it. After I replaced it's run ok since.
I hate the mystery problems.

 

[93_444idi]

i had a similar issue and mine was the tensioner. if you buy a new tensioner get a factory ford one, they have thicker springs and wont allow as much play as aftermarket ones

 

[ghunt]

Somebody on another forum told me that if you replace the tensioner and/or idler pulley and don't scuff the surface, that the tiniest amount of moisture can cause it to throw the belt. I didn't know that and I think that's why it threw the belt those other times...hell, it would throw the belt when I put belt dressing on it.

 

[icanfixall]

Fix the leaking radiator.... Seems you already have answered your issues. A wet slippery serpentine belt will throw off. So... Coolant is very slippery... Belt comes off..... HMMMM Fixing the radiator is not like just throwing money at a problem hoping it will fix it... You know there is a problem. Look at your tensioner. On the front of it there is an adjustment mark. See that you have the proper length belt and its between those marks.