Check it out...
Nothing like rolling down the highway doing the speed limit, pulling about 2 tons of trailer and equipment and then hearing a hollow metal sound bounce under the truck....U know tink tink tink... Now as we hear this sound we come up to a turn, wait steering is gone, it is now armstrong steering, puckering has begun...We make it thru the turn and now the battery light pops on, oh heck belt just got ate again...We are 30 minutes from home and traffic is just starting to pick up, will we make it home? Yes!... we do make it home but it is tough backing a trailer into the garage with no power steering. I unhook and pop the hood, see belt laying limp on the pulleys, cool saved me some money on another belt, it just slipped off. Well it did after the alternator pulley got owned. Take a look at these pictures and help me figure out what in the heck happened. What was a pulley is now a cone shaped piece of metal, nut, lock washer, pulley are gone. It did not go out quiet either, it took the tensioner pulley (wobbles real bad), the idler for the electric water pump, it too wobbles now. I am going to take the alternator back to the zone and see what they say...

 

update to my ongoing conversion problems. I took the alternator back to the zone and they swapped it out for me, ordered another motorcraft alt 8 rib pulley and a new tensioner idler pulley from rock. Tuesday I get the alt pulley and tensioner pulley on and go to put the same belt I had been using before my last issue and the belt will not fit. The two pulleys are the same size as the ones they replaced/same part numbers and all. I am thinking either the tensioner arm got bent up a little or the newly replaced alternator is setting about half and inch higher. Anyhow I could just barely slide the belt I have had on before my alt pulley killed itself and now there is no way. I guess I will try my other tensioner and see if that works, if not, I don't know what to try. I couldn't finde any belts a half inch longer (currently using k081265) otherwise I would just get one and be done with it.

 

Ford does sell a steel arm tensioner to replace the aluminum one.

 

thanks, I might look into that. I did swap out tensioners this morning and still no luck, the belt will not go on, I am pretty sure its the alternator again. I am thinking about going to a junkyard and pull an alternator out and see if that works, if it does I will have a local shop rebuild it to be on the safe side.

 

Well, it wasn't the alternator...I got one from a salvage yard today and the belt still wouldn't fit. I am at a loss, so instead of throwing more money at pulleys and such, I had a spare tensioner pulley that I swapped with the driver side idler pulley, its a wee bit smaller but works. The fit is tighter than before, I think now I have about 1/2 inch of slack but its on. I think I figured out why the belt was running off the pulleys and getting thrashed. The new pulley I got from south florida wasn't sitting flush with my snout, so I had to remove some material from the snout. The pulley is now flush and looks good to go. The final test will be doing some wot runs, maybe when I go into work tomorrow night.

 

Well, came into work tonight, I hit it hard for like 6 runs, didn't hear any ripping sounds this time. I get into work and pop the hood to inspect for any belt carnage. I still got 8 ribs on the belt and no wear or tear on the belt that I could see in the low light. I will hit it again a couple times going home this morning to see if it holds up.

 

I hope you have it licked.

 

Well, I have been running her pretty good trying to see if anything breaks, shreds or falls off, but so far so good. I did blow out my boost sensor or the gauge, its pegged at 30psi now, back to PLX for some warranty work.

I am confused on my belt shrinkage problem though, I had enough slack in the belt to use my spare tensioner idler pulley and get the belt on, today I checked and had some more slack, so I put the 90mm idler back on and its perfect. I have some play left in the belt but not much, just like it was before the alternator destroyed itself. So how the heck does it fit before my alternator died and then not fit two weeks later and now its fitting pretty good?

 

It depends on which pulley is the last one to have the belt slip over. If you try to slip it over a pulley that has a lot of belt wrap, say 195° you need more slack than a pulley that only has 45° of wrap.

.

 

10 days since my last update and we are still running great, no issues with the belts getting ate up or something else breaking...looks like we finally got it working.

 

we are still going strong, no noticeable belt slip, alignment issues, nor am I seeing large amounts of belt dust stuck all over the alternator and surrounding area like I had with the 6 rib setup. If anyone wants the parts list here it is...You might have to adjust for your application...

6 rib to 8 rib parts list

Motorcraft YB542 A/C compressor clutch pulley 42.89

Motorcraft GP720 Alternator pulley 12.99

Gates 38052 8 Rib idler pulley 16.38

Dorman 300006 Power steering pulley 22.79

Gates 38028 76mm idler pulley X2 use 1 for tensioner and my magnacharger needed 1 for idler 15.47

Gates 38022 90mm idler pulley x2 20.79

4081265 Goodyear gatorback belt for magna system 51.99
K081265 Gates belt for magna system 42.79

Dorman 594112 harmonic balancer it's 7" vs stock 6.5" may increase boost
a wee bit, I myself have the metco 7.5" 34.79

waterpump pulley, stock may work I have an electric waterpump so I cannot verify,
another possible part is F6TZ-8509-AA, one would have to locate that part, i couldn't find it on rock 14.92

then any upper supercharger pulley you want. I had south florida pulley make me an 8 rib 2.8 non-slip for 160.00

and various shims to fit on the bolt bosses where some of the pulleys mount, I personally had to shim the
two large idler pulleys, the v-ribbed pulley and my maggie idler pulley.

 

I know it's an old thread, but I have as well just finished this. I also have always had major slip even with 1/2 throttle. Thanks to Batn68 for his great parts list and trouble-shooting!!!! The water pump pulley he listed is same as the one we have now on our trucks, so stock one DOES work. So far no belt slip, tearing or anything.

 

Very nice

 

where did u get your upper pulley from?

 

South Florida PH, I think same place you did. Its been so long since I bought it I honestly have hard time remembering.