Okay here is the deal I have a 1988 F 150 4.9 fuel injected engine. The serpentine belt problem began with a noise. I replaced the belt with a NAPA brand belt made by gates. The alternator soon after went up, replaced it with a NAPA brand. Apx two weeks later the belts outer edge became worn, then destroyed by the fan. The tensioner assembly seemed bad so I replaced it and the belt. A few days later the belt does the same thing. Chedcked the power steering pump for play it needed replaced so I replaced it and the pulley. Put another belt on it and just the other day the belt did the same damn thing. I tried a belt last night and it went up. I know the water pump is fine, and the smog pump. The alternator pulley has the right amount of cogs or ribs on it. So what the heck is it? Any help would be nice, by the way I used the new flat pulley for the tensioner assembly ford had a recall for the old ribbed kind.

 

I had the same problem. Turned out to be loose bolts on my power steering pump mount. so I would assume that you might want to look for some loose bolts first then check your pully alignments.

 

thanx I will check that if not the problem any suggestions on pulley alignments?

 

In a chiltons or a chalmers guide. should tell you the pully depth also the way I do mine is measure depth on the water,alt and power steering pump. all 3 of these should be the same depth then place the belt back on and check by your eye to see any alterations in the belt ( ie not straight )

 

The 94 f150 that I am currently driving (not mine, thank goodness for the kindness of friends) was having the same type of problem. The local mechanic said that the pulley itself on the power steering pump was not receeded into the pump housing enough.

After some adjustments, it seemed to do the trick......

 

thanx for the suggestions some of which I never thought of. I guess I will attempt to make it to the dealership I work in, and at night pull it in my bay. I have the tool to press the power steering pulley on, what I plan to do is measure the depth of all 3 pulleys, if the power steering needs to go in more, I will press it in more if not then f it. Time to ask the shop foreman, I wondering if the dust cover on my tensioner is important, the pulley I bought from napa claimed it may cause intereference and it was best to leave it alone so I put the pulley without the dust cover on. I dont know Im sorry but if chevy's this old didnt rust out from the bottom up in this age range I would have bought one. Seems to me everyone who owns or had a ford returns on foot a whole lot more. This truck for 70k orig miles seems to be a rip off. Its reasons like this which justify me working on Toyotas, Lexus and Mercedes for a living. Contrary to what people think they are more basic mechanicly speaking and much easier to work on.

 

when you mean depth do you mean the distance from the mounting bracket to the end of pulley? or the distance from alt fan to end of pulley, water pump to end of pulley, and power steering pump to end of pulley thanx.

 

from the face

 

I had the same problem, it turned out to be a worn-out water pump. There was too much play in the shaft.

 

tensioner could be bad belt won't stay lined up and belts keep jumping

 

Anytime serpentine belts jump or slide off two things need to be looked at

1. Proper tension - a worn tensioner can allow for slack that will sling itself off any of the smaller pulleys (alternator especially).

2. Misalignment of pulleys, tensioner, etc. The way to check this is to put a carpenter's level against the face of the pulleys, and measure with a micrometer. The level should be flat, touching both sides each pulley as the other end of the level touches any other pulley. If there is any misalignment, the belt will side off.

This is because the rims of the pulleys are very shallow, as compared to the v-belt pulleys of yesteryear.

 

My 93 was eating belts for a while (3 in a week). Turned out to be the pulley on the tensioner was warn. I replaced the pulley. Problem is gone.

 

I appreciate everyones opinions, today I asked my shop foreman, and another master mechanic to help me with my problem. It appeared that the power steering pulley was the cause. If you were to observe the belts that were torn, two cogs or ribs were always missing. By more observance the tensioner was fine, for one it was brand new, secondly the pulley was a factory recall pulley (flat instead of grooved only a week old). The water pump seemed fine, I checked for play by the hand on the fan deal and alos the pulley had an even wear indicating the pump was okay. I also checked for leaks from the weap hole knock on wood none found. So then when we all looked at it closer, the power steering pulley was in to far, two ribs to far. We pressed the pulley off first although the pump was new we noticed or what we thought was too much play from the input shaft. A quater of an inch apx which to us seems to much play?
Suffice to say we then pressed the pulley back to where it needed to be and checked and measured the alignments. Started it up and instead of the instentaneous pull and ready to eat another belt, it ran straight and smooth. However it still leaves me with some question of concern, for when 1 week ago I replaced the pump the belt stayed on then it the problem resurfaced and belt eating began again. So now I will keep you posted. I still have some questions though, 1 what is the normal play from the input shaft on a ford? Secondly although kinda like askin for findin a needle in pile of chicken **** what could have caused the belt not to have got eaten up for one week with a misaligned pulley?

 

ps I hope this worked Im tired of selling my snap on an matco tools for belts and help.

 

serp belt.
i had this happen on a I6. went thru about 20 belts of every brand.
numerous tension and alignment checks proved fruitless. at idle belt ran
true,increased the rpm and it still look true. sometimes it would go a month
and not eat a belt,othertimes it would eat 2 a week. it was my daily driver,
so i could not leave it at a mechanic for days for them to find the problem.
use to carry 2 spare belts all the time. finally it broke down out of town.
had used up all my spares.towed to the nearest garage (firestone tire store).
i gave the mechanic all the backgound info. he was determined to find the
problem. he removed every thing on the front off motor. found the problem.
alternator bracket had a hairline fracture on one of the mounting bolts. at
idle and normal speed no misalignment, but at 2500-3000 rpm just enough
movement to eat-a-belt. i have the feeling my local dealership would
have replaced the whole front-end without finding the fractured bracket.
hope this helps you and others..dbr