Belt/Pulley issues after alternator upgrade
02-21-2017, 11:35 AM
#1
Junior Member
Thread Starter
Belt/Pulley issues after alternator upgrade
hello folks. I have a handed down '94 F150 with an inline 6 (and 315k miles on it!). I was told to upgrade the alternator from 2G to 3G on another forum. I was finally able to do that this weekend albeit a few sore muscles and many returns to find the right serpentine belt size.
A neighbor was helping me with the tensioner. We got it on, but at the first try of starting it up and pressing the gas, the serpentine belt would hang over by one rib at the power steering pulley. I shut it off, we fixed it and tried again. This time when pressing the gas it stayed on, so I took it for a drive up the street. After a short distance at 25-30 mph I got to the top of the hill, shut it off and checked again, and the belt was hanging over by one rib at the power steering pulley again.
I wrote back on the other forum asking if a shorter belt would help increase the tension and possibly stop it from coming off at the power steering pulley, or if I just needed a washer against something to balance it out. The person there said I might have a misaligned pulley. here's more details though:
1. The old alternator was a 2G and was snug in the bracket where the alternator sits. It's bottom pivot point sat in the right hole (the bracket has a left and right hole) and the other hole on the upper right (1:30 position). The new alternator doesn't fit in the same position. I have to put it in the pivot hole on the left in the bracket while the other hole is secured at the 12 0 clock position). I know the pulley on the 3G alternator is the same as the one on the 2G and am aware I can replace the pulley on it, but I can triple-check the size.
2. All the pulley's have 6 ribs. When I looked up the serpentine belt number for Advance Auto Parts, it listed 4 options with and without A/C, and thanks to someone deciphering the numbers on the belt, the stock product showed the belt having 6 ribs. However, the old belt that was on it had 5 ribs. My Uncle used this truck to haul pianos and organs back and fourth across the country when he was restoring those. I don't know when the last time he used it before I did, so I don't know if he or someone else intentionally got a shorter-ribbed belt knowing there was an issue with it jumping slightly over the P/S pulley. The old belt too was starting to become a little frayed on the edges, so I wanted to just put in a new one anyway.
Is it possible to replace the tensioner wheel with a wider one? Does it make sense to try and find one with a lip or flange on it or would that be disastrous because of the belt wearing out from rubbings against the flange? Is it okay to go back to a 5-rib belt when all the pulley's have 6 valleys since that's the kind of belt that was on there before?
The truck is no longer a daily driver (was used as a DD months ago when my girlfriend's son needed a vehicle to get to work, but now has his own car). I keep the truck around for something non-computerish to work on, plus I like having that feeling of accomplishment when I can fix something, followed by the burst of confidence, then the crushing blow of disappointment when I run into something I can't fix. My gf and I use it to get stuff from the hardware store to fix up the house or to take in or get rid of old furniture. Still, I'd like to hold on to it if only a few simple fixes are required. Thank you for your help!
A neighbor was helping me with the tensioner. We got it on, but at the first try of starting it up and pressing the gas, the serpentine belt would hang over by one rib at the power steering pulley. I shut it off, we fixed it and tried again. This time when pressing the gas it stayed on, so I took it for a drive up the street. After a short distance at 25-30 mph I got to the top of the hill, shut it off and checked again, and the belt was hanging over by one rib at the power steering pulley again.
I wrote back on the other forum asking if a shorter belt would help increase the tension and possibly stop it from coming off at the power steering pulley, or if I just needed a washer against something to balance it out. The person there said I might have a misaligned pulley. here's more details though:
1. The old alternator was a 2G and was snug in the bracket where the alternator sits. It's bottom pivot point sat in the right hole (the bracket has a left and right hole) and the other hole on the upper right (1:30 position). The new alternator doesn't fit in the same position. I have to put it in the pivot hole on the left in the bracket while the other hole is secured at the 12 0 clock position). I know the pulley on the 3G alternator is the same as the one on the 2G and am aware I can replace the pulley on it, but I can triple-check the size.
2. All the pulley's have 6 ribs. When I looked up the serpentine belt number for Advance Auto Parts, it listed 4 options with and without A/C, and thanks to someone deciphering the numbers on the belt, the stock product showed the belt having 6 ribs. However, the old belt that was on it had 5 ribs. My Uncle used this truck to haul pianos and organs back and fourth across the country when he was restoring those. I don't know when the last time he used it before I did, so I don't know if he or someone else intentionally got a shorter-ribbed belt knowing there was an issue with it jumping slightly over the P/S pulley. The old belt too was starting to become a little frayed on the edges, so I wanted to just put in a new one anyway.
Is it possible to replace the tensioner wheel with a wider one? Does it make sense to try and find one with a lip or flange on it or would that be disastrous because of the belt wearing out from rubbings against the flange? Is it okay to go back to a 5-rib belt when all the pulley's have 6 valleys since that's the kind of belt that was on there before?
The truck is no longer a daily driver (was used as a DD months ago when my girlfriend's son needed a vehicle to get to work, but now has his own car). I keep the truck around for something non-computerish to work on, plus I like having that feeling of accomplishment when I can fix something, followed by the burst of confidence, then the crushing blow of disappointment when I run into something I can't fix. My gf and I use it to get stuff from the hardware store to fix up the house or to take in or get rid of old furniture. Still, I'd like to hold on to it if only a few simple fixes are required. Thank you for your help!
08-09-2020, 04:30 PM
#2
Senior Member
Here's some info hope it helps??.......In the early 90 years (mine was a 91) ford p/u's had a alignment issue with the power steering pulley's.
I bought my new trk & 2 days later went to pick it up on a saturday....It had a slight belt squeal....was told take it & drop it off Monday...
They realigned the power steering pulley (or complete pump I don't really know what they did to fix......There was a recall on above fix !!
So Power steering pump can be aligned....Maybe all it needs is to move it forward or back to suit your needs???
If a 5 rib belt works fine I also would be tempted to go that route also....Good Luck !!
I bought my new trk & 2 days later went to pick it up on a saturday....It had a slight belt squeal....was told take it & drop it off Monday...
They realigned the power steering pulley (or complete pump I don't really know what they did to fix......There was a recall on above fix !!
So Power steering pump can be aligned....Maybe all it needs is to move it forward or back to suit your needs???
If a 5 rib belt works fine I also would be tempted to go that route also....Good Luck !!
Last edited by maco; 08-09-2020 at 04:33 PM.
08-09-2020, 06:47 PM
#3
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The number of ribs is one thing; the belt length is entirely separate.
All these trucks take 6-rib belts, period. Don't put the wrong tensioner or idler pulleys on.
One set of holes in the bracket is for the small-case (95A) alternator; the other set is for the large-case (130A). But your photo is from the wrong side of the engine for us to see the alternator, or how it's installed; and it's very small. You also neglected to post a pic of the original alternator. The more & bigger pics you post, the more likely we can help you find the problem.
If the belt is coming off at the PS pump pulley, that's the place to start checking alignments. You should be able to sight along the pulleys, and see that they're all in the same plane. Any or all of them can be misaligned for various reasons, so there is no absolute reference. But the best one is probably the A/C compressor pulley since it's the least-likely to be off-plane.
All these trucks take 6-rib belts, period. Don't put the wrong tensioner or idler pulleys on.
One set of holes in the bracket is for the small-case (95A) alternator; the other set is for the large-case (130A). But your photo is from the wrong side of the engine for us to see the alternator, or how it's installed; and it's very small. You also neglected to post a pic of the original alternator. The more & bigger pics you post, the more likely we can help you find the problem.
If the belt is coming off at the PS pump pulley, that's the place to start checking alignments. You should be able to sight along the pulleys, and see that they're all in the same plane. Any or all of them can be misaligned for various reasons, so there is no absolute reference. But the best one is probably the A/C compressor pulley since it's the least-likely to be off-plane.
