Serpentine belt screaching!
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
Serpentine belt screaching!
Hello:
I have a 1995 F-150, I-6, 4.9 liter, 2WD truck. Today when I went to start it while at work, the serpentine belt was screaching like crazy. I opened the hood to find out that it was locking up.
1.) How do I loosen the serpentine belt (the easiest way) so that I can manually turn the wheels that are hooked up to the belt? Is there one component that can be loosened, thereby making this job a lot easier?
2.) Exactly how many devices are being controlled by this serpentine belt?
3.) Lastly, is there a part of component that more than likely is the culprit the majority of time when this sort of thing happens?
Like I said, the belt is locking up and it smells like burning rubber. I would like to fix this thing as soon as possible. Otherwise, I'll have to leave it at work for more than a day.
Thanks for everyone's help in the past. You guys have been super!
Steve
I have a 1995 F-150, I-6, 4.9 liter, 2WD truck. Today when I went to start it while at work, the serpentine belt was screaching like crazy. I opened the hood to find out that it was locking up.
1.) How do I loosen the serpentine belt (the easiest way) so that I can manually turn the wheels that are hooked up to the belt? Is there one component that can be loosened, thereby making this job a lot easier?
2.) Exactly how many devices are being controlled by this serpentine belt?
3.) Lastly, is there a part of component that more than likely is the culprit the majority of time when this sort of thing happens?
Like I said, the belt is locking up and it smells like burning rubber. I would like to fix this thing as soon as possible. Otherwise, I'll have to leave it at work for more than a day.
Thanks for everyone's help in the past. You guys have been super!
Steve
Cargo Master
Joined: Sep 2004
Posts: 2,687
Likes: 6
You definitely have a dried up pulley bearing. The tension in a serpentine belt is provided by what is called a tensioner pulley. One of the pulleys (I think it is in the middle of the engine toward the top) is spring loaded and pushes tension into the belt. Put a socket on it and remove the tension by torquing it yourself. Then remove the belt.
The belt turns all pulleys you see, a/c, power steering, water pump, alternator, and who knows what else.
The most likely item is the tensioner itself. It is the most likely to loose it's grease and become hard to turn. You can regrease it if you want but you'll only get a couple months out of it. You can buy a new one anywhere if thats the part you need. It could be anything else though. They all have bearings that can loose their grease. You'll know right away when you try to turn them. One will be hard to turn and will have a gritty feel. The only one it wouldn't be is the crank at the bottom of the engine. That's the guy that is powering the whole system.
The belt turns all pulleys you see, a/c, power steering, water pump, alternator, and who knows what else.
The most likely item is the tensioner itself. It is the most likely to loose it's grease and become hard to turn. You can regrease it if you want but you'll only get a couple months out of it. You can buy a new one anywhere if thats the part you need. It could be anything else though. They all have bearings that can loose their grease. You'll know right away when you try to turn them. One will be hard to turn and will have a gritty feel. The only one it wouldn't be is the crank at the bottom of the engine. That's the guy that is powering the whole system.
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
Check and make sure that there is a decal under the hood that shows the correct routing of the serpentine belt. If you have the decal-check and look for a spring loaded idler pulley---that is the thing that maintains the tension on the belt. You should see a square hole in the lever between the spring assembly and the idler pulley-use a 3/8 inch socket wrench handle and force the lever against the spring and this would release the tension on the belt and then remove it. Check all pulleys that they turn easily-with the exception of the crankcase pulley.
Or you could just idle the engine and check and see what isnt turning or is turning too slow.
(I posted the same time as Qman-same info.)
Or you could just idle the engine and check and see what isnt turning or is turning too slow.
(I posted the same time as Qman-same info.)
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
The tensioner pulley
Thanks for the quick response.
I'll give that a try and see if that is the problem. either way, the serpentine belt needs to be replaced anyway since it's eight years old and has about 75,000 miles on it. Nevertheless, the locking up of the belt is surely one of the pulleys. I will remove the tensioner pulley and see what happens.
Anyone else care to give their input?
Steve
I'll give that a try and see if that is the problem. either way, the serpentine belt needs to be replaced anyway since it's eight years old and has about 75,000 miles on it. Nevertheless, the locking up of the belt is surely one of the pulleys. I will remove the tensioner pulley and see what happens.
Anyone else care to give their input?
Steve
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
Check and make sure that you cant tell what is happening without removing the belt. If the belt is burning-something isnt turning that should-and a look-see should tell you immediately what isnt turning. You should also be able to tell by temperature-perhaps. Whatever is causing the belt to burn will be very hot to the touch-after letting the engine cool first by turning it off and then idling it for several minutes -and then turning the engine off again .
I had an old Oldsmobile and had the same issue-it turned out to be an alternator bearing was causing the alternator to lock up and the belt was turning thur the pulley--and the alternator pulley wasnt turning. I took a tire iron and placed it in the external fan of the alternator and turned the alternator several times. It freed up the alternator and it worked without a problem for 50k more miles.
I had an old Oldsmobile and had the same issue-it turned out to be an alternator bearing was causing the alternator to lock up and the belt was turning thur the pulley--and the alternator pulley wasnt turning. I took a tire iron and placed it in the external fan of the alternator and turned the alternator several times. It freed up the alternator and it worked without a problem for 50k more miles.
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
Hello Phone Man 91:
I have on page 1-20 of the Chilton Service Manual for this F-150 truck:
It says basically to to remove the bolt from the pulley that's located right before, and to the left of the power steering pump. There's an adjuster on top of the pulley to be pulled, but I am thinking this is for something else. Anyway, the pulley I am thinking of pulling out only has one large bolt holding it in. Is this the right one? And what is it called?
Steve
I have on page 1-20 of the Chilton Service Manual for this F-150 truck:
It says basically to to remove the bolt from the pulley that's located right before, and to the left of the power steering pump. There's an adjuster on top of the pulley to be pulled, but I am thinking this is for something else. Anyway, the pulley I am thinking of pulling out only has one large bolt holding it in. Is this the right one? And what is it called?
Steve
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
Do not remove the tensioner nor its pulley. Just use the square hole in the arm to compress the tensioner spring and then remove the serpentine belt.
I would suggest that you just check the belt with the engine running-it should be readily apparent where the trouble is.
I would suggest that you just check the belt with the engine running-it should be readily apparent where the trouble is.
Trending Topics
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
What do you mean by square hold?
Hello Phone Man 91:
Ok, so the square hole you're talking about, how is the compressed? Is this the item right above the pulley I just mentioned?
Steve
Ok, so the square hole you're talking about, how is the compressed? Is this the item right above the pulley I just mentioned?
Steve
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
I dont have my truck at my location-and my truck is a V8. But I think that all of the belt tensioners are the same. This square hole may be in a round housing that has the spring in it-this square hole allows one to place a 3/8 inch socket wrench in the hole and compress the spring-and then the belt will just fall off of the pulleys.
Give your cell number and I will call you.
Give your cell number and I will call you.
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
I finally found the section in the factory shop manual that addresses accessory drives-ie-serpentine belts and its tensioners.
Seems that you should put a wrench on the nut of the tensioner pulley and then push up on the wrench-in a clockwise direction.This compresses the spring and the belt will then just fall off of the pulleys.It takes a 16mm or 5/8 inch socket or wrench on this pulley nut.
There is an arm that is at a 7 oclock angle on this tensioner and this arm goes from the idler pulley to the round spring housing that is above the idler pulley of the tensioner. Remember to pull UP on the pulley nut on the wrench -not down.
It has been four years since I last did this-and I just forgot.
Seems that you should put a wrench on the nut of the tensioner pulley and then push up on the wrench-in a clockwise direction.This compresses the spring and the belt will then just fall off of the pulleys.It takes a 16mm or 5/8 inch socket or wrench on this pulley nut.
There is an arm that is at a 7 oclock angle on this tensioner and this arm goes from the idler pulley to the round spring housing that is above the idler pulley of the tensioner. Remember to pull UP on the pulley nut on the wrench -not down.
It has been four years since I last did this-and I just forgot.
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
It's not freezing up anymore!
Hello Phone Man 91:
I ran the truck through the loud screaching and found the problem. The bearings on the air pump (below the alternator) are the culprit. Finally, after having used some WD 40 earlier, the thing started to run fine; no screaching.
I am glad I had this problem because I need to replace the serpentine belt anyways. I found out that in order to remove it (according to the Chilton manual), that I have to turn a wrench on the tensioner pulley counter-clockwise. This is on page 1-20 of the Chilton Manual "Pickups and Bronco 1987-96 Repair Manual."
Thanks for all your help, but one last question. Since I was having this problem with the air pump, will this problem re-occur? If so, I may just replace it and get it out of the way before more stuff happens when I least expect it.
Steve
I ran the truck through the loud screaching and found the problem. The bearings on the air pump (below the alternator) are the culprit. Finally, after having used some WD 40 earlier, the thing started to run fine; no screaching.
I am glad I had this problem because I need to replace the serpentine belt anyways. I found out that in order to remove it (according to the Chilton manual), that I have to turn a wrench on the tensioner pulley counter-clockwise. This is on page 1-20 of the Chilton Manual "Pickups and Bronco 1987-96 Repair Manual."
Thanks for all your help, but one last question. Since I was having this problem with the air pump, will this problem re-occur? If so, I may just replace it and get it out of the way before more stuff happens when I least expect it.
Steve
Cargo Master
Joined: Jun 2002
Posts: 2,033
Likes: 32
From: Aurora,Colorado
Steve:
I feel kind of bad-I couldnt remember exactly how it worked until I checked the manual. My 1992 manual for the 4.9 says to lift up on the pulley nut to compress the tensioner spring-and it has a picture of the tensioner. It is possible that the tensioner changed from 1992 to 1996 for the 4.9-but I didnt think so. Anyhow-it will be apparent which way will loosen the belt.
And you are correct-you will need another new belt-especially after the burning and with 75k on the present belt. I would replace the air pump. It has more than 75k and you have a nice truck and it is worth it to make sure that the truck is dependable and that it has good emissions -to make the tree huggers happy!!
Good luck-hope that you can get the truck home from work alright.
I feel kind of bad-I couldnt remember exactly how it worked until I checked the manual. My 1992 manual for the 4.9 says to lift up on the pulley nut to compress the tensioner spring-and it has a picture of the tensioner. It is possible that the tensioner changed from 1992 to 1996 for the 4.9-but I didnt think so. Anyhow-it will be apparent which way will loosen the belt.
And you are correct-you will need another new belt-especially after the burning and with 75k on the present belt. I would replace the air pump. It has more than 75k and you have a nice truck and it is worth it to make sure that the truck is dependable and that it has good emissions -to make the tree huggers happy!!
Good luck-hope that you can get the truck home from work alright.
New User
Joined: Oct 2001
Posts: 4
Likes: 0
fix that pump bearing
I don't think a little WD-40 in the bearing is going to make your problem go away. When that pump locks up tight it will do a couple of things 1) destroy the belt if truck is running. 2) If truck isn't running you may not be able to start truck with belt on. I had a a/c compressor freeze up on my truck which locked it up tight with belt on had to remove belt to turn engine over. Fixed on roadside by installing belt for a non a/c truck. Limped truck home then bought new a/c compressor. Had Idle Tensioner pulley blow chunks this summer took water pump bearings with it. So keep on top of that serpentine belt. Rich
Thread Starter
|
Senior User
Joined: Nov 2006
Posts: 151
Likes: 1
Thanks everyone for your help!
Hello:
I love this forum. I have never been denied a response to all the problems I've had to repair on my F-150. I am an HVAC repairman and teacher by trade, so feel free to throw any questions my way if you guys ever need the help.
Steve
I love this forum. I have never been denied a response to all the problems I've had to repair on my F-150. I am an HVAC repairman and teacher by trade, so feel free to throw any questions my way if you guys ever need the help.
Steve
Fleet Mechanic
Joined: Mar 2005
Posts: 1,603
Likes: 1
From: St Louis
I had the A/C compress lock up on a 91 tbird. I was going 80 at the time, the car had a slight drag from load and then suddenly let go of the load. A/C was on high at the time and suddenly it was warm as could be. I pulled over and the clutch was locked up on the compressor but was not cooling at all. Luckly I drove home and didnt have a problem other than no A/C.
I would suggest getting a new air pump, or deleting it as a used one will give you an uncertain mileage before it does the same thing as your current one.
I would suggest getting a new air pump, or deleting it as a used one will give you an uncertain mileage before it does the same thing as your current one.