Belt squeal when I deck it

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
So I've noticed that when I really deck it off the line a belt likes to squeal when the RPMs drop going into second gear. Any idea why this would happen? It never happens any other time, just in that situation. I only have two belts at the moment, one V-belt for the PS pump and one flat belt for the alternator. No A/C or air pump. Both belts are about 2 years old and still look brand new. Both are quality gates belts. Any idea why this happens?
 

CSFJ

-----------------
Supporting Member
Joined
Jul 1, 2014
Posts
6,160
Reaction score
5,162
Location
------
First Name
-------------
Truck Year
-------
Truck Model
-------
Engine Size
-------
Residue on the pulleys perhaps. Had one years ago, that wouldn't stop squealing until I wire brushed the pullies with solvent.
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,789
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
Is your PS pump fixing to **** the bed and causing the belt to slip, or PS hoses collapsing internally, is your PS fluid low and foaming at higher RPM or water pump any one of these could cause drag. Or if it's the serp. belt your alt. Or water pump could be losing a bearing.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
Hmm. I have not cleaned the pullys recently. I'll have to do that.

The PS pump is the same age as the belts, and all of the PS hoses are about 3 months old, I changed them when I changes the hydroboost. I also have an inline PS fluid filter and cooler.

No idea about the water pump or alternator. They do look fairly old. I've had the truck maybe 4 years and they came with it. All I know is they both seem to work fine.

Honestly this is the only time anything makes any kind of noise in the engine bay. Its weird.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
So I'm thinking this may not be a belt issue. It happen again yesterday and I paid close attention to it. It seems it did it when the engine over-revved and then had to drop down in RPMs fast to then engage second gear.

So... reeeEEEEVVVVV spool down/squeeeelll then 2nd engages.

This does not seem like normal operation does it?
 

chengny

Full Access Member
Joined
Feb 22, 2012
Posts
4,086
Reaction score
1,008
Location
NH
First Name
Jerry
Truck Year
1986
Truck Model
K3500
Engine Size
350/5.7
I only have two belts at the moment, one V-belt for the PS pump and one flat belt for the alternator. No A/C or air pump. Both belts are about 2 years old and still look brand new. Both are quality gates belts. Any idea why this happens?

Just a thought, and I know it isn't for everyone but:

If you feel comfortable with it (and only do it for a short time), you might consider removing each belt - one at a time - and doing a test run. Maybe remove the water pump/alternator belt first - just because it's the most forward and easiest to pull. Crank it up and take it out for a few minutes.

If the squeal is gone...something with that belt (or something driven by the belt) is the issue. You might not know exactly what the issue is but at least you'll know where to start.

If the squeal remains, remove the PS belt and see if that makes the noise go away.

Also, I would leave the alternator pump belt off while you do the PS test. That way - if with both belts removed - you still get a squeal, you can eliminate the entire belt/pulley group - as well as the alternator, water pump, PS pump and power steering hydraulic system - as the source.
 

Forum statistics

Threads
42,102
Posts
909,124
Members
33,586
Latest member
ssgmike
Top