Peterbilt 379. Fan clutch was replaced 3 years ago. ITs always had this loud annoying screech when it engages. Would like to finally figure it out. Few notes: ITs not the fan belt or the tensioner. I replaced all that thinking it was the issue. The noise is indeed coming from the clutch when it engages.
Hmmm. That’s not the clutch making noise. That noise is the air releasing from the fan clutch solenoid valve.
Horton or Kysor?-Serpentine or V-belts? Unfortunately when manufactures started using 30" & 32" cooling fans back in the late 80's plus depending on how many blades it has puts a real strain on the fan clutches/friction material. Those fans drag 25 to 30 horse power at running speed 1500 rpm. The torque it takes to engage even at idle is a tremendous drag on belts and friction disc. The other pulleys do wear and get polished from dust and will cause slippage and a squeal on start up. Serpentine belts can be the worst for it.
yes you can hear the solenoid engage. That’s mounted on the firewall. This is coming from the clutch itself at front of engine. It’s a squeak from clutch itself. Looking for someone that has experience on rebuilding these clutches that knows how they work and what is causing this in the clutch. I run with 2 other guys with same exact setup. There’s engage nicely and all you hear is the air solenoid on firewall.
You could do a Horton master kit or a Kaiser Premium depending what it is. If you don’t feel comfortable rebuilding it, Then it will be less expensive and provide a a much higher success rate to just purchase a new one. Measure belt groove wear in the pulleys and replace the worn ones. Don’t know if it’s v-belt or serpentine. If serpentine, The belt tensioner is worn out. They are always worn out. So are the idlers.
Have installed many many kits through the years along with complete rebuilt units. And the truth is some squeal and some don't right from the git-go. Kit Masters makes most of the kits. Your friends don't make noise right now but in time. Is the spokes in your steering wheel setting exactly straight with the dash? Either the friction material is glazed-hard as a rock or the solenoid is slow to put full pressure to hub.
One of the trucks i work on does the same thing and it drives the owner nuts. I wish there was a fix for it.
Just money. Money can fix it. Trucks eat money.
Truck engines, especially late model high torque-low rpm torque curve engines play hell with belt accessory drives. Every time the engine fires the crank twists a little and that is directly transferred to the accessory drive. The OEM builds the components as light as possible and it all wears out fast. Especially in dirt. All of it wears out fast and is stupid expensive to repair and function like new
Coaldust, If you keep spewing profanities disguised as facts you will be banned!! Those last two posts couldn't be more correct my friend!!
Give https://kit-masters.com/support/tech support a call and see what they can set you up with