I have a 86' F150 that has a 302 and a 4 speed. When I press on the clutch going to change gears or to even just start the engine it will squeal but once its started and i have let off the clutch it stops. I replaced the slave cylinder a while back in hopes of it to stop the squeals. But when i crawled under to check the tranny fluid it had a mix of Automatic trans. and Gear oil in there and was thinner than burnt motor oil. Also will this truck be able to pull a 16' trailer with 5 4'x5' 900# round hay bales? Thanks Nick

 

Maybe a throw-out bearing??? I was told that is what went out on my ranger. It would squeel when the clutch was depressed. my brother fixed it and the squeel went away.

 

Which 4 speed?

Get the code off the door sticker and look it up in the sticky.

A squeal when pressing the pedal with the engine off could be a throwout bearing, slave cylinder, master cylinder, or pedal linkage. Squealing while the engine is running and the pedal is NOT moving is the throwout bearing or pilot shaft bushing.