Okay, first time posting here. I bought my first truck about a year ago, 1994 f-150 XLT, 5.0 motor, 5 speed transmission, 4x4, 4.5 inch lift. Since buying the truck I have noticed a very odd squeak noise getting worse over time. It happens under a few different circumstances. If I push the clutch in quickly, especially with a big load difference between the motor speed and transmission speed, such as when starting off, or towing etc. the truck makes a very loud chirp noise. It also does it very often, pretty much 100% of the time when I am slowly inching forward in a drive-thru, especially when the cashier is a hot chick lol. I am inclined to believe that it is actually nothing to do with the clutch or any transmission components related to that because I have noticed that when the clutch is all the way out and just cruising with no throttle in a low gear, if I feather the gas and make the truck jump back and forth, it will make the same squeak. From my knowledge that would eliminate the slave cylinder since the slave cylinder has done everything it is made to do when the clutch is fully out and attached to the motor. One time it made a similar noise while turned off and parked, I cant remember if the truck was in gear or if the brake was on or both, but I was pushing on the back of the truck as if i was trying to push it down the road. That may have been unrelated though, I haven't been able to replicate that. This made me think the leaf springs were just rubbing or something. So I torqued all the rear suspension bolts and even put some wd40 and axle grease where I could. no change. I ended up changing the universal joints because they eventually went bad and I was excited because I figured that was the source of the problem, seeing as the universal joints are put under load at the same time as the clutch. No change. greased them heavily later, still no change. No motor mounts or transmission mounts are broken. I am very reluctant to try the slave cylinder because it is internal and I genuinely don't think it could be that because of the reasons above. The only time the problem seems to get a little better is when the motor is very hot, but I am not even sure is that correlation is true or just coincidence. Thank you for all your help everyone!

 

Well depending on the quality of the lift, your driveshaft angles may not be optimal. I know my truck gained almost 3 inches when I replaced the rear springs with a set from a 250. And since then, I've been through 2 front u joints on the rear driveshaft, because the angles are too severe. It was noticed when the springs were installed, but I was in denial and pretended it wasn't a problem. I just picked up new (shorter) U bolts so I can pull the factory blocks and just set the springs right on the axle.
If I were you I would actually pull the driveshaft and inspect the joints and move them while feeling for stiffness.

 

Yeah, I mean like I said I already replaced the U joints a couple weeks ago.. No change. Any other ideas?

 

Check for a rear brake that might be out of adjustment, and try spinning the front axles. Maybe one of the hubs is not fully disengaged, this would cause the front driveshaft to spin

 

Okay, cool. And how would you recommend checking for a misaligned brake? Like taking the brake drum all the way apart? Or are you talking about the front brakes? Thanks for your help!

 

Easy way would be to jack the rear up, put on stands, pull tires off and spin the drums. You would hear the noise. Also for the front, just jack up each side and spin the tire while listening.