The vehicle: 1985 F150 2WD lwb 300 l6 4sp od

Initially I thought it was just my imagination, but now I think I have a problem of some kind with my clutch. The clutch is generally quite heavy (compared to my car) and of late I've been thinking it's been somewhat light. I assumed this was just my imagination but now sometimes when I release the clutch pedal the pedal releases nearly completely but it stops just beforehand. I can lift lightly from underneath with my foot and it will easily release the rest of the way. The truck seems to shift fine but I'm thinking I must have some kind problem, I just don't know what.

I don't know if this is related, but I also recently started hearing a new rattle which (according to the ear-o-meter) seems to be coming from underneath the driver's seat.

Any thoughts on what I should start looking into first?

 

The noise can be the throw out bearing going bad, and the stiffness of the clutch can be a lack of lube on the shaft the throw out bearing slides on.

 

'80s firewalls were prone to flex, rust and cracking. If it's flexing enough, it will cause a bind in the linkage parts of the set up, or misalignment in the master bore. Either could lead to a stiff clutch and clutch that hangs up.

Have someone look at the firewall as you work the clutch.

 

Bingo!!

 

I hadn't even thought about the firewall flex. Remind me please, where precisely does it usually flex?

 

Since I didn't even think about the firewall flex before you guys mentioned it (thanks btw) I did a bit of reading in this (https://www.ford-trucks.com/forums/1...ll-cracks.html) thread and it stated there are multiple plate sizes to address this. I would really prefer to use the small plate if I can get away with it since it requires far less be removed in order to install it. The part number listed in the thread was E3TZ-7K509-A and I found it a couple of places online under $20. Much better than I expected. I will try looking at the firewall as the thread described tomorrow sometime. I hope the small plate solves my problem.

 

Here are some more pictures:

https://www.ford-trucks.com/forums/1...-cylinder.html

 

I know it's been awhile, but I have the solution so I thought I'd update the information contained herein. Turns out it was a broken pressure plate on a relatively young clutch, about 47000 miles old. The last mechanic to touch the truck before I got it did a bunch of shoddy work including on the clutch. A new clutch, pressure plate and throwout bearing solved the problem. While the tranny was out, my mechanic (I use him when a job is too big to do at my apartment) replaced the oil pan gasket and the rear main seal to address a mean oil leak that recently developed.

Regarding firewall flex, it does flex a little, but not much. A previous owner added a small homemade plate at some point.