My 1984 f150 with 4 speed granny is freezing up when it sits for a few days and when I drive it it shifts good throufh all the gears but grinds when going in reverse and 1st im thinking flywheel or input bearing any other suggestions thanks. ..

 

You know you have to be at a stop to engage 1st n reverse i assume. 1st on a np435 granny is unsyncronized. And reverse is unsyncro too but, well its reverse.

Now id bet your clutch system is the culprit. And being as you say its worse after a couple days of setting id put my wager on the hydraulic system. Check your fluid level, maybe bleed it a bit. See if that helps (just like bleedin brakes). If it dont you may be getting to where you gotta change the clutch slave cylinder.

 

X2 on what Jayzdaddy said.
If it has a hydro slave clyinder, you will need to get the flywheel resurfaced for smooth clutch engagement.
Ask the machine shop how much they took off and get a shim to put in between the crank and flywheel to get full pedal travel back.

 

Thanks for the info it has a external slave cylinder I'm going to bleed the clutch then try to change the slave cylinder see if that works before I drop the tranny