So was driving the car pretty hard today and actually blew a couple shifts which was kinda weird, doesn't normally happen. Anyways everything seemed fine, parked it for a few hrs then went for a drive, very noticeable grind going from 4th to 5th every shift. Seems fine everywhere else. Did I destroy a syncro or something? Should I take it to ford or a good tranny shop, no warrenty left

 

Um... How bad is the grinding sound?

 

It's pretty bad. Makes me not want to use 5th at all.
Stock clutch and shifter

 

Sounds like you blew a synchro. Mine did that but with third. I had 40,000 miles on my car and Ford replaced 1st thru 4th synchros under warranty. When it blew it took the clutch with it. Definitely not a fan of this transmission.

 

If you're out of warranty, a Ford dealer is probably going to charge a lot more than a good transmission shop

 

5th gear is a known weak spot in the box. You have indeed probably taken a couple teeth off the synchro ring, or rounded them off at least. Can you slow the shift down slightly and it get better?

 

when you "blew" your shifts, what gears were you shifting from/to?

 

Think it was 1st-2nd and 2nd-3rd, can't remember exactly.

 

Only way it will go in without grinding is extremely gentle and low rpm, can't stop the grinding at hwy speeds.
I'm thinking of just going with the Tremec Magnum xl trans I've been reading about. Expensive but hopefully will last. Any opinions on it?