The original (one year only) 4 speed shifter can be the problem? Brian

 

It had a hurst comp shifter installed in the early 70’s.

 

What did you use for gear oil? GL4 or GL5?

 

GL4 but no idea what came out.

 

Could be internal damage or an improper rebuild, could be the Z-bar linkage needing adjustment, or could be your Hurst shifter needing adjustment. I'd start with new GL4 gear oil and a shifter adjustment, assuming the clutch pedal adjustment was completed per the Ford Factory Service Manual?

https://www.holley.com/blog/post/how_to_adjust_a_hurst_competition_plus_four-speed_shifter/

 

Thanks, I’m pretty sure it’s internal. I’ve replaced all the zbar bushings and rebuilt the pedal shaft with Mustang Steve bearing. Oil is fresh too.
Just really wondering if just rings usually fixes this or if gears and synchros are often needed too.

 

Well I finally pulled the transmission.

Unfortunately the engagement teeth are badly worn on my 2nd gear (upper in pic) so I will need to replace it.

 

Also check the matching synchronizer (AKA slider) that engages the gear teeth for damage when you take the transmission apart.

 

I would