My 1983 Diesel wagon with an M46 trans was getting harder and harder to shift into first. Now its impossible. All other gears go in easily including reverse, engine on or off. I took some play out of the clutch cable adjuster and topped the trans off with ATF but no change. Will I have to open the trans or could it be a linkage problem fixable from the outside?

 

Is the reverse lock out gate in the correct position? If it's too far to the right and/or shift linkage bushings and cage bushing are worn out/missing - that can prevent the shifter from going far enough to the left.

Can you get it into first by lifting the reverse lockout and not push as far to the left for reverse?

 

I tried pulling the reverse lockout and moving the shifter in various positions but it will not move forward into first.

I am able to get the lever into first by starting the engine, pushing in the clutch, pushing on the lever which won't budge, then slowly letting out the clutch until grinding is just heard. I then push the clutch back in while continuing to push the lever forward with very light force, and it slides right into first with no grinding or effort.