help please; can't get muncie to shift into 4th gear?

[elky-to-go]

Hi My son and I just finished the auto to 4spd muncie swap on his 79 elky; on first test car on lift; all gears shifted good; went on road test and wasn't able to get it into 4th gear (grinds) came back put it back up onlift backed out hurst shift stop; tried on lift again ok; went out on road test, but still won't go in 4th? any suggestions would be appreciated. thanks John sr. & jr

 

[R/T kota]

are the shifter rods at proper length?
Something binding up around the shifter itself?
Been a while since I had a muncie.

 

[87MonteSS]

Sounds like a bad synchronizer to me. I've blown a number of them on Muncies and Saginaws in my lifetime.

 

[elky-to-go]

can't get into 4th gear

Hi someone said they had similar problem; and added Lucas trans additive and problem went away? anyone heard of this working? thanks Johns'

 

[85 Cutlass Brougham]

There is supposed to be an alignment hole on the shifter that a nail will pass through when everything is in proper alignment. I have never played with a trans without an internal rail shifter, so I am not speaking from experience, just something I read about 10-15 years ago.