My 70 M-20 has developed a new habit of popping out of fourth gear when applying the brakes about half of the time. I rebuilt the trans about 5K miles, 25 years ago with new synchro and bearings etc. I am concerned there is wear on the input gear that is causing this. Not looking forward to dropping the trans after just installing the new 461 6 months ago. I installed a shorter 3/4 lever and made sure the shifter bump stops were correct, and they are. I even removed the bump stop thinking it was not fully engaging the gear, but seems to have full travel.
Does anyone have any ideas if there is something else I can check before pulling the trans?
My M20 used to do the exact same thing in third. Coasting on compression in third it would pop out. I got used to keeping my hand on the shifter when going downhill in third. They told me it was a lip on the edge of the gear that wears off and allows it to slip out. Don't know if that's true or not. Just what I was told.
I drove the Bird to the local Muncie Guru (Jet Boat Bill) yesterday for him to take a drive and what his thoughts are. It is most likely worn out sliders. He will rebuild the trans and use new Torque Lock sliders to lock the trans into gear. Not looking forward to dropping the trans after installing the new 461 6 months ago.
BTW, He really enjoyed the torque of the 461. Said it accelerated faster than his SBC trike!