Factory 73 Top Loader Falling Out of First

As the title suggests. I have a recently acquired Q Code '73 with factory 4 speed and am finding that whilst shifts are slick as can be, at a stop, the transmission will quickly "idle" its way from first gear to neutral. My wife is becoming unnerved as she keeps it rolling whilst I am away. I will be home mid-March and throw the car up on blocks to give it its first good look and I have done a bit of searching but thought I would ask here too.

It could be several things. Easiest first, check linkage adjustment, If the shifter has stops, check adjustment. Make sure the bolts securing the transmission to the bell housing and the bell housing to the block are tight. After that you are inside the transmission. It could be bent/worn shift fork, shift rail, detent ball/spring, synchronizer or missing cir clip. Sources for parts and expert advice; Dan Williams, David Kee, Mark at top loader heaven. Let us know what you find.

Chuck

Spot-On, Chuck! ::thumb::

I've found that it's rarely something simple, and usually winds up being synchronizers, depending on the mileage... but in my experience, that's more with issues going into gear and popping out while under a load.

But always start with the simple stuff first, EdM... as Chuck pointed out.

Three things come to mind.

Shift linkage adjustment not fully engaging 1st gear.

Bent shifting fork not allowing 1st gear to fully engage.

Weak detent spring not keeping gear engaged. Along this same line, it could be the detent notch is too shallow, I had this porblem on a transmission many years ago.

Geez, the first thing that came to my feeble mind is that the shift rods are out of adjustment.

I had a 1974 Porsche 914 that had this same exact issue. I could get it into gear, but as soon as I tried to let out the clutch, it would pop into neutral...

The car ended up in flames at the shop... I've been trying to pick up the pieces of my broken life ever since...

So while stopped, you can put it in first fine, but if you take your hand off of the shifter it will pop back into neutral?

Could it be something as weird as the shifter boot?

Yes, that is what it does. Appreciate all of the pointers. The PO had the transmission rebuilt 5K ago so hoping it is not internal issue.