Manual Transmission keep jumping out of gear...

[Airstrike]

Currently I have a 3 speed in my 78 CJ7 . I am assuming it is a T-150 . Lately it is diving out of first gear when starting out and sometimes even in 2nd when I let off teh throttle.

Is the synchronizer going bad?.. this is what I am guessing.

Also I am wondering.. if it is bad... is it an easy fix or a nightmare to where a new tranny would be the easiest swap. Been awhile since I did a tranny/transfer swap and I admit I am a bit nervous about it.

Pic of tranny and Transfer Case below... T-150 /Dana 20 I am guessing?
One other wierd thing to note... I had it in about 12 inches of sand and was testing the 4WD... from top to bottom my shifter says 4H, 2H, N 4L. The wierd thing is .. when shifting it around it feels like there is 2 4L selections below N. Am I just losing my mind? Seriously there is 2 distinctive shifting postitons for 4L below N. Any ideas?

Thanks.

 

[mtnwhlr]

Sounds like it is time for a rebuild.

 

[Rollie]

It can be a synchronizer, or it can also be in the top cover. If one of the rails gets broken or if the springs under the balls rust and break they can allow it to jump out of gear.

 

[Saddle Tramp]

Or it could be too much end play, bad motor or transmission mounts, no or bad torque stud, misaligned clutch, as well as other things. I would pull the top off and see what’s up if anything; easy to do through the cover in the floor. If everything looks good check the mounts. With a CJ Dana 20 when in 4L the shifter should be forward almost to the floor .