A833 OD shift mechanism
. It James worse when running and driving
Hang on Johnny, we'll figure this out.
In this case, when you say jams, there are several ways to define this jamming.
First, lets talk about a regular H-pattern shifter.
The most common jamming is that when you pull the stick out of say Second gear heading for third gear, the shift-gate has NOT returned to neutral. The only cause for this that I have ever found is a loose nut on the 1-2 shift lever that is bolted to the trans. In this case, the 1-2 shift rod can end up hanging several degrees outside of the neutral gate, and to get to third or fourth gear on the other side of the gate, you gotta wrestle with the shifter. Eventually the gate lines up, and you can get thru it.
This cannot be fixed by aligning the gate and just tightening the loose nut; it will happen again. This is a common occurrence when there is wear between the lever and it's pin. The cure is to fill that cavity with loc-tite-red, as explained previously.
Another thing that can hang you up is those goofy QD curly rod retainers. I throw those out install washers to zero-clearance and then install cotter-pins. At the case, the curly thingies can stay.
Another thing that can hang you up is a dirty shift mechanism, or one that has been greased! Your shifter has to be clean, dry, not oiled and especially, not greased. The guts of that thing are like a Swiss-Watch. When you select First gear, you hammer the shifter towards your big right leg ( Ok my big right leg). This causes a precision "bolt" to move from it's neutral position, thru a thin aligning shim, and into the lever that will then be able to engage the the shift rods to do their trick. But that "bolt", has to stop in the exact right position, in it's left/right travels, and to that end, there is another thin stopping shim.
Now when you pull the stick out of Second, going to Third, that "bolt" is now spring-loaded with a powerfull spring. and so, as it comes to the shift window, the spring is supposed to fire that bolt thru the gate towards the 3-4 lever. As it does so, it hits a stopper shim on the other side, which aligns it to the 3-4 lever, and now it is ready to engage Third (or Fourth). If all the shims and levers are in alignment, and the "bolt" is energized, this will happen all by itself with No help from the operator and in an instant. If this device/mechanism is assembled correctly, aligned, and the bolt-spring has the power it left the factory with, then there is NO WAY for this device to ever hang up. I have been using the same shifter since the 70s with only ever one cleaning, which I did just because. I'll guess that this shifter has over 300,000 miles on it. It never misses.
Ok so what keeps the shims aligned (not the levers) ? Well, they are sorta rippled, and when you tighten that front bolt, external to the mechanism (I think it's on the front; and some don't have it) this causes the shims to expand ever so slightly which then jams them into posoition. If your mechanism does not have that external bolt, then this will be done with the lower of the two mounting bolts.
Now, in some shifters, those shims are NOT rippled but are flat. However, they are thicker and sturdier, and don't make any trouble.
I'm gonna go out on a limb and say that your shifter is NOT the problem.
Next, we come to a ***** of a thing which is the reverse interlock. It can happen that it rubs on the 1-2 lever. Which them makes trouble when coming out of Second going thru the gate. In this case the 1-2 shift fork may not come exactly back to the neutral detent on the pre-1971 covers. There has just enough slack in those for this to happen, and when it does, the 1-2 rod does not normalize back at the shifter, which them hangs the "bolt" up from scooting thru the gate.
The cure for this is, usually, to just loosen the side cover and force it up, then tighten her dowm again. But you have to prove that this has worked by disconnecting ALL the shift rods, leaving the levers on the nutted-pins, and then selecting reverse. if reverse snicks in and out, without undue force; and with reverse NOT engaged, the 1-2 lever snicks in and out without strain, then she's ready to go.
With the trans assembled with the parts it left the factory with, this is rarely an issue. Usually this is only an issue if the cover was changed or the internal reverse lever was, then it is possible for that interlock to be too tight. The cure is replace the internal lever with one that has more clearance, or to modify the interlock that you have, or to just raise the cover.
I cannot think of anything else right now, and it's long past dinner, so, I gotta go, lol.
But before I do, I want to repeat, most if not all shifting problems of this sort, stem from the levers moving under the nuts. Red loc-tite them and maybe your problems will go away.