A)
If the driveshaft is not turning;
when the engine is running, AND the trans is in gear,
THEN: the crank and the driveshaft are NOT connected.
It's just that simple.
1) The easiest answer is that there is a shifter to slider issue. Saying it shifts and it actually shifting may not be the same. I'm hearing "the shifter is moving". But that does not prove the forks are following. I already mentioned how to check and PROVE the trans.
2) The next easiest answer would be that the problem is in the T.O. system, but you talked about that and I agree with what you said about it.
3) Next would be the clutch,but I have no idea how a clutch could do what you describe. Even if the clutch disc was in backwards, it would not slip. Instead, it would not release. So I seriously doubt you have a clutch issue, unless; you forgot to put it in, you tore it up, or the center hole is NOT for your trans which should probably be a 1x23 input gear.........................
B) But if the driveshaft does turn; with the engine running, AND, a gear selected; but the car will not move; THEN the problem is in the rearend. And so, there are just two options;
1) the easy answer is that the axles are too short, or
2) something in the guts is not connected to the R&P; this could be due to parts are assembled wrong, broken, or missing; or the crosspin fell out, which I don't think is physically possible if it is in one piece.
Now, something you said is bothering me. You said;
While off the ground wheels turn and drive shaft turns but seems very tight. It almost feels like something is binding up like the e brake is on but I can push it around.
Normally , I would say that this is NOT normal. But if the driveshaft is installed, then; when you spin the tires by hand, you are also spinning the mainshaft in the trans. And normally this is not too big a deal.
But if the trans is also in a gear, then you are also spinning all the gears, including the input gear and the clutch disc if the clutch pedal is down, or the disc is slipping. But if the clutch is clamping the disc, then it should be impossible to turn a tire with a working SureGrip. But with an open diff, turning one tire will turn the other tire in the opposite direction.
So this gives you a diagnostic tool.
You said;
While off the ground wheels turn and drive shaft turns but seems very tight.
But you didn't say if the trans was in Neutral or if it was in a gear. So; shift the trans into Fourth gear,(the easiest to spin, from the diff.) and see what happens. If you can still spin the driveshaft, then; either the trans is not actually in 4th gear, or it is broken; or the clutch is slipping.
But if the driveshaft no longer spins while the tire does,(and the other tire does not reverse rotate, then the problem is in the differential.
Try the other gears, and here's why;
If one fork is broken, or not internally engaged with the lever, and is thusly stuck in a gear; but the other fork is working fine, then it is possible to engage two gears at once. Normally, this will stall the engine at idle when you let out the clutch. The shifter will still work normally.
And here is a wildcard;
If the shifter and the external shift levers are not matched, or if you have mis-adjusted shift stops, then it could be possible to shift all the gears by the shifter, yet the sliders might not travel far enough to engage a gear.
Ok that's all I can think of.
Oh wait;
Back in the 80s I was a transmission rebuilder for a company that has now become a big deal. Transmissions came to me in shopping carts, fully disassembled and fresh out of the parts washers. Along the wall beside me I had thousands of good used parts, for every domestic manufactures you could think of. And among them, dozens of A230 sliders, but usually no used A833 sliders. So I got the bright idea to try the A230 sliders in the A833.
They physically fit. But as I recall, the experiment failed. I cannot recall the why of it. The sliders in one of those two is coded by a circumferential groove, but I don't recall anymore which one. Maybe someone else will chime in.
BTW
if the trans sidecover is correctly assembled, then, you cannot select two gears at once unless a fork is busted. So you cannot use it for a diagnostic tool.
But you can remove the cover, and manually shift the sliders to engage two gears at once. In this way you can lock the driveshaft to test the rearend. Do not try to start the engine because the only neutral you have is the clutch, and if it does not disengage, IDK what will happen.
To test the clutch while the trans is locked in two gears; you can attempt to rotate the crank by the bolt retaining the balancer.
If you try this;
be advised
that it is possible to overshift the sliders, and have the struts pop out. And this creates a bit of panic the first time it happens. If the trans is in two gears, it will be extremely difficult to rehome them. So the best advice I can give you, is DON'T DO IT, overshift I mean. Leave about 1/8th inch between the slider and the nearest gear and do not select Direct Fourth.
Also, with the trans installed it will be extremely difficult to rehome the struts of even just one overshifted slider, because of the lack of working space and the sightlines. I have done it; but on a 4-post hoist, my record for pulling an A833 with a GVod behind it and dropping the dual 3" exhaust...... is 17 minutes, so I might spend more than that trying to rehome the struts in-situe.
Ok so, once again,
happy HotRodding ...... lol
