A833OD Binding in 4th Gear

hey everybody, how can I help?

Lemmee start by saying this;
Over-shifting, on a correctly assembled A833, can only be caused by a failure of the interlock mechanism, the wrong front slider is installed, or a fork is bent. Since the later covers have this most excellent interlock mech, that cannot be it, lol. Which leaves, a bent fork/wrong slider, or the trans is not assembled correctly.
As to the wrong slider; the A230 slider will install onto the A833 3-4 hub and seemingly fit perfect. But I don't use them because I once had a warranty issue with...... overshifting.... lol. You can recognize the A230 slider by the one machined groove on it next to the fork channel.
The way the A833 is designed, engagement of direct gear can be iffy.
If the tailpiece, which carries the geartrain, is too far back (away from the input gear), the fork will naturally overshift. This can only happen in one of two ways, either the wrong rear bearing has been installed, or there is too much gasket in there. This almost never happens.
But more commonly, the input gear is not far enough into the box. This can happen if the wrong front snapring has been installed on the front bearing (way too thick) which usually breaks the retainer on installation, but if you stack a bunch of gaskets in there, you might get away with it. That large front snapring is specific to the A833, in that it is thinner and of a smaller outter diameter, so it fits into the retainer properly.

Ok so how can you tell which it is?
Easy, leave the box assembled.
Pull the cover off and remove the 1-2 fork. Remove and save the gasket.
Grab the 3-4 fork and lay it on a flat surface. install spacers on the wear-pads to elevate the fork off the table. Measure the height of the interloc pin, then flip the fork over and measure it again. The measurements should be the same. If they are significantly different, the fork is bent, and should be replaced. But if the bend is minor I re-install it oriented so that the slider will travel a hair further towards the input gear.
Find the two longer screws that have the longer shoulders on them. These have to be installed in specific locations namely, the two holes that are deep enough to receive them which are about half-way up the front and rear sides; go find the matching holes.
Ok, now install the cover with those bolts in the correct location, snug it down and shift her into direct. Spin her over a few times, Then remove the two screws, and pull the cover straight up, fork and all. The slider better have shifted well forward, and the brass is well encased. Make a note or take a picture.
next, put everything back into neutral, install the cover, shift into the other gear, be it Third or overdrive, spin her over, then pop the cover off again. Check the position of the slider. The brass ring should be well inside the slider, take a picture. Theoretically, the slider should move an equal amount in both directions but it never and I mean NEVER does.
So, on the other side, away from the now selected gear, the brass HAS to be held captive on the struts. and the struts have to be held firmly in their recesses in the slider, by those energizer springs. If there is a lotta monkey motion there, it's gotta be fixed first.
But before you take the trans apart, you might as well check to see how far the struts are into the non-selected input gear. If they are barely hanging on, you will have trouble, do not try to run it like that, cuz sooner or later she will get stuck in overdrive.

Ok so now, with the synchronizer assembly on the bench, slide the slider back and forth on the hub, but not far enough to cause the struts to climb up out of their recesses. This should go smoothly. Next make the struts climb. This should take a very significant amount of force to get the strut out of the recess. If it does not, then you will be able to physically move the slider by the shifter, from the cab, BEFORE the brass has performed it's function of Synchronization, and you will grind the clutching teeth together, even tho there may be nothing wrong with them. What I do is remove those springs, and both together, I stretch them out quite a bit, until they keep their new shape, then reassemble them and re judge the force to climb up out of the recesses. You cannot with just two springs, create too much force, so just crank it up.
While the springs are out, inspect the struts for wear, at the place where they climb out of the recesses. nobody cares about the faces, just the ramps. If there is significant wear this will delay synchronization, not a big deal to a cruiser, and not a big deal to me cuz I easily overpower those parts with my street slick-shifted box, lol. But it can make normal driving a bit of a pita. Ok so that takes care of the Synchronizer. As to the points on the clutch teeth, yeah it's nice to look at if they are all nice and sharp, but in practice it's not that big a deal and they can be really beat up on all gears except first, and still function perfectly fine. Sharp teeth can help you find first gear atta stop.
Moving on;
the brass rings have to sit HIGH up on the brake-cones, away from the clutch teeth; especially on Direct, because it always ends up being waaay over there. If the brass moves too close to the clutch teeth, it will simultaneously move away from the struts. I always check every used ring and install the highest-sitting one on direct, just to prevent this. However, every ring you check has to also grab the brake and lock-on with very little effort. If you get a high-sitting one that does not lock, it is probably bent. The normal thing to do is throw it away...... but if you know me.... I straighten them out and stick that one on First gear, cuz I hate it when that first gear locks on too easy, and the points butt up, and now it won't go into gear until I shift back into neutral and start over, I really hate that, lol.
Ok so, now we got the best parts on direct, including the correct front snapring and the thin retainer gasket forcing it all to the rear of the box.
The next check is to make sure the rear bearing is tight in the tail house and tight on the mainshaft. If it wobbles back and forth, that is bad news. The mainshaft has got to be as far forward as possible, to keep that frontmost brass on the struts. If yours moves more than say .020 (cuz they're NEVER tight, lol, I would find out why and fix it. Check the bearing dimensions against their specs first. Bearings a precision manufactured so you shouldn't have an issue, yet the Chinese hate Americans, so you never know. Do what you can to move that M/S forward as far as it goes.
Next is the rear gasket. Use the thinnest one you got, Do not make one out of thick stock, The closer to .020 or less the better.
And that brings us to reassembly, lol. So get that done, then see what has happened, by again performing the shift test.
This time, take a small screwdriver, and with the trans in overdrive, shifted there by the cover, attempt to push the direct brass up the brake cone, pulling it out of strut engagement. Over 100,000 miles, that brass might wear .020, so you gotta have that much strut engagement, plus I'll guess at least .020 more to ensure it stays on the struts. I don't know if there is a spec for this, so Ima gonna arbitrarily gross this up to 1/16th inch.
Finally, the more worn that the overdrive brass is, the further it will move towards the overdrive clutching teeth, which will simultaneously allow the struts to create additional room for the Direct brass to disengage.
However,
The fork is always in charge of where the slider is supposed to be; so if the pads on the shift fork are worn, that's bad news. What I do is braze some hard brass on there, all on the direct side, then file it flat, so that it pushes the slider as far forward as possible. I mean we're only talking 20 or 30 thou, depending how worn it was, but if you start adding up all the numbers, it can get to that minimum 1/16th inch pretty quick.
Btw new brass does not mean better. There was a time you couldn't give me new brass, cuz a package of four might have four bent ones in it. doggone it. I haven't bought new brass since the 80s, so maybe it's better now... IDK.
>well that's about it I guess,
Happy HotRodding

Oh wait, I forgot; as to the struts, the ends of them where they push on the brass has got to be intact and as unworn as possible. Sometimes, if the brass has spun, it wipes the ends off; which is about the worst news ever, I mean to your A833, lol
And BTW, from the three pics I see, those parts look excellent.
As to the cluster washers, those guys can take a real beating, ending up chock full of metal and still hanging on. But, if they spin, they're gonna leave a mess behind; so keep the end-play under control.