A883 2nd & 3rd question

How long has it been grinding on shifts? Upshifts only? or downshifts too? Does it jump out mostly with the power on? or on decel too? Only on 2nd and 3rd?
Do the linkage tests first.

-If it ends up being the clutch teeth on the gears,(The most likely), Ive got some tips for you.
-The A-833 gears do an odd thing. They like to wear clutch teeth on the decel (coast)side of only 6 teeth; 3 side by side,on one side and 3 more,side by side, at 180* on the other side. The cheap,easy,simple,fix is to grind those 6 clutch teeth back to where they no longer contact the slider(synchronizer) teeth.Six different teeth will come into play.Then angle-cut the front sides(drive sides) of any/all bad drive surfaces. Then do the same on the synchronizer teeth. Then sharpen all the worn teeth. This will restore all the surfaces to working condition.
-You can use a die-grinder for this, but I have never found a carbide bit to successfully do this. It requires a little grinder disc, about 1/8 or 3/64 thick and 5/8 to 7/8 in diameter mounted on a small mandrel for the clutch teeth, and a smaller one for the slider teeth. You may need several discs in total.Once you get the hang of it you will be grinding all your friends gears too.
-I also cut oil channels up the faces of 3 of the the cones(skipping 1st).I cut three on each, about equidistant from eachother.I cut them from the clutch teeth to the top of the cone. I make then about 1/8 to 3/16 wide and 1/16 to 3/32 deep. I do this with a very small disc so that it leaves a nicely bottom-rounded channel like a river, not like a tire-rut. This provides a place for the gearoil to escape and speeds up the shifts. Do not use synthetic. Its way too slippery, and slows the shifts.
-Additionally, you should deglaze the polished cones, so the brass bites hard on them.This is usually done on a lathe, with emery-cloth roll and a suitable backing-strap like a file.I use 100grit, but you might want to start with 180 to 220 as a newbe. The brass should lock on with only a tiny bit of pressure.Almost by its own weight.I bias the polish on the gears so they bite best in the upshift direction, except 1st, which I bias-polish for downshifts.
I have done hundreds, maybe thousands of trannys like this.(not all A-833s, but every major make and trucks too).
Now, replace all the worn brass rings, and you will be good for many more years. Some times/lots of times, when you buy a 4-pac of new brass rings not all of them are any good. If you find one or more that dont bite, heres what you do; A)Either re-use an old one(pick one that sits high on the cone and bites), or B) fix the bad one. The fix is actually pretty easy.The brass is usually oval from a drop.Oval rings dont bite, unless you press down hard. You dont want that.So stick the bad ring on the input gear(usually the least worn). Just set it on there gently.Figure out in which direction it rocks. Mark the pivot points with a sharpie.Now you will want to squeeze it round. So those Sharpie marks will need to move away from the cone.No you cant squeeze it using human power.As a newbe I suggest you use a vise.Put it in there, correctly orienting it, and put a little squeeze on it. Make a mental note of where the vise handle ended up at. You may need to do this several times, using more pressure each time until you get it.Now fit it up again and check the bite. Repeat as often as necessary to get bite/no rock.If youre scared to try this, consider that a rocking ring is garbage anyway.It could happen that you bend it too far and it rocks in a new direction and the Sharpie marks are no longer correct. Make new marks and start over. Now, I dont use this method, but I think its best that a newbe does, cause its the least likely to destroy that ring. And if you really want to know I use a hammer.But remember, Ive built thousands of manual transmissions.
-Some guys rant about worn struts.I say phoey to that. Some of my struts are almost as old as Methusela.Just remove the sharp edges and reuse them. However the energizer springs are more particular. Stretch them out a good half inch and gently reinstall. Sometimes I use more than one per side.Put the best biting brass on 2nd and 3rd, the poorest on 1st.Remember 1st needs to bite in the downshift direction.
-Make sure the snapring on the input gear bearing is the right one.Install the assembled input gear into the retainer and make sure the snapring drops in and is not standing proud above the recess in the retainer. The blue ones that come with the bearings are usually wrong(too big an OD and often too thick).I would say always, but sure as heck somebody, somewhere has received a bearing with a snapring that actually fit and then I would be a liar, and liars are on the list of people that cant get into heaven.
-I have been doing these mods,as well as others on my personal rides, and many friends rides, since the 70s. My trannies shift sweet at any/all rpms. Mine bangs in at 7200rpm, regularly. It has a few other mods.
Ok then, getrdone. PS, hello TB