Well on the 3-4 you may not have to completely tear it down. I've never done this but I think it's possible to do it.
If you secure the trans on the bench nose down,( I have a hole in the bench to allow this) then remove the side-cover and back out the 6 bolts a scosh over 1/4 inch. With a long prybar carefully pry second gear up about a quarter of an inch and slide in, at least 3 same sized spacers, between the tail and the mainbox, at 120degrees apart. Lift Carefully, cuz if you go too far the pilot rollers will fall into the input gear cavity and then it's game-over.Then tighten a couple of those back bolts at about 180degrees apart.
Next, reposition the trans laying it down, cover side up and prop up the tail until it is close to level.
Then go find that broken strut,remove it, and push the slider to the rear.
Now installing the replacement strut is gonna be tricky; you have to re-engage the energizer springs below it. Both of them;one on each side of the hub. What I would try is to pull the frontmost spring forward far enough to squeeze the strut in between it and the slid-to-the-rear slider. Then as the strut slides in there, re-engage the spring and continue to push the strut all the way in. Then slide the slider forward and pop the rear spring in. Then do a visual recheck.Properly installed, you will not be able to see the springs. If you happen to rotate the spring there is a chance that the other end popped off the strut. If you see a hook pointing up at you on that spring, it goes into the cavity on the back of the strut. If you cannot get it in there then the other end is jammed against the side of a strut and you will have to go fix that first,lol.Finally re-center the slider.
At some point, one or both of the other two struts may pop out of the slider; don't panic.Just continue with the spring install. After you get that strut installed; just push one of those wayward struts down and under the slider while keeping some pressure on the slider to slide over it. Then keeping the slider there, pop the remaining ones in, and center the slider. Then, being careful to not overshift it, shift the slider back and forth a couple of times to prove the operation was successful.
Like I said,I have never tried this with the M/S still in the case, although I have done it many times with just the M/S on the bench.
Now to continue; Make sure both sliders are centered on the hubs.Gently stand the trans back up on its nose, so the sliders don't fall down. Back out the bolts previously tightened. Go get that long prybar and as before,raise the tail by jacking second gear, to remove those spacers.Then drop the tail back in.
Now
The reason we use the Long prybar is for control. To control the raising and lowering of the tail, just enough to install the spacers. Those pilot rollers are only about 1/2 inch long, maybe a tad more. If you raise the rear too far the needles COULD fall into that cavity. Could; not, will. This is also why the operation has to be done with the M/S vertical, so the rollers remain standing on the ledge inside the input gear.So be careful.
Ok, back to the finish line.
With the tail now back on the maincase, be sure it is fully down flat. If one roller fell out of position, it will fit in the cavity, but IIRC two rollers will not fit.So if the tail sits flat, then there is a very good chance that all the rollers are still where they belong, so tighten up all the bolts. But if the tail does not sit flat, then it's game over; the beast will have to come apart.
So assuming a successful install, reposition the box, cover up, ensure the sliders are in neutral, and slap it all back together. Then bench test it and you're good to go.
During bench testing, one of the shafts should be rotating; either the M/S or the input gear. This will help to make it possible for the slider to find the clutching teeth on the individual gears.If you run into resistance don't force it, just go to a different gear and come back to the sticky one later.
