Hope someone can help me remember if I'm missing something.

I'm rebuilding a 1976 A-833OD gearbox. New synchros and bearings are all indexed and mounted properly with the gears on each of the shafts. Looks beautiful.

I put the countershaft gear cluster (and bearings) in the case first but didn't install the countershaft so I could roll them to one side when installing the main shaft/drive pinion assemblies. When I did that I couldn't get the countershaft washers to line up properly (the big end ones that "bush" the countershaft gear cluster), so I tried to put the countershaft in place first then put the mainshaft into place. Unfortunately I couldn't get the mainshaft all the way into the case because there isn't enough room to fit the 'clutch sleeve' (for the pinion gear/OD gear combo) into place.

I remember helping my grandfather rebuild one of these in 1985, but I don't remember it being this difficult.

What is the best order to do place these two items? (Factory manual didn't help much here).

Thanks in advance for any advice.

-DusterIdiot


res0aus2@verizon.net

-DusterIdiot,

I will run through the "tricks" I know. One of the first questions is if you have the gearbox on its side or standing on end. I have a 1 inch hole drilled through my work bench because you *need* this thing standing up on its "face" with the input shaft through the hole and its rear main case "butthole" in the air. Position the side cover opening so you can look inside easily.

Next, take a good look at the end of that main shaft. You should find a nice big smooth 45º chamfer (angle) at the tip. Some of these can be rough or small so I recommend that you grind on this area a little so it is more of a smooth radius. Doing this prevents "knocking-down" the needle bearings as the shaft slips in.

I have had good success installing the mainshaft assy. with the counter shaft already installed in position. To do this, the reverse "idler gear" must be centered on the middle of its small shaft. You also need to "hang" that 3-4th clutch sleeve (sliding collar) right at the end of it's travel. This is tricky, I put some real sticky silicon grease on it to *try* to keep it from falling off when the whole assy. is hanging upside-down, on the way into the case. Don't get too "pissed" if the collar falls off and the 3 toggles fly around (they are under spring load).

OK, "Indexing" is a key point, but where, what, how?? On the sliding collar, put a paint mark to show where the toggles are. If you look close, you may find a factory paint mark already there. You need to know where these toggles are because you can not see them with the collar pulled forward. Also mark the front synchro ring, out at its teeth, showing where its block / notches are (where the toggles fit in). Basically you need to know where these locations are because the collar blocks your view when it is pulled forward. (And yes, the more forward the collar is, the easier the tranny will go together.

OK, now the fun starts and grandpa had the right idea. Get another person to help during this next step. It is a "4 hand job".

Now you need to lower 50 pounds of gear/shaft /tailhousing assembly into the case. Before you start, be sure the tailshaft gasket is in place. (I put a little glue on it to keep it in position.) Now slowly lower the tailshaft/ mainshaft assy. in, snake around the reverse idler and countershaft gears. I shoot to rest the mainshaft "nose" on the edge of the input shaft "cup" as a "first stop" to give my arms a rest and check my "indexing". If the collar slips-off, pull the assy. back out and reset the collar & toggles.

Position the synchro and collar so the paint marks are lined up. Move in to stick the mainshaft nose into the needle bearings, as your assistant makes sure all the other gear cogs "mesh" with the countershaft teeth. (Rotate the cogs on the mainshaft, don't turn the input / countershaft because that throws off your paint mark alignment.)
If you get all this stuff lined-up correctly, the whole assy. just "plops-together", with-out much "fan-fair", just like you saw grandpa do it. (Sounds like he knew the tricks.)

Sounds like a lot, but it really isn't, go give it a try and let us know how you do.
DD

Thanks Doc. The tranny is together and looks great
(I'll get to mounting the sideplate tomorrow).
If I'm ever in your area I owe you a dinner from saving me some frustration and headaches.

Anywho...
Some of the problems of putting this model together were compounded by an interesting development (see picture). I found I grabbed the countershaft cluster from my other tranny and it didn't match the one I needed to put into it.
In the pic, the set I used on the left had an 'N' punched into the top of the set, she has 22 teeth on the drive pinion and 33 teeth on the cluster (standard OD set 1975+). The set on the right has 36 teeth and 24 on the drive pinion. Do you know where this set came from? (I can't find any reference to it in any Mopar book I have).

Just an FYI on the steps I took to assemble the OD tranny as they were a bit different than prescribed. (Might help the next guy doing this too, as these are getting to be popular.) Assuming the mainshaft is all assembled and indexed, and the reverse gear idler set has been removed:

1) Assemble countershaft set (needle bearings and washers too). Cut off broomhandle to 1/4" less than the width of the countershaft gear cluster and insert into cluster (keeps needles and washers from going wacky).
2) Insert countershaft end washers into keyed slots and stick them there with gob of sticky grease.
3) Iinsert countershaft gear cluster from butt side and leave loose but keep stable with one hand if you change the case's direction.
4) Tip case on face, then insert mainshaft/tailshaft assembly into the butt (don't forget the gasket). Twist tailshaft until it clears the countershaft hole then insert 1 bolt to hold it.
5) With a helper (unless you are very butch):
Carefully tilt case so the tailshaft points down.
Put in last synchro for OD gear set/pinion.
6) Gently drive in the drive pinion (with new needle bearings) lining up the nose of the mainshaft to the back of the drive pinion. Should mate up with nary a problem.
7) Using the 1" hole drilled into the bench, stick tranny face down (drive shaft into 1"hole).
Line up countershaft gear cluster with holes in case, broomstick will start to come out if aligned correctly. Grease up and drive countershaft in from backside. Broom stick falls out, leaving needle bearings intact countershaft installed (make sure to line up woodruff key in shaft and case).
9) Put tranny on its belly. Remove tailshaft bolt.
Twist tailshaft 30 degrees to clear reverse idler gear/selector shaft hole.
10) Insert reverse lever shaft and fork and gear.
Have helper hole while driving greased shaft and woodruff key home.

Steps 4 and 5 could be swapped: pinion first then put in the mainshaft.
The only reason this is done is there is no clearance in the case once the countershaft is installed, the clutch sleeve for direct/o.d. wedges against the top of the case and the countershaft gears. (Probably much easier for the close ratio tranny).

Hope my headache helps someone else with a post 75 OD tranny.

Thanks again Doc you are truly the man.

-DusterIdiot



res0aus2@verizon.net