Reduction Box Tranny Removal

by Mike Gensler

Anyone out there wanting to remove a tranny from a split-windowed bus? I just did and it wasn't too bad. A manual would have helped a lot (Muir's and Beetle manuals don't cover the redux boxes) and I couldn't have done it without the help of some individuals on the Type2 list. If I had known what to do ahead of time instead of figuring it out as I went, the total time involved would have been 3-4 hours. Not a trivial task, but do-able in an afternoon or evening.


Tools needed:

Go to it:

BEFORE jacking up the bus:

  1. Remove the tranny oil drain plug(s) (17mm allen) and drain the oil into a suitable container and replace the plug.
  2. Remove each of the redux box oil drain plugs and do the same.
  3. Loosen , but do not remove the rear hub nuts. These are big 'ol muthers and can be a little snug sometimes.
  4. Go inside your empy engine compartment and loosen but do not remove the two 27mm bolts that hold the rear tranny carrier in place. DON'T remove them yet!
  5. Remove the clutch cable - its looking you right in the left eye if you're still in your engine compartment.
  6. If you've got a backup light switch on your tranny, unhook the wires from it - I'm not sure about this one because my 58 doesn't have any.
  7. Remove the starter if its still there. You'll have already removed the upper mounting bolt when you removed your engine so you only need to remove the lower (13mm?) nut and any wires that are attached to it.
  8. Slide underneath and remove the 2 15mm (maybe 17mm?) nuts from the front tranny mount and make sure the ground strap is free from the bolt or else you'll tear it when you pull out the tranny. If you like getting greasy sh*t in your eyes, don't were any gogles when you're underneath, looking up.
  9. Remove the safetywire from the rear-most bolt of the shifter coupling and back the bold out until you can work the coupler free from the shifter-shaft.
  10. Loosen all the lugs on both rear wheels.

Time to jack up the bus:

  1. Jack the back of the bus up and put it on jack stands or whatever you like to use, but make it SAFE because you're gonna be underneath it banging around on things.
  2. Remove the rear wheels.
  3. Remove the hub nuts (that you already loosened, right?) and hubs - you may need to back off the brake adjusting stars to get the hubs off - depends on how diligent you've been in keeping your rear brakes adjusted.
  4. Remove the parking brake cables. I removed the adjusting nuts (2 10mm on each) up at the front under the handbrake lever so I could just pull the cables through to the back of the bus. That's how Muir says to do it.
  5. Take off the brake fluid reservoir cap and put a plastic baggy on the opening then put the cap back on tight. This will form a suction and not allow all your brake fluid to run out when you open the lines.
  6. Remove the metal brake line where it goes into the brake backing plate (11mm open-end wrench). Be sure and have your brake fluid bucket ready to catch whatever drips out. If you did the previous step, there won't be more than an ounce or so.
  7. Remove the "U" clip that holds the brake line to the axle tube (and pry the brake line out of the bracket if you need to). Some WD-40 always makes these things easier.
  8. Remove the lower shock absorber mounting nut (17mm?) and drive the bolt out so the shock is hanging there from the upper mount only (use lots-o WD-40 here)
  9. Remove the bolts (4 per side) that hold the redux boxes to the spring plate. Look at the spring plates from the engine compartment and you'll see them, 3 in a vertical row towards the rear and 1 off by itself about 2 inches to the front of the others. These should be 19mm, but I had a few odd sizes on mine. A few of these were pretty tight!

OK, ready to pull the whole thing out?

Make sure there's nothing attached anywhere on the tranny, axle tubes, brake plates (except for the e-brake cables which are already pulled out of their tubes), and redux boxes.

  1. If you've got any friends left, now would be a great time to have a few around to help balance this thing as it comes out. Those redux boxes are pretty heavy and the whole assembly is gonna look kind of like a Klingon Bird-of-Prey from Star Trek. Not to mention the fact that its 18 inches up in the air.
  2. Put your floor jack underneath the tranny (with a block of wood between the jack and the tranny) and jack it up just a tiny, tiny bit to relieve the pressure on it. You'll want it to be underneath the rear-most drain plug, to the rear of the frame. If you put it in front (front is front) of the frame, you won't be able to roll the thing out. Besides, it balances pretty damn well with it right under the rear-most drain plug.
  3. Remove the two 27mm bots that hold the carrier to the frame.
  4. Carefully pull the whole thing clear of the bus. I slid a cinder block (about 6" high) under the front (front is front!) of the tranny so when I lowered my floor jack, the redux/brake ends rested on the ground and the tranny remained fairly level resting on the block in the front and the jack in the rear.
  5. Remove the brake backing plates. You don't have to remove the brake shoes - you can take the whole thing off as an assembly. First remove the 4 bolts that hold the stub axle bearing housing in place (14mm?) and pull it off. Then remove the 1 bolt that holds the wheel cylinder on (bottom center - 13mm). Then remove the 2 nuts (or bolts) that hold the adjusting mechanism on (15mm?). Now you can pull the entire backing plate assembly (complete with shoes, cylinder, cable, etc.) free from the redux box. It may be possible to do this step with the tranny assembly still in the bus, I don't know, I didn't try.

Now for the good stuff

This ONLY applies if you are not planning on taking the entire assemble whole to a local shop to be serviced. I'm shipping mine so will need to break it down a bit more.

  1. Remove the seven 13mm bolts that hold the redux box halves together and GENTLY beat on the boxes (there are 2 places to do this - one in each direction) until they separate. Don't worry, none of the guts will come spilling out. Except for maybe a bit of tranny fluid - have some rags ready.
  2. Remove the six 13mm nuts that hold the axle tube retaining ring (looks like a big ashtray as one listee put it) from the transmission. Again, be ready to catch a little extra tranny fluid here.
  3. Loosen the axle boot clamps and slide the boot clear of the axle tube retaining ring. Be ready for a little tranny fluid here too.
  4. Remove the circlip on the redux box end of the drive axle.
  5. Remove the bearing from the redux box end of the drive axle. I had to put a screwdriver between the gear and the inner housing and smack the end of the axle a few times with a 5lb sledge hammer before I could get enough clearance to get my gear puller on the bearing. I don't condone this action!! There is probably some special tool for this, but I didn't have one, it was late, and I was running out of curses to lay on my bus.
  6. Once the bearing is off, you can just slip that big gear right off. Put all the guts (circlips, bearings, etc. in a baggy - you're gonna need to clean everything up real good when you reassemble it all).
  7. Now pull the axle tube free of the tranny - it should slip right off and pull it all the way off the drive axle which will still be attached to the tranny
  8. Pull out the big white plastic dome thingy from the exposed side of the tranny.
  9. Using a STURDY pair of circlip pliers (the cheapy ones I had from AutoZone kept twisting and wouldn't work) remove the BIG circlip that goes on the transmission end of the drive axle. This thing is about 3" diameter.
  10. After removing it, you can pull the drive axle free from the tranny. When you do, there'll be a big thrust washer that will come out on the axle.
  11. Remove the 2 metal plates that the axle was sandwiched between (otherwise they'll fall out when you move your tranny - ask me how I know). Stick them, the big circlip, and the thrust washer in a baggy to be cleaned up later.
  12. The gears that drive the axles will pull right out too. I don't know if you're supposed to remove them, but I did because one fell out when I tipped the tranny on its side. Just warning you...

Well, that's about all I know about it (for now anyways). I'll be sending my tranny to the shop to be rebuilt and I think I'll send my redux box/axle tubes along as well to have the bearings inspected/replaced as needed. When I get everything back and do the reassembly, I'll write it up too.

Of course, when I put all this back together I'll need some new gaskets and oil seals for the redux boxes - the shop can't put them on because unless you're going to get your tranny back with the tubes and boxes already attached you'll have to do it yourself.

Disclaimer: This writeup was done the same night I finished removing mine so everything should be pretty correct. But bear in mind that I had no manual and no prior knowledge/experience with this so there may be some steps that could have been done easier or better. Safety THE most important thing to consider when working under any vehicle - especially one as top-heavy as a bus. If you don't have a safe, level place to do this stuff, take it to a shop and pay the extra couple hundred bucks and have it done for you.

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