Remove the unit in sections - Overdrive, transfer + Hi-Lo unit together, then main box. This way you don't need a hoist (I'm 132 lbs and I could do it) and it makes lining up the pilot shaft a lot easier on reassembly.
Special tools- 19/32 socket, open end and box end wrenches, the heaviest duty set of snap ring pliers you can buy (for the snap ring on the output shaft in the transfer, and a torch - propane is OK - to heat the main box casing to remove the reverse idler shaft if necessary and to warm the transfer to remove the bearing races. The first race (I've forgotten if it's front or back) in the transfer that you have to remove is difficult to get out. I heated the box and tapped it out on an angle with an old screwdriver from the inside.
I think you are in England so parts should be cheap, but when replacing the mainshaft rear bearing get a double sealed unit from a transmission shop, use some good gasket sealer around the outside, and the oil won't leak from the main box to the transfer again.
The plain circlip on the front of the mainshaft is tricky, but be patient, use 2 or 3 screwdrivers to bend it out, and you'll get it. Don't reuse it.
If the rear bearing race for the layshaft does not cooperate and there is no hole behind it, drill a new hole to allow you to drift the race out. Be sure the hole is in the gasket area. If not, the oil will leak right out. You'll understand better when you look at the area.
While you've got it out, drill and tap the top cover of the main, transfer, and overdrive, install small hose nipples, and plumb some heat and oil resistant tubing up to the firewall. This will reduce the pressure and leaks as the box heats up and the amount of oil on you rear window.
Assemble the hi-lo unit to the transfer BEFORE bolting the transfer to the main box.
When replacing the pilot bushing, first try hooking the head of a nail under the front of the bushing in the flywheel, clamping vice grip pliers on the nail, then levering against the vice grips with the screwdriver. If this gets you nowhere put a grinding bit on your electric twist drill and grindout one side of the inside of the bushing. Don't go too far. When you're almost through tap it on an angle to try to turn it with a drift or chisel (careful of the flywheel). It should be loose enough at this point to pry/pull out. Soak the new bushing in ATF overnight before installing.
Output shaft bearing adjustment - the manual says to wrap a cord arount the output shaft and pull with a scale, and using a feeler gauge between the casing and speedo housing. Bull$3!+ on that! With bearings well oiled bolt the speedo housing down with one of the .010 shims removed (you'll find 3 sizes of shims in there - .015, .010, and .005. You shouldn't have to buy any). Continue to rotate the shaft while tightening. If the shaft grabs before you finish tightening the bolts STOP. Unbolt the speedo housing, add an .005 shim (or remove the .010 and add an .015) and try again. If the shaft does not grab continue removing .005 at a time (mix and match shims to do so) until it grabs and STOP. Undo everything, add .005 and replace the speedo housing for good (don't forget the speedo drive thing that goes inside - it's like a doughnut with diagonal threads on the outside. Yes, it does have a name but I don't recall what it is. Make sure it's the right way around). I tried the rope around the shaft trick with the fish scale on my first rebuild (done 3 now) and found the value is either too low or it is too high (grabs).
The jumping out of gear problem could be weak or stuck detent springs or it could be that the engagement teeth on the affected gears are worn.
As for gears, if they look a little worn, replace 'em. Bearings, replace 'em.
Sorry this stuff is not in order.
From what you wrote I don't think you'll have any problem. It's not brain surgery, believe me. I think you'll find it very satisfying.
Once you get it back together it may be noisier than before, but only for a couple of hundred miles or so once the gear teeth mate up.
If you run into any snags feel free to write me or the net.
Good Luck!
Bill Maloney maloney@wings.attmail.com
1. Remove front seats, drive shafts, clutch op mech -- esp the jolly trans brake assy! etc.
2. Unbolt tranny from rear of engine.
3. Take a sheet of *heavy* plywood and cut it to fit snugly between the gearbox crossmember and that immediately under the back of the engine -- ideally will be a tight drive fit. Support the center of this sheet with a suitable stand. The wood sheet should be absolutely flush with the tops of the 2 crossmembers. Doesn't have to be terribly wide -- about a foot across or so.
4. Unbolt yr gearbox at the two mountings at the back, remove 'em and lower gently down -- use a good bottle\trolley jack to raise the back of the gearbox. Back of the engine (flywheel case) will rest on the front crossmember and the gearbox will lie on your sheet of wood.
5. DRAIN THE OIL out of the tranny!
6. Carefully work the tranny off the back of the engine. You'll reach a point where the tranny pops off and can now be carefully slid to the rear. The wood sheet acts like a tray by preventing it from dropping down at the front. To remove completely, push the tranny slowly backwards -- the point will come when the rear end starts to pitch down past the gearbox crossmember. Once its touching the ground at the back, hop round, get underneath and a bit of pulling and wiggling will have it out and on the ground. (I'm assuming the Landie is standing on its wheels.)
To merely replace a clutchplate -- moving the tranny back on yr wooden tray about 8-12" will do.
7. Reinstallation. Get underneath and lift the bellhousing up until its resting on the gearbox x-member. Gently lift the back of the gearbox up whilst pushing. With luck, the bellhousing will easily start to glide forwards over the wooden sheet. A minute later and the tranny will be up nuzzling close to the back of the engine. Wiggle a bit to line up with the engine and voila! -- engine and tranny married up. Spin on the bellhousing nuts and bolts. Raise the back of the gearbox -- bottle jack -- insert and bolt down the gearbox mountings. Knock out the piece of plywood (stash for some other time!). Refit all the ancilleries. Done.
Doing a gearbox-out job this way is a pretty easy one-man venture: an extra pair of hands is a delightful luxury it available tho!! -- basically having a piece of gearbox support between the 2 x- members makes all the difference.
Good luck! Keith Coman
* Dept of Management, Rhodes University, Grahamstown, South Africa *
and another tip on removal. . .
I have always used an engine hoist to remove my transmissions, but my friend uses a musch simpler set up. He uses a piece of steel pipe resting on the inside gutters over the doors. The seem strong enough to support the transmission. He uses a come-along to lift the transmission using this steel pipe, and he has a wheel for sliding it left and right. He runs a one man shop and this is the only way he says he can do transmission jobs alone. He can move the transmission back and forth as well when he wants to do a clutch job. Dave VE4PN