Fitting an 1100 gearbox. How difficult?

[alibee]

As above, it's becoming clear that my gearbox will probably need swapping out for an M97 at some point, how difficult is it and what specialist skills/tools are needed?

I have a garage with nice fat beams to suspend the bike off, a decent set of standard tools but no specialist BMW kit, no presses, lathes, etc..... I'm happy doing basic servicing on most bikes (clutch plates, fluids, ducati timing belts, etc) but not super-fiddly bits like desmo shims or anything where the use of a hammer may result in a sub-optimal result....

Give it a go or let someone with some serious beemer history have a crack at it?

Any advice warmly welcomed!

Ali

 

[dazco]

HIya Alibee, i had to do this a couple of years ago on my 1100 .
It was harder reading about it in the clymer manual than actualy doing the job itself.
Its just a bit time consuming disconnecting all the other bits and pieces so that you can lift the rear subframe.
You will need to make some studs to replace the two lower mounting bolts these were just longer M8 (I think) capheads with the heads sawn off.
They replace the two bottom mounting bolts and act as a guide for the gearbox to be pulled back without it dropping.
Youll also need to use a trolley jack under the gearbox so the whole lot can be rolled away from the engine.
Splitting the box from the engine may take some time, mine was "stuck" to the engine and gentle tapping all around the join with a soft faced hammer eventually freed it.
The only special tool you may need is a Clutch alignment tool, but these are cheap from most of the usual supliers , however i made one for nowt and has worked fine .
Just take your time and it should be ok.
Have fun

 

[D6]

take the clutch pushrod out through the rear , easier to withdraw the gearbox then , rest is piece o p*ss

 

[Dragon Master]

Hi Alibee,

I'm just on with this now on mine. As Dazco says, most of the work is taking the other stuff off. Not sure what he means about making the new studs, I don't have anything like that on mine. There are six bolts fastening the box to the engine (three each side), and a couple of dowels to guide it off/on, but they stayed firmly in the engine on mine. Just make sure you don't lose them if they do come out. In fact if I remember right from about seven hours ago, the top left mounting bolt (looking from the rear) actually goes through a dowel.

No special tools required. The first time I did this I used a jack to keep the box level as I withdrew it, but if you take the clutch pushrod out first, there's no real need for that; I've taken mine off and put it back on today on my own, by hand.

Soft faced mallet is useful, as Dazco says, you might need to do a bit of tapping around the joint with the engine to loosen it, I did the first time. Also useful for persuading the through-bolt at the forward mounting for the sub-frame to come out; spin the nut till it's flush with the end of the thread, then tap it. Once it's in the hole, if it's still tight, a bit of brass bar slightly smaller diameter can be used as a drift if needed.

It's a bit time consuming, but it really is harder reading about it. Just make sure you remember/make notes of how everything fits, for when you put it back together. I'm just off out to remove the sub-frame again, because I forgot to make sure the brake pipes for the rear brake are routed behind it...

Dave.

 

[Paul G (BHT)]

Ali,

All you need is a couple of wigs some womens clothes + a fine bottle of scotch and the job's easy.... see here

 

[Colban]

Ali,

All you need is a couple of wigs some womens clothes + a fine bottle of scotch and the job's easy.... see here

Now thats just scarey.Accurate;but scarey.
To stop you dropping the gearbox onto your fingers as you batter,sorry,persuade it gently with a rubber mallet off the back of the motor,replace the top two mounting bolts with 8mm x 100mm long studding to act as supports.
If you can work on a Ducati,you can work on one of these old tanks.