Assembly of engine and gearbox into frame

RUSHTON · Post by **RUSHTON** » Wed Jan 19, 2011 5:49 pm

I am restoring Matchless 1944 G3L #70275.
I will shortly be coming to the point of refitting the engine and gearbox back into the frame. Since it was removed in 1989, I have forgotten the sequence and am puzzled by the number of spacers I have.
Can anybody help? I live near Exeter, Devon

itma · Post by **itma** » Wed Jan 19, 2011 8:33 pm

Ok
assuming it is all as standard with the correct spacers and not cut off bits of water pipe......

at the front between crankcase bottom and frame lug one spacer each side.

front engine plate has four, all same, two each side.

one, the largest, between engine plates.
your footrests should fit inside the frame tubes so no spacers there.

on gearbox top mount bolt, between plate and adjuster,

a small tube about 1 1/2 inch on centre case stud between rear chaincase and engine plate; the other one same size fits between cases; you may not have that it could be a nut and washer or he very late large nut.

what spacer goes where is easily determined by the size of the hole in it.

re the chaincase spacers, oiltightness of the case depends on the correct fit of these, they are not exact specific sizes it will be worth you while to read my missive on the subject.

I think thats all, good luck

RUSHTON · Post by **RUSHTON** » Thu Jan 20, 2011 9:33 am

Thanks for that - I rather thought they would be obvious. If I get stuck - i'll be back! R

RUSHTON · Post by **RUSHTON** » Mon Jan 24, 2011 12:06 pm

As the gearbox and engine are apart - would it be best to fit the gearbox to the engine and brackets, then into the frame. Reading the manual it recommends separating the front and rear frames for removal, whereas I have already assembled the frame and rear wheel. I feel that the weight would make it difficult for me to manage. I have mounted the frame on a moveable workbench to facillitate working at a sensible level.

chasdev · Post by **chasdev** » Mon Jan 24, 2011 2:58 pm

I've been wondering how the engine/trans combo's were installed at the factory as well, engine first then trans, or both bolted into the brackets and then the frame?

Don Madden · Post by **Don Madden** » Mon Jan 24, 2011 6:15 pm

Somewhere I have a picture of the assembly line early post-WWII. I shows a fellow that looks as old as I, (well past retirement age), lifting the complete engine & gearbox with plates by himself into a rigid frame rolling chassis. And that's an iron engine, too, much more than I can handle. Cheers, Don.

SPRIDDLER · Post by **SPRIDDLER** » Mon Jan 24, 2011 8:45 pm

Ah, Don, but it's essential to wear the white collar and tie with black waistcoat and a fag butt between yer lips.

(Relax Don. A fag o'er 'ere is a cigarette)

Blimey, you have to be so careful wi' these forriners.

itma · Post by **itma** » Mon Jan 24, 2011 9:10 pm

While at the factory the engine /gearbox was shoveled in as a lump this is not really practical at home on an old well worn machine.
I suggest you get the engine in place with the bottom front stud holding it all; then assemble backwards; you need to remember the dynamo strap swivel pin underneath as well as all the other dynamo holding bits; the bottom rear crankcase engine plate bolt has a thin head and goes in from the magdrive side; when the engine plates are in place push the footrest bar through as a help, if you leave all the nuts loose, you can then get the gearbox in from the offside.
I find it easier to leave the timing case off till the dynamo is in as fitting the mag platform can be tricky but then I always leave the head off as well.

the dynamo goes in easier from the T/S as well, you dont have to remove the band.
Mostly I always fit the engine less head and timing cover.

It is easier to fit the oil pipes then as well; be very careful not to cross thread this type that go straight into the case, if they don't go all the way home by hand, stop.

Do not do anything up tight until all bolts + studs are in place
last stud to go in is the one at the bottom of the saddle down tube, this always needs to be levered into place.
One thing I find invaluable is some steel rods of various sizes 1/4- 5/16- 3/3 ground to a long taper, these can be used to draw the lot together to align it all, saves bashing the studs through and ruining the threads.

last to go in then is footrests and the centre spacer.
Then all you have to worry about is the chain-case.

That's how I do it. Don't think I missed anything.
Of course if Miss January was in the workshop I wouldn't give a toss about some old motorbike.................

chasdev · Post by **chasdev** » Mon Jan 24, 2011 9:52 pm

Same procedure for twins? (engines, not females)..

hawkes · Post by **hawkes** » Tue Jan 25, 2011 8:37 am

A friend of mine recommends lying the frame on a mattress and then fitting the engine ? Not sure if lugging the mattress down the stairs and then returning it to the bedroom before the wife gets home would be more labour intensive ?