Lining up chummy engine with its gearbox!

[dockerpt]

Good day

I removed my wife’s chummy engine 
so I could swap out the ring gear.

All done....trying to offer engine back up to 
gear box.... 

Someone help with tips and magic!!!

Any advise gratefully recieved!!!

Best

Pete

[Nigel was in Brittany]

Don't forget there is a blind spline on the clutch center plate, its much easier with the gearbox removed and assembled to one unit on the bench (floor )

["Slack Alice" Simon]

I have just done this.   Was not looking forward to it.

Before anything else, the clutch plate has to be centred.   I have a very crude piece of thin ally with a hole chiselled out of it, but it does the job.   Almost impossible if not centred.

Front of car up on axle stands as high as they will go, and one rear wheel off the ground.

Engine in, not bolted down, as far forward as it will go.
Blind spline at top dead centre.

Gearbox in top, with blind spline at tdc also, as best you can judge.

From underneath, lift gearbox and offer up to engine.   You can tell by the relationship of gearbox flange to the stud ends as to whether it is tilted or more or less evenly spaced all round.

Jiggle the box and push towards engine.  If it doesn't mate, keep contact with the engine and rotate the gearbox output shaft one spline clockwise, using the propshaft flange.   Usually you can feel the next spline position, though it isn't easy whilst holding the box.

Balancing the box on a jack helps, but I didn't need it this time.

No joy? try another clockwise spline, then one or two anticlockwise.

Still no good?   Check alignment - is everything squarish on?   Did you REALLY centre the plate?

I was lucky - it went in second go.

If it had taken more than half an hour, which it can if it is being unkind, then I would have taken the weight of the box on a jack, and maybe replacing two studs with longer ones to help guide and take the weight a little, also.

Or put engine and box in in one go.   Which I didn't want to do, and luckily, didn't have to.

Cheers

Simon

[Rick F]

My 1929 Chummy engine/gearbox combination does not have a blind spine.

The hardest job on engaging gearbox is getting the floppy levers to fit into the slots on the release bearing. I usually tie them together with a bit of string and cut it off after mating.

[Viteran]

Does anyone know the logic behind the blind spline, ? it seems unnecessary. I first came across it when I was about 16, but 50 years later I know a lot more magic words to help
Ian

[John Mason]

The subject of the blind spline was chewed over at some length on the old forum without any real result. I myself think it was for quickness in assembly at Longbridge when on the production line.

John Mason

[dockerpt]

Best Got the engine and box to mate still not right even less travel
 on clutch peddle bugger....  not enough travel in peddle and slight
 drag when you rock the car with clutch pedal pushed....

The little arms aren’t quite all the way in their slots?
Have I screwed up the clutch assembly when
I swapped the ring gear?

[Robert Leigh]

Best Got the engine and box to mate still not right even less travel
 on clutch peddle bugger....  not enough travel in peddle and slight
 drag when you rock the car with clutch pedal pushed....

The little arms aren’t quite all the way in their slots?
Have I screwed up the clutch assembly when
I swapped the ring gear?

It sounds strange that any Chummy would have a master spline. Unless someone has changed things all A7s with three speed boxes did not have a master spline at manufacture.

[Ruairidh Dunford]

I have several three speed boxes with Master Splines Robert - they are a total pain!

[Mike Costigan]

Indeed; every three speed car I've owned has had a master spline.