Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Centa spline failure

Sorry to be a bit late with this.

Dan, my support bearing does not contact the crankshaft at all so no worries there.

Crush washer? These are for setting up such things as pre load on taper roller bearings in mass assembly applications - I can see no use for one here.

The Centa set up does not have any axial loading at all.

Any spline drive which will not transmit the load without the retaining nut being tight will fail - no ifs or buts.

Roll smith - There is little point in assembling something with worn splines and I doubt if loctite will withstand the forces we are dealing with here, but it would be good to hear from someone with experience of this.

On the bright side, my machine did several hundred miles making the rumbling noise with no apparent damage to the crankshaft.

I will soon have some gauges ready for people to use to check their crankshaft splines for wear.

My repair solution which seems, so far, to be successful can be seen here in the image gallery. http://www.bleazey.co.uk/M3W.html#Image I will have some of these repair inserts ready soon.

Phil

Phil, what's the purpose of boring out the splined hub? Are you going to insert a new spline?

Maybe I'm not seeing the whole picture, so to speak.

Hello Dan,
You are, indeed not seeing the whole picture!
Click this and all will become clear, you will see the new spline, the old coupling bored out and the new splined hub being inserted.

http://www.bleazey.co.uk/M3W.html#Image

Yes, I went to you website, but all I see on the splined hub is that it's inserted half way into the housing and there's no spline on the coupling.





So is the spline on the other end and you have the hub in backwards?

Yes indeed this is the splined hub viewed from the rear. The end which goes in to the engine first is not splined. When it is pushed right in you can not tell the difference from the original - it is identical but better material and the splines are fitted on both major and minor diameters as well as the flanks.

Ah yes, then the rotor gets bolted onto the hub and goes onto the crankshaft at the same time as the Centa housing being installed...

I had S&S and Harley on my mind. They have a sleeve that is a spacer and also has the crankcase seal wear points. The seal now rides on the new hub instead of the sleeve, gotcha.

So the Centa takes a special rotor?

Thanks for taking the time to explain, greatly appreciated.

Have a great evening.

Any time, good night.

Hi Phil,
If my present Centa unit bites the dust, I will definity be a customer.

As an aside, do you have the equipment in your shop to do all this machining? Reason I ask is that I am a volunteer mechanic working on old aircraft and we machine a lot of our own parts and it takes a good deal of time and patience. We keep two WW2 bombers flying and the biggest issue is that the original systems were not designed to last this long.

Best,
Roland

I do all the prototyping and then get a more up to date machine shop to make the parts for other people's use. Yes, like lifeboats, bombers had a short life expectancy - sad really.