Stub axle/swivel upright fit.

[ColinChandler]

Hello all,
I've read other threads about fitting Marina stub axles to Minor uprights but how easy is it to change one Minor stub axle for another?
I have a NOS Minor upright without a stub axle and plenty of worn ones which do. Cutting an old upright to get the stub axle out would be ok but how easy is fitting that stub axle into the new upright?
Previous threads suggest putting the pin in the freezer and the upright in the oven should be ok but is this sufficient to give me a sporting chance of getting them together?
Many thanks, Colin.

[philthehill]

Changing the stub axle is very easy so long as you have a hydraulic press. The last set of Minor stub axles I removed only required approx. 4 tons (or less) of pressure.
The thing to watch out for is the stub axle picking up when being pushed out of the swivel so make sure that there are no burrs on the stub axle.
I would recommend that the stub axle is pushed out from the wheel bearing side of the swivel as that allows the circlip which fits into the recess on the inner side of the swivel to be accessed though it is not imperative that the circlip is removed. Make sure that when pressing out the stub axle the hub nut is installed with its outer face at least level with the outer end of the stub axle.
The circlip does tend to rust away so you may have to change the circlip which is a reasonably easy job.
When fitting the stub axle make sure that the circlip is fully home at the bottom of the recess.

Below is a pair of Marina stub axles which are similar to the Minor stub axles except they are of a larger diameter and have a different arrangement for locking the hub nut.

Marina stub axle.JPG (1.05 MiB) Viewed 1030 times

The above Marina stub axles were removed by cutting and grinding away the stub axle boss and being very careful towards the final removal of metal.
I removed the stub axles that way as a previous Marina NOS swivel/stub axle picked up when being pressed out.

I would try pressing out the Minor stub axle first as the interference fit does not appear to be as tight as the Marina with its disc brakes and taper wheel bearings.

Good luck

Phil

[ColinChandler]

Thanks Phil,
I was hoping you'd be along with some wise words and wise pictures too. Much appreciated.
I think I'll have to take it to someone who has more oomph than I have then. The last thing I want is to get it stuck halfway.
Thanks for the guidance for which way to push it out and that's also a good point to leave the hub nut in place to protect the thread.
Thanks again for your help. Again, its much appreciated.
Best wishes, Colin.

[ColinChandler]

Hello all - An update.
Being a little concerned at pressing the old stub axle out and having it pick up, I decided I'd have a go at getting it out with a few judicious cuts with a slitting wheel in my grinder. After a few measurements to work out the wall thickness, I marked the depth on the slitting wheel and gently cut away. I did both sides and easily tapped the stub axle out. Unfortunately I didn't get it right as the slit up the stub axle on the left shows. That's totally scrap then. Moving onto attempt two on the right, I cut off the surplus material and along the lines of what Phil described, ground the boss away keeping a careful eye on what and where I was going. I was helped by the heat colouring of the material when it became thin. Again it was easy to tap the stub axle out but this time I hadn't gone through anywhere and the stub axle is reusable.
Hope this helps anyone considering the same. There's a limit perhaps to how many scrap uprights everyone has.
Cheers, Colin.

[ColinChandler]

Here's a further post on the continuing saga of pressing a stub axle into a NOS swivel upright. Its a case of "what could possibly go wrong?"
Armed with my swivel and stub axle, I set off to have them pressed together. Handing them to my press mate, he peered at them and said "there's going to be a big bang somewhere if I do this." Looking puzzled, out came the Vernier and he showed me. The stub axle is around the .982" mark which was what I'd read somewhere on here that it should be. Unfortunately the hole in the upright is .875" which is miles different. So, I'm not sure what year the upright is or even if its for a Minor but its certainly changed along the years. As shown in the comparison photo of the previous upright and the NOS one, there's not even scope in the casting to bore out the stub axle hole.
Onwards and upwards.
Best wishes, Colin.

[philthehill]

Colin
I have just measured the two Morris Minor spare stub axles I have on the shelf and they are.

1...…………..0.985"

2...…………..0.986"

The swivels and stub axles are the same as far as I know for the Minor 1000, the Wolseley 1500 and the Riley 1.5. The only difference is that the Wolseley and Riley have the steering arm in the upper boss of the swivel.

As regards boring out the stub axle hole to suit the stub axles you have - there is no problem in doing so providing you can get the swivel in a milling machine or lathe and the new stub axle hole is square to the swivel.

I had the two swivels on my Minor bored to accept Marina stub axles which are 1.061" in diameter.

My Ser 2 also had the swivels bored for Marina stub axles.

There are tables for the interference fit between two pieces. The table is expressed in interference relative to diameter.

I have the table somewhere but just at this moment cannot lay my hands on it.

There are various interference fit tables on the web.

Phil

[ColinChandler]

Thanks Phil,

You say what I've always thought, that the same upright is used across the board with just the steering arm in a different boss. I just didn't realise things had changed along the way.

I am a little concerned though that there will be enough material left in the casting to bore the stub axle hole to a larger size. Roughly measuring it, the wall thickness at the thinnest place is around .15" as it stands now. Its visibly much thinner than the beefed up casting which suits the .985" stub axle.

I wonder if its possible to find when the stub axle/casting size changed and then go looking for a worn upright from that era so I can take out that one's stub axle to use in my NOS upright.

Or maybe its one to put down to experience?

Thanks again, Colin.

[philthehill]

Colin
Looking at the photo of the two swivels there certainly is a difference in the amount of metal around the stub axle hole.

Looking at the MOSS Europe spares web site there does appear to be an early and late stub axle. Both NCA. Correspondingly there are early and late wheel bearings.

The differences between the items I am not aware of.

Phil

[ColinChandler]

Hello Phil and thanks for that.
Yes of course, the bearings will be different too. I'd not really thought that through. I think I'm going up a bit of a blind alley here as its all getting rather convoluted.
I'll just stick to the later model parts and keep everything simple and consistent.
Thanks again, Colin.

[RobThomas]

Series MM stubs are much smaller. Looks like the .875 is for one of those.