Crown Wheel Question

[Ian Williams]

Very interesting Matthew, I also own a Nippy, body #840, I would be keen to see more pictures of yours especially of features believed to be original.

[Chris KC]

Chris KC - I meant to ask you on the other thread, out of interest how did you come by it? 

Apologies, I didn't see your question until just now. I wish I could relate some kind of detective story but the truth is far more prosaic - I got lucky rummaging in the bottoms of cardboard boxes at autojumbles. I'd looked over the same stall at least 5 times already but went round the field one last time before heading home... It was caked in grease and dirt so I guess anyone who spotted it left it alone.

Just curious, what ratio CWP was in your Nippy axle when you acquired it?

My own experience of axle building is limited but I've done a few. You have to go through a lot of differentials before you find one with less than 4 thou run-out, and those I tried to correct by machining had only partial success. I've thought a few times about shimming them but...

As for the adjustment of crown wheel and pinion, it's tricky. The last new pair I did was very much a compromise between drive side and overrun - couldn't get both perfect. It's still running though...

[MatthewMyerscough]

Ian - my car is March 1936, you are welcome to see more pictures. I must admit I am still discovering things with it that may or may not be original. I took quite a few photos of my car when I dismantled it recently (to start the large mechanical part rebuilds like the axle). 

Chris - No need to apologise, I was just intrigued as to its history. What a find that was in an Autojumble, I wish I was that lucky. It makes me wonder what else is out there buried in boxes and hidden in garages/workshops.

As for the CWP - it is a sports ratio 8/45, when I first got the car I didn't know how much of it was original. One of the first things I identified was the 'S' stamp but I didn't know if the internals were correct until this rebuild. With regards the run-out I must have been lucky by the sound of it. I just cleaned and re-assembled the diff and it was certainly no more than 4 thou, I didn't have to make any specific adjustments.

I know what you about the adjustment, it is tricky. I spent many hours trying to perfect it. I focused on the drive side predominantly to get a mesh right, the over-run wasn't quite as good but I am happy with it on balance, accounting for 88 years of wear.

Thanks

Matthew

[dickie65]

Good work the later bluing pictures look a lot better.
Nice find of the correct axle ( S )
I have one hiding behind my lathe.
The Van Ratio is identical.
I am running brand new interals in a box saloon casing. ( I dont want to break the original axle )

[MatthewMyerscough]

Hi Dickie 

Thank you.

I was pleasantly surprised to find the 'S' stamp underneath all the rust. I know what you mean about not wanting to damage your original axle. I feel exactly the same with every original sports part on my car. 

I am keen to get the car as close to original as I possibly can.

Thanks

Matthew

[dickie65]

Hi Matthew.
You probably have not seen the way I drive.

https://youtu.be/alFAAk2Fv74?si=mIfdOK5rAFCxNueQ

[MatthewMyerscough]

Hi 

That looks like good fun, I wouldn't mind having a go at one of these events in my car when it is back on the road.

I would certainly swap out my Nippy engine first though   (just in case).

Matthew