pinion opinion

[JonE]

Cleaning old spares to work out if of use or not. This is 8 teeth, thread raises to left so presumably LH thread, and the shiny bit is oddly 12 or 13 thou over 1" dia. 
22 1/4" long.
Could someone please identify?    

[Parazine]

1932 - 35/6, 8 x 42, 5.25:1. Is there a matching crown wheel? Sadly, if it's a singleton, it's not much practical use.

I'll probably get shot down in flames by people who regularly run mis-matched CWP, run together with carrot juice and cat food to polish them in......

[JonE]

thankyou. so presuming the extra 12 thou are meant to be just "1 inch"...
Yes, that was my thought too re. use - no - no crown wheels stored with - but at least I can catalogue it appropriately. (Of course it has no chips, like the perfect chocolate teapot).

[Chris KC]

From what I can see that looks in quite good nick and personally I wouldn't hesitate to use it if I had an equally sound but unmatched pinion. I might set it up and run it in carefully, but that's pretty much a given here. Of course it's very hard to tell the condition of a part from a photo...

[Bob Culver]

Mild rust pitting as distinct from extensive fatigue need not preclude use. My car stood unused and unmoved outside for several years and condensation pitted diff and gearbox gears but examined after 10,000 miles running semed not to have had dire effect and not notably  noisy. Many hours can be frittered searching for the optimum setting of used and more so of unmatched pairs. Removal of the short wear step at shft end simplifies. Judging by the way diffs are split and reassembled for axle replacement with different gaskets, exact meshing is not too critical. I am alwys intrigued by the number of reasonable stray pinions. Would expect the lesser wearing cws to survive.
Is your mike seriously wonky otr ha sit been built up to 13mm for some reason?

[Ian Williams]

I cant say why it is 12 thou oversize Jon, unless you have mistaken the measurement?? In good order I have successfully matted unmatched CWP in the past so I would say it is certainly worth keeping.

[Hedd_Jones]

Got loads of lonely crownwheels here...

[dickie65]

Any More O Pinions ???

I would not worry about using miss matched CWPs unless excess wear is present.
I still have a brand new Regent CWP for a Ruby axle and another matched Box Saloon CWP left over from my fathers buying in the 1970s.

[Duncan Grimmond]

Pinion opinion reminds me of "Moses supposes his toeses are roses..." a really sad git here, sorry!

[Bob Culver]

Hi Hedd

My father used to say he would rather see a nice cw in a china cabinet than some ornamental crockery. Perhaps you could get them bead blasted and lacquerd and sell as ornaments/conversation pieces.
If mixing, the same manufacturere would be an obvious start and nothing with an obvious worn indent area. Can spend a lot of time and with the 4: 42 ratio the teeth work in two sets which can further complicate "readings". A smooth feel of the rotated pinion can confirm a reasonable apiring.
As with so many other parts it is very annoying to find seemingly good parts ruined by rust, even jf orphan pinions.