I have interest in buying a relatively rare ring and pinion gear for my Formula F car. The seller says it needs to be resurfaced. I have not heard of this being done to a ring and pinion gear....anybody able to illuminate the process for me please?

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Would that be akin to grinding a cam? A pattern is needed for that. Maybe just micropolishing like a crankshaft? But a crank has flat surfaces the polishing tape can reach. I guess some online research is in order.

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Tony H
W111 280SE 3.5 Coupe
Manual transmission

Past cars:
Porsche 914 2.0
'64 Jaguar XKE Roadster
'57 Oval Window VW
'71 Toyota Hilux Pickup Truck-Dad bought new
'73 Toyota Celica GT

I’ve never heard of that, but if there is enough room in the adjustment process, it might be plausible. On a third member like a nine inch Ford, you have adjusters that could turn quite a distance. I suppose you can add enough shims to those that are shimmed, but it might result in a force being cantilevered beyond its area of strength.

I‘m not a machinist so it’s difficult for me to comprehend how you would go about the process. I would think that it should not involve very much removal of material if it’s going to be successful.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I talked to my favorite machinist, Homer. He says there could be just enough gear wear to require adjustment and re-lapping the faces so they mesh properly.

Also it could be rusty.

He is going to check with a local guy who used to do that and see if he still is.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Yeah, if you could get a uniform surface it would help you see the pattern while setting it up too.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I would have expected the pinion to be case hardened. But apparently, refinishing is a thing:

https://www.detroitspeed.com/gearfx-service-rem-deburr-and-micro-polish-ring-pinion-gear-070151

nonsense. just get a hunk of titanium and take your diamond file to it. easy peasy - better than new!!

Thanks! That looked like they might be suggesting the treatment on brand new parts.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Amazing & fascinating .

? What's the ring and pinion from originally ? .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

I'm not sure but may be a VW part.

The fellow offering a used part needing resurfacing discovered it is not the right gear ratio.....his is same as mine 3.1.

Drat!

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If it’s a VW product you would think it could be found assuming that the ratio you need was produced.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

Diameter of ring? 3.1 is an unusual ratio...have you counted the teeth, or the number of output rotations per turn of the pinion?

In every one I've ever seen the ratio is stamped on both the edge of the ring gear and the nose of the pinion gear .

It's been a long time since I fooled with VW transaxles but VW made a bewildering array of ratios over the years so I imagine once you're counted the teeth and done the math it should be possible to contact say Rancho Transmission (Riverside, Ca. I *think*) and ask them to sell you a gear set .

Having worked on many a noisy final drive over the decades I'd think any rust no matter how slight would mean scrap time .

VW do Mexico still makes plenty of parts for old VW's, maybe find a copy of 'Dune Buggies And Hot VWs' magazine, they used to have a page in the back that told you on which page what product could be found, there's always lots of vendors .

Maybe SCAT in ?Hawthorne? Ca. ? they're still in theVW parts biz and are near the mall .

Good luck hunting, keep us posted please .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Thanks very much! The vw angle may end up being a good path.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

How is that 3:1 accomplished? 60 to 20? 30 to ten? Other possibles but tiny (12:4, 15:5)