Cost Estimate to make more hi-speed rear axle gears for '30s Hudsons and Terraplanes

Jon B

Geoff and Ivan -- in mid 1938 they changed to eight 7/16" bolts.  Otherwise, the 1934 to 1938 gears were identical to the later ring and pinion (crownwheel and pinion!) gearsets?

Ivan, it sounds like you're looking into that possibility (of simply drilling some ring gears for 6 and some for 8, holes).  If these gears ('34 to '38 and '39 to '47) are otherwise identical, and you can drill them for 6 or 8 holes, I would think that you'd open up your market to a lot more Hudsons.  With each additional gearset, the price comes down, thus theoretically raising the demand even further.  Of course, from 1940 on up, Hudson offered overdrive, making the highway ratio gearsets less necessary.

Are you putting an ad in the WTN?  There are still a goodly number of Hudsonites not yet online!

terraplane8

Jon,

Can you tell me, what effect is there on acceleration and hill climbing with the 3.5 versus 4.1 ratio in your Terraplane? Mine seems pretty smooth at 60 with the 4.1 so I assume one could cruise pretty easily at 65-70 with the 3.5 with power in hand for hills is that right?

Jon B

My guess is that acceleration and hillclimbing would be adversely affected but I'm not enough of an engineer to say by what degree.  Perhaps someone with one of the 3.5's (which Pat had reproduced) in his car, could speak up.

ivanz62

I cannot claim to be an expert in which rear ends the gears fit.  They are the 6 bolt ring gears and I know they stopped being used somewhere around 1938.  I did buy an 8 bolt differential to see if gears could be made with both 6 and 8 bolt patterns.  Unfortunately, the ring gear is a totally different animal.  I bought a 6 bolt differential from Gus Souza some years ago to fix the broken rear end in my 1935 Railton.  He told me that one could replace the entire  differential and gears in a early car with an 8 bolt unit complete and thought making any gears for the 6 bolt diff a mistake.  Just change to the later style parts as he had been doing since the fifties.

Geoff Clarke's opinion sounds correct to me, but I have never seen the inside of a 33 rear end.  I know the 33 T-8s had different axle shaft from the T-6s.  So we are looking for interested buyers with 34 to 38 Hudsons and Terraplanes.  Maybe Hudson 112s?

As far as the questions about drivability, Richard Esparza's experience is a good test.  The ability to cruise at modern highway speeds without revving the motor too much is the big gain. Jon B is correct that acceleration and hill climbing would be somewhat affected, but being able to drive on the flat level roads which is what is being done most of the time would be safer because one would not be the object of continual assault from the rear.  And safer for the engine because of lower RPMs on the highway staying in the design range of the splasher engines.

[Deleted User]

I'm interested!

ArkieJazz

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