Hi-speed ring & pinion vs overdrive

MikeK said:
Exactly my point. It DOES NOT look stock, as you originally stated. I've seen lots of them. Its the first thing I notice when I look at the interior of A's at events. Maybe I'm too picky. I'd like to see an install of a synchro O.D. trans without anything visible in the cabin.
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there will never be anything like that available. The stock transmition case is to small to fit another gear in it, and all electronic O.D. have some kind of a switch, and lever usually mounted on the steering column or sticking out of the floor board. And of course theres the mitchell that performs the best but is the most obvious. the 4 speed is the most stock appearing one on the market as of right now. For me, i dont really care if my car looks stock or not. I like being able to run 65-70 mph down the highway so that i dont get run over. I would rather have my car look modified than have a bent frame and an un-repairable body.
 
Logan said:
there will never be anything like that available. . .
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What makes you think so? A re-designed top cover could be made for either the F-100 4 speed or a T-5. A 4x4 T-5 could also be adapted to a torque tube and fitted with a remote shift mounted on the top cover in the correct stock location. Properly done, you would have no visible mods in the cabin.
RemoteShifterForModelA.jpg

An alternative is to directly access the shift rail, I have CAD drawings for that.
 
I have the 3.54 in my '31 Tudor with 19" wheels and it works great. In the "28/29's with 21" wheels, it robs a little power when climbing hills. The taller wheel changes the ratio. On flat ground it is great.
 
In "Those Unauthorized Accessories" there is an overdrive that fits inside the rearend, so the car looks completely stock but has overdrive. I wish I could find one of those units.
 
Tom Wesenberg said:
In "Those Unauthorized Accessories" there is an overdrive that fits inside the rearend, so the car looks completely stock but has overdrive. I wish I could find one of those units.
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I'm guessing you are talking about a Twin-X. They have a special housing on one side. A buddy of mine has a perfect one and has been offered nearly 5k for it. I'd like to have it but not that much!
 
I've never seen one, but for sure that's also out of my price range.

BTW, with the overdrive in the rear how is the speedometer error corrected?
 
Hello: I had the 3.54 installed last month..took out 3.78 ..u lose upfront take off but once u get going its great. Quiets engine down somewhat so you can enjoy ride better. This I did because of cost of overdrive out of reach. good luck josh1331.
 
Here's my HOMEMADE overdrive. I used a '53 Borg Warner unit and have all the advantages, ie free wheeling, electric shift, kick down etc.
Total cost -$100.
Disadvantage-- you have to pull the "lock-out" cable to back up. I usually just leave it locked out unless on the highway anyway.
 

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tubadon40 said:
Here's my HOMEMADE overdrive. I used a '53 Borg Warner unit and have all the advantages, ie free wheeling, electric shift, kick down etc.
Total cost -$100.
Disadvantage-- you have to pull the "lock-out" cable to back up. I usually just leave it locked out unless on the highway anyway.
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:rolleyes: One thing I am curious about is what the advantage is with 'free-wheeling'. I have always thought of them as dangerous and a nuisance. What am I missing?:o

.
 
2manycars said:
I have 3.54:1 in two of my cars. It's a small difference, but noticable and nice. I put a mitchell in Barry's coupe and liked that, and found that except for steep hills, I could just leave it in overdrive. If I could do that with a 26% gear up, then I would think a 13.5% gear up would be fine in this area. In the rocky mountians, not so much. I have a 3.27:1 gear set that I plan to use in my speedster.
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As Bill says the coupe is great with the 3.78 rear and the Mitchell O.D. He also added a Snyder 5.5 head and I find the combination to be ideal :). On my 30 roadster I have a 3.54 rear and stock head and I don't see much difference from a stock Model A. Perhaps the better combination for this car would be a Snyder(or Brumfield) 6.0 head and a 3.27 rear.
 
I like the elimination of engine vibration on deceleration. Not a lot of advantage I guess beside novelty, maybe a litte milage increase because the engine isn't reving on long downhills.
Dangerous--- Maybe if you had no brakes. I know you can coast 70 downhill in the Rocky Mts. just like kicking her out of gear. You have to disable the governor to do it or you'll just upshift to OD.
 
Geo. H said:
I don't suppose this will help, but I put 3.54 gears in my roadster, and then installed a Volvo overdrive and a 39 trans. Sure is sweet to drive. I think if I had it to do over again, I'd stay with 3.78 gears, but I'd stay with the OD and 39 trans.
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Geo,

I am curious about your 39 ****** setup. I am working on a V8 ****** with a '46 gearset for the coupe.

1. Which gearset did you use, 16/28 or 15/29 or one of the Zephyrs? (personally I think the Z's are too high in 1st and 2nd for an Model A or B engine, at at least when looking at it on paper).

2. Also do you have reground cam or stock or Stipe IB330?

3. What altitude do you run at?

4. What is the Volvo OD ratio?

I have 3.54's with a B engine, 7.0 Lion head (the Lion head is a recent addition ... "large B head" had similar loss of lowend torque), regrind "B" cam and Zenith B in the coupe now.

There is a notciable loss of low end torque when I compare the B engine to a tired old stock A engine with "large B" head, stock (unreground) A cam and B Zenith I have.

The difference is like night and day, the stock A cam just out shines the reground B cam at low RPM, like right after I shift from 2nd to 3rd and up until 50 or 55. These tests were done 6,000 feet up to about 9500.

Like Marco said the cam makes all the difference in pulling tall gears as far as I can see! At least from what I noticed when comparing my two engines.
 
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MikeK said:
Exactly my point. It DOES NOT look stock, as you originally stated. I've seen lots of them. Its the first thing I notice when I look at the interior of A's at events. Maybe I'm too picky. I'd like to see an install of a synchro O.D. trans without anything visible in the cabin.
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That's also what I'd like to see, a good overdrive ****** with no mods to the frame or crossmember. Now, who can squeeze a fourth gear into a Model A ****** case????
 
I put a T-5 and Hi gears in my 29 with 16 wires behind a warmed up B, she, many times wound the speedo as far as it would go, and the engine was just breezing along. That was in Florida, it was a bummer in St.Thomas on the mountain roads. LOL Iceman
 
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