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Originally Posted by Anthony
Ed, a lot of good info !!
Yes, I know racers would take stock gears, and grind off every other synchro tooth, to enhance power shifting, strictly a racing modification, not for street, as the picture of your liberty gear showed.
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Spot on Anthony. The Pro Shifted and any of the Pro Shifted variations are race only mods. They make for a very unpleasant street experience.
Quote:
Originally Posted by Anthony
GM modified the M21 close ratio gears, decreasing the tooth angle, which strengthened the teeth, I guess mainly for drag racing, and named the tranny M22, still using the same ratio's as M21.
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Correct again. I can't recall anymore but I believe they might have used a better steel for the gears also, perhaps a higher nickel and/or molybdenum content.
Quote:
Originally Posted by Anthony
Also, the higher the gear multiplication, the less torque the tranny can handle, so keeping all other things equal, a M21 (2.2:1) should be stronger than a M20 (2.56:1)
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Correct again! When you put the mechanical advantage in the transmission through the use of lower gear ratios the strain is transmitted through the mainshaft and countershaft to the actual transmission case. This is why Liberty offers their upgraded front countershaft bearing support mod for the TKO's. Of course if you can't hook up the case load falls off proportionately.
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Originally Posted by Anthony
Chrysler had Borg Warner design a new tranny for the Viper's introduction, which was the T56.
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Again I can't recall with absolute clarity but I believe GM may have first used the T-56 design in the Camaor and Firebird offerings before the Viper deployed it. Additionally the Corvette used a special T-56 for their line.
The Viper T-56 was a special T-56 also. The mainsheet was given some Vitamin C because of the very high torque the V-10 produced. That Viper mainsheet and several other internals were desirable upgrades for extreme service applications until the Magnum version of the trans became a production item and made most of the super duty or similar parts came in the T-56 Magnum offering as standard.
Quote:
Originally Posted by Anthony
Using the Muncie and Toploader as benchmarks, I think all current street 5 and 6 speeds are basically wide ratio 4 speeds with 1 or 2 overdrives. I can only think of one true street close ratio 5 speed, and that was the old Doug Nash / old Richmond Gear 5 speed, where 5th gear was 1:1, and all the gear spreads were truly close ratio.
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I would agree again with two comments;
The Rockland gear folks offer several different ratios for their Tranzilla version T-56 that they claim is 1000 ft/lbs capable. The standard T-56 is offered in either a 2.97 or 2.66 first gear, consistent with your wide ratio observation. The Rockland Tranzilla T-56 gear sets are available in 2.98, 2.71, 2.68 and 2.29 first gear ratios with correspondingly nicely spaced 2nd, 3rd, 4th, 5th, and 6th gears. The 2.29 first gear, gear set is a to die for package — really nice gear spacing! Not surprisingly a really nice (high) price point.
The second comment is that while the old Doug Nash / Richmond 5 speeds do have a 1:1 top gear they are not as strong as the T-56 alternatives. Their gear selection is quite broad however, I want to say they are basically wide ratio selections. If I remember correctly Richmond rates the transmission somewhere around 500 ft/lbs of torque. Again this is not a problem unless you hook up.
Ed