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4 speed Mods

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Old Aug 14, 2006 | 03:29 AM
  #1  
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Default 4 speed Mods

Any way to change the 1:1 fourth gear from to a 0.71 or 0.57

Like a OD gear?

Lowest usable gear ratio?

Anyone ever try this?

Sound crazy or make any kind of since?
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Old Aug 14, 2006 | 08:36 AM
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Go to www.autogear.net. They make an overdrive 4 speed Muncie.
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Old Aug 14, 2006 | 04:36 PM
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Thanks not too much info there.
Looking to get better MPG on highways.
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Old Aug 14, 2006 | 04:51 PM
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If I were to try and make the 4 speed muncie an OD unit I'd change all 4 gears to a ratio that the 700R4 or 2004R use. That way it doesn't have an ackward shift feel.
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Old Aug 14, 2006 | 04:57 PM
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Couple different ways...completely change all the gear ratios, or (much better idea) install a GearVendors Under/Overdrive unit. They're very trick, and will essentially make your tranny an 8-speed, giving you a "1st-and-a-half," "2nd-and-a-half," and so on. It shifts using a planetary gear set (like an automatic) to go from whatever gear you are in into the overdrive version of the gear - think of it like having two rear ends that you can switch between however you want. The units are pricey but can be picked up on eBay for under $1000.
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Old Aug 14, 2006 | 05:14 PM
  #6  
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I installed a T5 in my '79 for $1,200.00. Best mod I have ever done. Went from turning 3400 rpm at 70 to 2100 rpm!
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Old Aug 14, 2006 | 05:23 PM
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I have added a Keisler 5 speed OD tranny to mine. Works like a champ.
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Old Aug 14, 2006 | 05:33 PM
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Originally Posted by Eddie 70
I have added a Keisler 5 speed OD tranny to mine. Works like a champ.
Would not go back to a 4 speed.
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Old Aug 14, 2006 | 06:08 PM
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Default Gear Vendors ... ?

I really like the Gear Vendors idea. Has anyone done it or have pictures?

carbster
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Old Aug 14, 2006 | 07:02 PM
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Originally Posted by carbster09
I really like the Gear Vendors idea. Has anyone done it or have pictures?

carbster
Looks rather heavy and I'm not sure how well it'd fit in our transmission tunnel. I'd rather just go with a transmission designed with an overdrive.

The gearvendors idea has been around since like the 50s/60s. Old Triumphs came with those things.
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Old Aug 14, 2006 | 07:16 PM
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Check out the cost of the Gear Vendors. It is about the same as an OD tranny. I doubt it will fit in the trans tunnel. It is pretty tight back there.
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