New gears for an automatic
Thread Starter
Pro
Joined: Jan 2003
Posts: 577
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From: West Plano TX
New gears for an automatic
TCI makes lower first and second gears for a t400. Does anyone know if anyone makes them for a 700? I need a trany rebuild and would like to change those gears while in there and not have to drop the $ on ring and pinion.
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Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: New gears for an automatic (Spare Time Toy)
Thats funny. Your the first person I have ever seen wanting to go with an even wider gear ratio split on than the 700 already has. Most people agree that the 700R4's extreme gear ratio difference between 1-2 and 2-3 cause the engine to drop well outside torque/Hp curve peaks. This is why almost any smallblock car runs faster with a TH350 than with a 700R4. In fact, I have been looking for a close ratio gear set to replace the planets on my 700R4 for years, and there are not many made. I have been considering replacing the 700 with a 2004R built like the buick turbo people build them. The 2004R trans has a much closer gear ratio spread which is a big help to the GNX's performance.
Trust me...a wider gear ratio trans will not help performance at all. Change the gear instead.
Trust me...a wider gear ratio trans will not help performance at all. Change the gear instead.
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: New gears for an automatic (Spare Time Toy)
Yeah why would you want a lower ratio than the 700r4 already has?
The deep first gear ratio (3.06) in the 700 means that you dont have to run as much rear gear, but it also means youll suffer from a greater rpm drop from 1-2 shift. Thats not good for ETs.
The deep first gear ratio (3.06) in the 700 means that you dont have to run as much rear gear, but it also means youll suffer from a greater rpm drop from 1-2 shift. Thats not good for ETs.
Advanced
Joined: Nov 2002
Posts: 77
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From: Calimesa California
Re: New gears for an automatic (Spare Time Toy)
If you use a (apx. 2,400 rpm stall) 9.5" A.C.T. or Vigilante, this will "hide" the big drop from 1st to 2nd gear. No need to go to the 2004R, unless a tenth in the quarter mile is worth that much to you. A properly matched TC will do more than any single modification (naturally asperated that is). John Kilgore makes wide & close ratio gear sets for the TH400. The 700R4 will do what you want when properly setup, without the expense of changing gear sets or transmissions.
