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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: krp33 on January 27, 2010, 09:59:26 am
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I have an 86 chevy 1/2 ton truck with a rebuilt 700R4 transmission. The transmission shifts fine but a little soft. There is nothing mechanically wrong with it now. I am planning on installing a Fairbanks superior K700-R4-V shift correction kit with the 0.471 boost valve. Does any body have any experience with this kit? I am also thinking about installing a corvette servo at the same time. What are some opinions on this mod? Will the part throttle shifts be to harsh? I don't want neck snapping shifts, just clean crisp positive shifting.
thanks.
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I have corvette servos in my 700. Mines heavily modded, so I can't tell what they do alone. I like my tire chirping with a side of whiplash. ;)
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I recommend putting the Vette Servo in.
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Capt, isn't that for a more positive 3-4 shift? I know it has a bigger bore for more line pressure or something...
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They are for the 1-2 shift also. I have one in my 03 yukon its a 4l60e but the same as a 700 pretty much and the vette servo was one of the best mods ive done.
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Good for all shifts.
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So shift kit + servos = super pos. shifts, right?
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yes.
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Use a trans-go kit. They are designed to make not just shift feel but actually better hold apply pressure and volume. The servo piston kit is used to enhance the shift feel when a band is applied. The intermediate band is applied to give you second gear. Try to remember this, a servo is used to apply a band. Since the 700R4 has one band the band is applied by this servo and gives you a 1-2 shift. The enhanced servo allows for positive displacement. Trans go also makes a kit for this.
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Trans-go p/n?
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It depends on what you want to do. Look on their website
http://www.transgo.com/index.html
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i just rebuilt my 700R4 and while i was at it i put a transgo 700 junior shift kit in it and you can tell it has a much more solid second gear. But i have a question of my own now. When i was leaving work the other day i got on it and it shifted 1-2 and when it went for 3 it reved up for a split second and then shifted. I know its doing it because the 2-4 band is not fully releasing when the 3-4 clutches are applying. How do you fix this though. I have heard a new seperater plate will do the job. Is this true?
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It's not because the band isn't releasing. Usually it's the accumulator spring, or the seperator plate is a cracked where the spring is seated.
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It depends on what you want to do. Look on their website
http://www.transgo.com/index.html
Thank you
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After talking with the rep from Superior-Fairbanks I decided to go with the K700-R4-V shift correction kit with 0.471 boost valve, a corvette 2nd apply servo, and their K034 billet 4th apply servo. According to the fairbanks rep, firmer shifts and better holding power in 4th gear for light towing. The shift correction kit is not a race type kit. It will correct some potential problems and firm up the shifts. I'll post my results when I get a chance to install it.
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I installed the shift correction kit, corvette servo, .471 boost valve, and billet 4th apply piston and cover. The kit was easy to install, and performed as advertised. my only problem was that the part throttle 1-2 shift was too firm for me, so I dropped the pan and put a stock purple 1-2 accumulator spring in, and that softened it a little. I am very happy with it. all of the shifts are noticably firmer, but not harsh. The shift points were slightly extended. Good upgrade to a good trans.
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Glad to hear!