700r4 upgrades - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DRobb's_85 · 01-04-2012, 10:32 PM

Looking to get the 700r4 rebuilt in my 85 K10, the converter is on its way out and this transmission has seen better days. What are some of the mandatory uprgades for the 700r4? Ive heard of the vette servo, anything else I absolutely have to have? Its going behind a basically stock 350 so it doesnt need to be built for 600 hp etc. Also I'm assuming it already has some sort of shift kit in it as it shifts pretty hard, especially when compared to any other vehicle Ive driven. I dont know if I want it shifting as hard as it does now after the rebuild. Maybe just the vette servo without a shift kit? Already has a stock tranny cooler too..Thanks

beamn7 · 01-04-2012, 11:07 PM

Vette 2-4 servo will increase the shift firmness and the 2-4 band holding power on the
1-2 shift as well as the 2-3 shift since it also acts as the 3rd clutch accumulator. More often than not, I've ended up removing the vette servo and installing the middle of the road servo (there were 3 sizes) depending on valve body modifications.....
There are a multitued of of things that can be done to these trannys. They gained a bad rap in the early 80's but a properly set up 700 can be a great trans. Some of the things I would recommend are:
Alto red eagle 3-4 clutch kit
"The beast" reaction sun shell
30 element forward sprag
10 or 14 vane pump rotor assy
.500 boost valve in the pump
Replace the throttle valve assy in the valve body (these wear out frequently)
Inspect / replace 1-2 and 3-4 accumulator springs (have a habit of breaking)
Grind a 2 flat spots on the pressure regulator valve in the pump or get the updated design valve from GM 9if still available)
Replace the bushings
Replace 3rd accumulator ball capsule assy (have a tendancy to leak)
Use a high quality overhaul kit and converter.
Wouldn't hurt to add a pressure drop type external cooler and run some "lube guard" or "Schaeffer Oil". These aren't your typical "snake oils". They actually work. Many large fleets utilize these....

I may be leaving some items out but it's been a couple years since I did a 700. I would highly recommend obtaining a ATSG (automatic transmission service group) manual for the 700R4, it will be most helpful.
http://www.txchange.com/atsg.htm

01-04-2012, 10:32 PM	#1
DRobb's_85 Registered User Join Date: Oct 2007 Location: Rowlett,Tx Posts: 64	700r4 upgrades Looking to get the 700r4 rebuilt in my 85 K10, the converter is on its way out and this transmission has seen better days. What are some of the mandatory uprgades for the 700r4? Ive heard of the vette servo, anything else I absolutely have to have? Its going behind a basically stock 350 so it doesnt need to be built for 600 hp etc. Also I'm assuming it already has some sort of shift kit in it as it shifts pretty hard, especially when compared to any other vehicle Ive driven. I dont know if I want it shifting as hard as it does now after the rebuild. Maybe just the vette servo without a shift kit? Already has a stock tranny cooler too..Thanks

01-04-2012, 11:07 PM	#2
beamn7 Registered User Join Date: Oct 2011 Location: Wildomar, CA Posts: 466	Re: 700r4 upgrades Vette 2-4 servo will increase the shift firmness and the 2-4 band holding power on the 1-2 shift as well as the 2-3 shift since it also acts as the 3rd clutch accumulator. More often than not, I've ended up removing the vette servo and installing the middle of the road servo (there were 3 sizes) depending on valve body modifications..... There are a multitued of of things that can be done to these trannys. They gained a bad rap in the early 80's but a properly set up 700 can be a great trans. Some of the things I would recommend are: Alto red eagle 3-4 clutch kit "The beast" reaction sun shell 30 element forward sprag 10 or 14 vane pump rotor assy .500 boost valve in the pump Replace the throttle valve assy in the valve body (these wear out frequently) Inspect / replace 1-2 and 3-4 accumulator springs (have a habit of breaking) Grind a 2 flat spots on the pressure regulator valve in the pump or get the updated design valve from GM 9if still available) Replace the bushings Replace 3rd accumulator ball capsule assy (have a tendancy to leak) Use a high quality overhaul kit and converter. Wouldn't hurt to add a pressure drop type external cooler and run some "lube guard" or "Schaeffer Oil". These aren't your typical "snake oils". They actually work. Many large fleets utilize these.... I may be leaving some items out but it's been a couple years since I did a 700. I would highly recommend obtaining a ATSG (automatic transmission service group) manual for the 700R4, it will be most helpful. http://www.txchange.com/atsg.htm



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