has anybody had any exprience with a shift kit on a 700r4 tranny. i'm trying make this thing durable for many years of service. i got everything covered as far as the weak points of this trasmission and then some, but i've heard mixed stories of shift kits ending the life of a transmission early. it's a daily driver and doesn't see the track and the motor is pretty mild and will end up with around 350hp/350trq when i'm done. i've also heard of people swapping out the valve body instead of installing a shift kit. does anybody have any suggestions?  

I never heard of a shift kit wearing out the trans. faster but I heard they may last longer do to more press on the clutches witch will result into less slippage and wear.  

It is not a good idea to install a shift kit in a trany with a lockup converter.Go threw it the right way and do the pro mods and itll last a long time on the dd street car.  

The only thing shift kits will do is increase line pressure and in turn firm up shifts and WILL NOT decrease tranny life but most likely extend it due to less slippage. My recomendation is Superior Transmissions kits.  

When giving advice on a subject its a good idea to have the forknowing of the issue.A 700R4 creates a lot of heat when in overdrive.As we all know PRESSURE creates heat @ a molecular level.In a 700R4 it is detromental to drill out the return hole from the pump to the case to allow this fluid pressure to release as well as to gain the added volume to the bands 4 cooling with hi HP. Secondly when the converter locks,it gives that much less area for the fluid to retreat.The fluid is routed past the converter from the cooler directly to the drive planetary and clutch-packs.So in a NON-LOCKUP trany a shift kit is no issue,but in an O.D.lockup it can cause unwanted stresses on seals,and high operating temps.WE DONT WANT THAT NOW DO WE.  

Maybe my brother and myself have been doing it wrong for the past 30 years then.  

Shift kits are recommended regardless of lockup or non-lockup applications.  B&M has shift kits in its 700-R4's...TCI has shift kits in its 700-R4's and 200-4R's.  My best friend in high school installed a shift kit in his 700-R4.  I installed a shift kit in my 200-4R (a rather harsh one at that).  The best transmission guy in the area, as well as another highly touted high performance transmission shop both recommend shift kits in 200-4Rs and 700-4Rs.

I've had experience with both of GM's OD's from the 80's...I've had shift kits installed in both...I've driven both hard...never had a single issue with them.

It will extend the life of the transmission.

Temperature will not increase with pressure when we are talking about an incompressible liquid.  Sure if its compressible temperature will increase...but transmission fluid is incompressible...which is why it works.  Heat from transmissions is created from the friction of the clutch packs.  Its a simple first law thermodynamics approach.  dU = dQ - PdV     PdV = 0 since there is no volume change.  If you chose an adiabatic system (ie no heat transfer) then you are left with dU = 0  Without volume change there is no internal energy change.  Without a change in internal energy there is no temperature change.  So the rise in temperature does not come from increased line pressures...but slippage in the clutch packs (ie dQ).  

Ok,so u want to pick my statement apart and focus on 1 piece of the big picture thats fine.And if your going to try to tell me that if B&M or TCI can make a buck on a "performance part" irregardless to the longevity of the overall outcome,PLEASE..! All companies are in to make money.And by the way 700R4's havent been in production for 30 yrs.Earliest I can find on'em is 81'and that was behind a 5.7liter diesel.No cars till 84'.So that post MUST b refering to 350/400 HYDRO's.And a shift kit WILL extend the life of a 350/400 turbo hydro.Never said it wouldnt.On any auto,more pressure on the bands is less slippage and less wear.But in the case of the R4 it can cause other issues without those other mods being done.So call me wrong,my cousin been buildn'm that way since he graduated GM tech in 1983.never had 1 fail yet.BY the way they dont sell shift kits for the 700R4.They sell TRANS-PAKS.Big difference.  

Sure they'll offer up kits to make a buck...but why would the jeopardize their OWN transmissions that they have to make money on???  TCI offers 700-4R's that they have to honor a warranty on that has a shift kit already installed.

Face it...you are in the VAST minority here.  No one except you believes that a shift kit will cause problems...not professional transmission guys, not aftermarket transmission companies, not the guy down the street, not Car Craft, Hot Rod, Chevy Hi-Performance, or a number of other publications I've read that have never once said "do not install a shift kit if you have a lockup converter"...no one but you.  You've already got two people who have PERSONALLY installed shift kits in lockup transmissions with no problems.  You've got nothing to support your argument.  You've never done it so it must be bad???  Give me a break.  Find some PROOF that it shouldn't be done.  That doesn't mean the guy who graduated from some tech school in 1981...find a reputable publication that specifically states "a shift kit will destroy or cause premature failure of your lockup equipped transmission"  Burden of proof is on you since you're going against the status quo.  Otherwise you're just promoting a made up myth.

And http://www.transgoperformance.com/gm700r4.htm says you're wrong about not offering shift kits.  

And talk about tearing apart someones post...you criticize the guy for being off by 5 years and its ok...yet I correct a MAJOR flaw in your argument and I'm nit-picking???  

You specifically stated that increased line pressure would increase the temperature of the fluid causing failure.  Thats a major flaw buddy.  Puts a MASSIVE hole in your argument.  Now you have nothing to support any claim of shift kits causing failure...except your cousin has never used them and never had a problem.  Gee thats all the proof anyone could ask for...if you're in grade school.

Sorry to be such an ass...but com'on...people have used shift kits in these transmissions for decades now...might want to come with some solid proof to make such an outrageous claim...especially when the physics behind your reasoning is shown to be flawed.  

To clarify what I said earlier I've been in and around the transmission business for that amount of time not the introduction of the 700 R4.  

Thankyou CSIROC! To clarify what I said earlier I've been in and around the transmission business for that amount of time not when this unit was introduced.  

Oops sorry about the doubl post.  

Cant find anywhere on the posted info for TCI's site were they use a shift improver kit.They use there own valve body castings,and pumped up servo's.Their tech told me back in 95' when we put TCI streetfighter 400T in my bros tubbed Chevelle that they dont usem in there tranys,they do all pro mods to rule out possible issue. That must be made up too though so you might give them a call so it can be confirmed.After all its been over 5 yrs so a lot can change right.The trany fluid factor,ok I fine,Im wrong.Big HP requires Big mods.  

Must have missed this then

"TCI® Trans-Scat® kit installed for firmer shifts"

I can tell you from my personal experience building a 200-4R that the modifications involved with the "Trans-Scat" kit were the exact same as the off-brand shift kit my best friend used in his 700-R4 (91 Z28).

Things may have changed over the years...it was about 5 years ago that my best friend put in his shift kit (700-R4 91 Z28)...I only put mine in two years ago (200-4R 68 Cutlass).  Before that I didn't pay much attention to transmissions...just figured I'd let the professionals take care of it.