97 needs new trans 700r4?
- Thread starter gto4gbr
- Start date
Molson02536
New member
Yes it will bolt right up but it may not last long depending on what the transmission application was built for. The 700R4 was used in many application from S10 Blazers and Jimmy's to Vans, Cars and of course SUV.
The 700R4 is the same as the 4L60E which is what you have in your 1997 Sierra, 4L60 was the new name for the transmission and the E stands for Electronically shift controlled from 1st to 4th and torque converter lock ups.
If you swap in he 700R4 in to your Sierra, you may have to replace the weights & springs on the "Governor". The weights and springs on the Governor are what controls the shift points. Light throttle shifts (depending on what you would call light throttle) should be roughly 15-20 for the 1-2, 25-30 for the 2-3, and 35-45 for the 3-4shift.
As far as mph for WOT shifts, that will vary depending on engine and rear end gearing, which at that point you will be looking for WOT shifts to happen at or near redline of the engine.
When it comes to governor calibration, the springs will affect light throttle shifts (the lighter the springs, the later the shifts), and the weights on the governor will control the WOT shifts (less centrifugal weights will allow higher rpm shifts.) and the TV cable can also play a small part in shift points.
4L60E or 4l80E or any E class GM transmissions are much better in many ways. Here is a short class on the 4L60E on which i think you should stick to and this is why.
The 4L60-E transmission utilizes a line pressure control system during up-shifts to compensate for the normal wear of transmission components. By adjusting the line pressure, the PCM can maintain acceptable transmission shift times. This process is known as "adaptive learning" or "shift adapts" and is similar to the closed loop fuel control system used for the engine.
In order for the power-train control module (PCM) to perform a "shift adapt," it must first identify if an up-shift is acceptable to analyze. For example, up-shifts that occur during cycling of the A/C compressor or under extreme throttle changes could cause the PCM to incorrectly adjust line pressure.
When an up-shift is initiated, a number of things from sensors are sent to the PCM, such as throttle position, transmission temperature, and vehicle speed, are checked in order to determine if the actual shift time is valid to compare to a calibrated desired shift time. If all the contingencies are met during the entire shift, then the shift is considered valid and the adapt function may be utilized if necessary.
Once an adaptable shift is identified, the PCM compares the actual shift time to the desired shift time and calculates the difference between them. This difference is known as the shift error.
The actual shift time is determined from the time that the PCM commands the shift to the start of the engine RPM drop initiated by the shift. If the actual shift time is longer than the calibrated desired shift time, a soft feel or slow engagement, then the PCM decreases current to the pressure control (PC) solenoid in order to increase line pressure for the next, same, up-shift under identical conditions.
If the actual shift time is shorter than the calibrated desired shift time, a firm engagement, then the PCM increases current to the PC solenoid in order to decrease line pressure for the next, same, up-shift under identical conditions.
The purpose of the adapt function is to automatically compensate the shift quality for the various vehicle shift control systems. It is a continuous process that will help to maintain optimal shift quality throughout the life of the vehicle.
Clearing Transmission Adaptive Pressure (TAP)
Transmission adaptive pressure (TAP) information is displayed and may be reset using a scan tool.
The adapt function is a feature of the PCM that either adds or subtracts line pressure from a calibrated base line pressure in order to compensate for normal transmission wear.
The TAP information is divided into 13 units, called cells. The cells are numbered 4 through 14. Each cell represents a given torque range. TAP cell 4 is the lowest adaptable torque range and TAP cell 14 is the highest adaptable torque range.
It is normal for TAP cell values to display zero or negative numbers. This indicates that the PCM has adjusted line pressure at or below the calibrated base line pressure. Updating TAP information is a learning function of the PCM designed to maintain acceptable shift times.
It is not recommended that TAP information be reset unless one of the following repairs has been made:
1, Transmission overhaul or replacement
2, Repair or replacement of an apply or release component, clutch, band, piston, servo
3, Repair or replacement of a component or assembly which directly affects line pressure
Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, the PCM will need to relearn TAP values. Transmission performance may be affected as new TAPs are learned.
Learning can only take place when the PCM has determined that an acceptable shift has occurred. The PCM must also relearn TAP values if it is replaced.
In short and simple, yes GM has put a brain in to our transmissions
Molson02536
thanks for the feedback but heres the over all deal my trucks got just under 200k on the engine and trany its throwing a trans component slipping check engine light every so often my buddy has a fresh rebuild 700r4 and he said if i help him get it out of the truck and buy him a case of beer its mine... first im goin to try to change the trans fluid and see if that solves everything but if it doesnt then i guess free trans is better than no trans right? thoughts comments ideas?
Molson02536
New member
Servicing the transmission will be good, DO NOT DO A FLUSH
Just have the pan dropped and replace the filter and use http://www.castrol.com/liveassets/b...AGING/local_assets/downloads/t/TranSyndRD.pdf . Its what we have been using in all our Transmissions on our tour buses and it's what i have in all my toys with great results. 
As for the transmission, visit a local trans shop and have them do a pressure test to verify proper line pressure. Base pressure at idle in P,N,OD should be around 70psi and around 140psi in R. Max line pressure should be at least 190psi at WOT in 1st or 2nd, 225psi is optimum. If base pressure is low, trans or pump is worn out. If max pressure is low, check EPC solenoid. If reverse is slow to engage, and line pressure does not come up to at least 130psi in reverse, replace the boost valve with a Transgo 0.500" boost valve (easy fix in pan).
Also with the pan dropped, ask the Transmission Tech to raise Line Pressure by turning the torx screw on the back of the EPC solenoid no more than a 1/4 turn. This raises the duty cycle of the EPC and will boost line pressure enough for a firmer shift and reduce the slipping effects between the overlap of gears when shifting.
keep us posted and good luck.
Molson02536
Molson02536
New member
Napa, Auto Zone and Wal-Mart has the Transynd transmission fluid and it's very compatible with the Dexton IN your transmission now so no worries about mixing the two fluids.
Keep us posted and remember, only 1/4 turn on the EPC valve to turn up the line pressure to firm up the transmission. There are other things you can also do that are simple if you like that will wake up the transmission, but will really make it firm and maybe to firm for your liking for everyday driving.
The other great improvements is to Swap out your Servo with Corvette Servo's which gives the Bands a better holding pressure. This servo is a must for any performance, towing, RV/off-road application, but would be a nice upgrade for any 700R4 or 4L60E.
Right away you'll notice faster and firmer 1-2 and 2-3 shifts. This servo will give your transmission 50% more apply pressure, just what you need to keep from burning your transmission up under heavy load situations. The beast thing about this servo is easy to install and can be done with the tranny in the vehicle with a part cost as low as $16.00 from Ebay to $45.00 OEM Dealer price.
Good luck and keep us posted.
Molson02536