I have a 1993 GMC Sierra. The truck has been running fine and the tranny only has like 1500 miles since rebuild. The problem is last night I pulled off and the truck would not get out of first, I looked down and realized speedo was not working. The question is: Does my truck have a 4l60 or 700r4? What would cause the speedo tostop working,and in turn would this be why it is not shifting??
I will try and clear up any confusion about the different model designations.The trans was first introduced as the Turbo Hydramatic 700 r 4.Later in the evolution of that family,it had improvements made on it by the factory engineers,and they redesignated it the 4L60 model.The 700/4L60 uses a throttle valve cable as a mechanical indication of the throttle position....to the trans.The TV cable regulates mainline hydraulic pressure inside the transmission.This model also uses a governor as a road speed mechanism.It is responsible for the TIMING of the upshifts,and is responsible for the trans being in first (low) gear from a standing start.In 1993,the 4L60E was introduced to the lineup.Same trans as the 700/4L60,but now it is totally electronic,and totally controlled by the PCM (Powertrain Control Module) based on electrical inputs/outputs from the trans,throttle position sensor,road speed,etc.The engineers took the 700/4L60 and did away with the governor and TV cable,made it totally electronic.Early 700's had a mechanically driven speedometer,while the later 4L60's and E's had an electronic speedometer.1993 was a transition year.I have seen both,the 4L60 and the 4L60E in 1993 model trucks,it depends on the month of the manufacture of the vehicle.Your truck could have either,or.The way to visually identify the difference is........on the driver side,the 700/4L60 trans case will have a round,black,governor cover,about 3 or 4 inches in diameter.The 4L60E case does not.The 700/4L60 also has the TV cable mounted on the passenger side of the trans case,and it routes up to the throttle body/gas pedal/accelerator linkage.The 4L60E does not.Recently,the 4L65E and 4L70E versions have been put into production.Based on your description of the malfunction symptoms,i would be inclined to say yours is probably the 4L60E version,because the speedometer malfunction occuring at exactly the same time as the shift malfunction.On a 700/4L60,the speedo malfunction would have no affect on the upshifts,the trans would operate normally.On the 4L60E,a speedo malfunction would likely cause no upshifts.You should still visually verify by the governor cover,or lack thereof,on the side of the trans case.It could just be a speed sensor malfunction if it has the "E" model.If so,it would have set a trouble code which can be accessed with a scan tool or a code reader.Hope this eliminates any confusion.Good luck!!
The brake fuse is the problem. I know it souns crazy, but trust me...
I have a 1994 chevy silverado 2wd with a 4L60E trans. i have the same problem. it just started it last night. i hooked up a cd player in the truck. would that have anything to do with any of the sensors?
5,485 views
Usually answered in minutes!
2003 GMC Sierra K1500 speedometer read faulty -- Reads in excess of 120 then gradually gets back to reality Is now doing more often as the weather is getting colder
2000 gmc sierra speedo doesnt work and wont shift out of 2nd
2000 gmc sierra speedo doesnt work and wont shift out of 2nd
eratic shifting from 3rd to drive rpm rises speedo drops to 0 but fluctuats radicly or bounces from 0 to 10mph while truck deserats from 50mph on down.
×