Cat Lift Trucks (& Caterpillar) DP70:
Transmission Stuck in Second

I have a 1996 DP-70 that is does not automatically shift from first to second. If the selector is in 2 speed mode it will always start in second gear. If the selector is in 1st gear only it will operate only in first. I have changed the high/low solenoid the computer and the pulse generator and nothing made a difference. Serial# 9CP005500. Any help would be great. The fluid level and filters are all good. I wondering if something in the valve body may have a common issue. Thanks
  • Posted 11 Dec 2014 07:22
  • Discussion started by travis_s
  • Colorado, United States
Showing items 1 - 14 of 14 results.
I have the schematic, looking for the LED flash codes really. I appreciate your help. [email address removed]
  • Posted 13 Oct 2015 01:45
  • Reply by 6X95
  • Virginia, United States
Last week i had a gc70k stuck in 2nd. Make sure your relay is correctly plugged or properly routed if it it is bypassed it will run in 1st and will not shift. Red light flash is a problem with solenoid. I cannot copy my page i have but it is useless anyway. Ill find you the wiring fiagram. Give me your email i will send you the pdf.
  • Posted 13 Oct 2015 01:32
  • Reply by alexlift
  • Quebec, Canada
The unit was stuck in 2nd. I replaced the relay, that had filled with water. The machine now starts in 1st gear but will not shift to 2nd. No matter where the rabbit turtle switch is the unit remains in 1st gear. The speed sensor has been verified along with the wiring. I have the red LED flash that I'm trying to determine what they indicate.
  • Posted 13 Oct 2015 00:31
  • Reply by 6X95
  • Virginia, United States
we are close, the problem is most likely to be your relay. 85-86 is your signal to activate the relay 30-87 are your current
  • Posted 12 Oct 2015 23:59
  • Reply by alexlift
  • Quebec, Canada
The unit came in stuck in High(2nd), After determining the relay had failed and replaced, It will now not shift to 2nd. It is in 1st gear.
  • Posted 12 Oct 2015 23:54
  • Reply by 6X95
  • Virginia, United States
are you sure it is stuck in first speed. when things fail, it will be stuck in second speed. do you have the serial of this machine.
  • Posted 12 Oct 2015 23:45
  • Reply by alexlift
  • Quebec, Canada
switch is on the right hand OHG upright, switch tests good, Doesnt matter where it is set at.
  • Posted 12 Oct 2015 23:37
  • Reply by 6X95
  • Virginia, United States
is your speed selector working, depends on the year the switch could be on the right pillar or left of the hydraulics lever.
  • Posted 12 Oct 2015 23:28
  • Reply by alexlift
  • Quebec, Canada
Cat GC70K It does have the resistor and relay. They are functioning, the trans is in 1st and will not shift. Checked the speed sensor all is well, curious on the LED flashes, green stays on, red flashes one long, one short, repeats two times then two short.
  • Posted 12 Oct 2015 22:43
  • Reply by 6X95
  • Virginia, United States
usually it is a fault with the shift solenoid. what forklift do you have. does it have a resistor and a relay for the second speed?
  • Posted 12 Oct 2015 14:17
  • Reply by alexlift
  • Quebec, Canada
I am interested in the LED lash codes as well, anyone? Green continuous with key on, red flashes twice.
  • Posted 2 Oct 2015 00:09
  • Reply by 6X95
  • Virginia, United States
look on the transmission controller and see what the lights are doing? There should be 2 led lights, if there is any problem they will be either solid or blinking.
Look and come back and tell us what is happening there.
You will have to remove the cover to see the lights.
  • Posted 16 Dec 2014 04:55
  • Reply by swoop223
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
[email address removed]
  • Posted 16 Dec 2014 01:03
  • Reply by travis_s
  • Colorado, United States
I need a email address. I think I have so information on your system.
  • Posted 15 Dec 2014 13:29
  • Reply by shovel_fx
  • Illinois, United States

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