I have a 416 cat backhoe that we use around our salvage yard. we used it to clean up around the car crusher and on the way back up to the shop it stoped moving.it was not slipping before this. we checked the trans fluid and it was fine. we changed the trans filter and it still did not move. we checked the trans pump pressure and there is none. any ideas how this happened all at once?
Write the serial number of the machine. Is it an E, F, F2 series machine or is it the latest BHL model? And where did you measure the pressure? You may have an electrical problem.
Cat 416 backhoe Pin# 5PC04698 engine serial# U179404P Trans serial# G72022. Checked trans pressure at the port on top of the trans,under the floorboard access hole.
I can assume that the DRIVE GP-FLEXIBLE COUPLING suddenly broke off. The pump is driven by the torque converter impeller housing, and the torque converter is connected to the engine using flexible coupling. The second possible reason is that the transmission pump simply suddenly failed.
Is there any way of seeing that coupler without removing torque converter housing ?
I think you can't see it without disassembling it.
Isn't there a small plate under the bell housing on the transmission? it might be possible to turn torque and see if it is still attached to engine
Yes, that's right, there is a small plate, but can you see this GP-FLEXIBLE COUPLING there?
I'm not saying you can see it i'm saying turn the torque and see it it will turn the engine. If flex plate is broken torque should spin easy with out turning engine
Was there any noise when it quit? I would think if you broke the flex plate it would sound like a garbage can full of nuts and bolts. Have you checked the nuetral switchs and wiring?
we are kind of thinking its an electrical problem. i am going to check the solenoids on the trans this week. thanks for responding. i will let you know what we find.
Do you have an electrical schematic.?
(B) Pressure tap for pump. (D) Pressure tap for torque converter inlet. If the problem is in the electrics, then the question arises, where did you measure the pressure in the transmission? The transmission pump pressure should be measured at point B. Is that where you connected the pressure gauge? If you measured at other points, then this is the pressure in the Forward or Reverse couplings. You just initially wrote about the transmission pump pressure, that it is not there. (A) Pressure tap for reverse clutch. (C) Pressure tap for forward clutch. (F) Pressure tap for lubrication and cooling.
i checked the continuity in the control valve solenoid coil and it is good. but when i wired the solenoid to direct 12 volts i hear no clicking and i cannot feel any motion when i put my hand on it. i did not have the right wrench with me to remove it,so i could see if it was working. could this solenoid be stuck ? Is this the solenoid that the switch on the shifter and the bucket control operate ?
Did you check the wire to solenoid for power and ground? did you see what happens at plug when you push one of the buttons
A lot of times, you can check a solenoid by seeing if it’s magnetized with a screwdriver, when it’s activated.
Yes i have power and ground at the plug when i push the button. I didn't check for magnetism at the solenoid. I will check that. thanks. If that solenoid is not working the machine should still move right ?
Depends on what the solenoid in question operates. Haven’t read through this whole thread but you indicated that it’s an electrical issue. Generally, if the transmission is working, it gives signs that there is a problem coming up. The way you describe it suddenly quitting, with no noises, to me indicates an electrical safety issue. Could be a solenoid shifting issue also.
It's also worth pointing out that even if the solenoid coil energizes when powered it might be the case that the spool inside the valve body is not moving for whatever reason. A loud click is what you should be looking for.
that is what i am thinking .there is no noise or vibration when you work the switchs. thanks