How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jeff Your Own Question
Jeff
Jeff, Mechanic
Category: Heavy Equipment
Satisfied Customers: 318
Experience:  8 year forklift mechanic on all brands hydraulic hose cylinder repair parts source lpg knowledge
25442757
Type Your Heavy Equipment Question Here...
Jeff is online now
A new question is answered every 9 seconds

My hyster forklift will not go into gear.

Customer Question

My hyster forklift will not go into gear. If I lift the front wheels off the ground, then it will engage. If I let the wheels spin while off the ground and warm it up, I can then set it back on the floor and it will work for a while. The fluid level is up to the full line. Any ideas what it could be?
Submitted: 6 years ago.
Category: Heavy Equipment
Expert:  Curtis B. replied 6 years ago.

curtis b :

Welcome to JUST ANSWER heavy equipment. With years of experience, I look forward to doing my best to help. Does the unit have monitrol pedal for f/r ? Or does it have two brake pedals and a shifter on the column? All forklifts have an inching valve built into the control valve. It is controlled either with a brake line from the brakes, or a piece of mechanical linkage that goes from the brake linkage to the valve body. If the inching valve is partially open, the unit will not drive as it should. Did problem come on suddenly or get worse over time.? Let me know. Thank you.

JACUSTOMER-2pe2ygr1- : The forklift has a monitrol pedel to shift to forward and reverse. I'm not sure if the problem came on suddenly or over time. If I had to guess I'd say that it came on after it set for a couple weeks.
Expert:  Jeff replied 6 years ago.
Hello, what is the model and serial number of your forklift? If there is not a tag the serial number is stamped into the frame on the right hand side were the hood shuts or if it is later model hyster it will be stamped into the crossbar in between the mast and the frame on the frame side. Thanks and let me know.
Customer: replied 6 years ago.
The number is stamped near where the hood shuts. That number is D3D9736Y. It looks like there was a tag, but it was removed. The engine make and model is Ford 4-192.

Thanks
Gary
Expert:  Jeff replied 6 years ago.
Ok, it is probably a model H40-50H on the transmission control valve you will find a brake line that goes to it, it is on the front rh corner of the control valve as you are sitting in the seat. There is an aluminum cap with two bolts in it in that area where the brake line goes in. What that does is put the transmission in neutral when the brake is applied by dumping the transmission pressure. Behind the two bolt cover you will probably find the spool is stuck in due to rust or the brake cup is wadded up in there. Check it out and let me know if you need more help.
Customer: replied 6 years ago.
I disassembled the mechanism that you indicated. The spring, spring cap, rubber diaphragm and spool all came out of the bore easily. I cleaned everything well, checked to make sure that it all slid in and out easily and reassembled. The problem still exists.

It feels as if the transmission is slipping. When I put it in gear I have to kind of feather the throttle to get the transmission to begin to grab.

Thanks
Gary
Expert:  Jeff replied 6 years ago.
Ok, the next thing I would do is a transmission pressure check on the forward and reverse clutch packs just to see what we have. I will post a picture of were the test ports are and what pressure it is supposed to run. Thanks
Customer: replied 6 years ago.
I understand that I need to continue to work this problem and I am waiting the next set of instructions.

Thanks
Gary
Expert:  Jeff replied 6 years ago.
Here is the transmission test port diagram and what they are supposed to be in psi.
Customer: replied 6 years ago.
Unfortunately when I print the page or blow it up and try to look at it, it's so blurry I can't make out any of the text. Is there any way that I can get a clearer picture?
Expert:  Jeff replied 6 years ago.
I will see if I can make it clearer for you. Thanks
Customer: replied 6 years ago.
Thanks, that's much better. So as I understand it, I need to test each of these four ports and determine the pressure at 1000 RPM. I see that the pressure is tested either in drive or in park. With the monitrol system, is there really a park setting? Would that just be with my foot on the brake and the monitrol in forward? And for drive, would that be with the forklift moving forward at 1000 RPM?

I'll not get the chance until Sunday to try this out. I have also ordered a manual which may make it easier for you to explain things to me.

Thanks
Gary
Expert:  Jeff replied 6 years ago.
Hello, you will want to elevate the front wheels by tilting the mast forward on some blocks on the outside channel to perform the pressure test. Test in park would be with the parking brake applied, tests in drive would be with parking brake off and brake pedal not applied. Thanks and let me know if you need more help.