Hi All- I'm new to the site and figured no better place to get some insight. I just recently purchased a 1996 Hyundai HL 770 with around 10,000 hours on it. The transmission has some issues. Some I have fixed and some still trying to figure out. Basically where I am at now is 1st and 2nd gear(f/r) both work, but will not fully engage into gear until it surges 2-3 times and finally grabs the gear. But regardless of what i do, the machine will not shift beyond 2nd gear. The speedo does not work and I have found what seems to be a sensor on the side of the tranny with broken wires leading to it. Is there such a thing that if no speed sensor the tranny will not shift into 3rd or 4th? Thanks for any insight or ideas. s
Your transmission should be a ZF. So yes, if your speed sensors are broken you will loose 3rd and 4th gears.
Yes it has a ZF Transmission. I have found sensor on the left side of the transmission with wires cut. Is there multiple sensors?
Fixed the wires and now I have 3rd/4th gear and a working speedo. Thanks!!
Now that we got some snow to push around and have used the loader, i have noticed it seems to move around really slow. Like max speed in 3rd is 11 mph and 4th is 13-14mph downhill. It actually will not carry itself in 4th with any slight uphill, and i mean slight. What could be some of the issues causing this? Shouldn't this loader move around in 4th 15-20 mph?
Not sure what exact model you have. I found a spec sheet for a HL770-7, and it says max speed forwards is 23.6mph. That's probably on flat ground, and no load. Did the machine ever go faster then your current speeds? Is the machine still going into 3rd and 4th gears? Could have a weak transmission, or torque converter. Change your transmission filter first and cut it open and check for debris in it.
Funnily enough we've got a 770-7 in our workshop right now. It actually moves along quite well (when the crappy cummins engine is working). *ducks for cover* You should start by doing a stall test which will immediately tell you whether the problem is in the engine or the power train.
I got the machine this fall so its new to me. It is a 1996 HL 770. Not a -3 or -7. Initially I had cut the filters and changed tranny oil and all looked good when i got it. It does seem like the brakes are stuck on sometimes. Is it normal for the wheel hubs to be pretty warm after some normal use?
There is no tach so I would need one. I have never done this test but have read up on it. You might be on something as the machine just seems to not want to move.
Bringing this thread back up. Snow season here so back on diagnosing the low travel power. I did find that the brakes on both axles were dragging, but even with the brake lines disconnected to each axle, the loader just did not have any power to move along at what i would call a normal speed. My next diagnosis to me would be a faulty TC. My question is there test ports somewhere to test the pressure or any other way to test? Or if anybody else has any other ideas please chime in. Thanks
Hello, how much oil is filled in t/m? Oil level needs to be set with engine idling. Correct dip stick fitted? Oil level should be around 50 mm below center output shaft. What is stall speed of engine? Shift into 4th gear and step on brake and gas pedal. What engine speed then? br Bigbert
Well part of my problem is there is no rpm gauge but working on getting the tool so we can check rpms and do the stall test. I'm not sure if it has the correct dipstick. After pouring in recommended amount it has continued to show way over full.
brakes fully releasing? does it have an trans cut out pedal? could be stuck down or not fully up causing low breakout force and slow travel speed?
I work on a 770-7, has digital dash with rpm guage. Will run up above 2200rpms & has little trouble getting there with almost 13k hours on the clock.
No trans cut-out pedal. Yes the brakes are sticking but if i disconnect the brake lines it and run it, it helps it get around a touch better, but still a long ways from how it should move around.
Hello Jonespond, are brakes hot after longer travel in 3rd/4th? If not come back to oil level in tranny. Make a rough check with engine idling: Oil level should be around 50 mm below center output shaft. I doubt the TC is faulty as these parts are more than robust. However, there are two ports on t/m to measure TC inlet and outlet pressure. Could send you sketch to your email address: Please contact me [email protected] br
Email sent. Thanks
it may not shift in to 3 or 4 is not enough engine speed, pretty common with older komatsu's
troubleshooting guide attached Attached is some troubleshooting for HL 770 wheel loader If you need any Document for this loader let me know