Gradall Telehandler problems
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Joined: Oct 2002
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From: The Big, Oregon
Gradall Telehandler problems
My boss is leasing a fairly poorly maintained Gradall 534d-42, and I'm doing a few quick cheap repairs to keep it operational. My main concern is that we drive it all over town to install sites, and it's slow, about 6mph. Everything I can find says that thing should do 16 in 2wd. It did have a bad 4x4 switch, so I changed that out and can now hear the valve click, but it only picked up maybe 1-2mph.
It'd be really nice to get to a job site in 10-15minutes instead of 30-45.
It'd be really nice to get to a job site in 10-15minutes instead of 30-45.
Thread Starter
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Hotshot
Joined: Oct 2002
Posts: 18,488
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From: The Big, Oregon
Well, this one doesn't have a transmission -per se- it's all hydraulic. Diesel engine with a big hydraulic pump on the end of it, three hydraulic drive motors: One for the front axle, one at each rear wheel.
I'm starting to think it's a problem with the 4x4 selector valve. From what i can gather, in 4x4 it sends fluid to all motors. In 2wd, it only sends fluid to the front motor, and loops the rear motors. I was messing around with it today, and with the parking brake on (spring applied/hydro release within the front axle housing) I got it to spin a rear tire. In 4x4 it spun it a little more easily and also overpowered the brake. I didn't try the hydraulic traction lock, maybe I will next time I mess with it.
I'm starting to think it's a problem with the 4x4 selector valve. From what i can gather, in 4x4 it sends fluid to all motors. In 2wd, it only sends fluid to the front motor, and loops the rear motors. I was messing around with it today, and with the parking brake on (spring applied/hydro release within the front axle housing) I got it to spin a rear tire. In 4x4 it spun it a little more easily and also overpowered the brake. I didn't try the hydraulic traction lock, maybe I will next time I mess with it.
Post Fiend
Joined: Jan 2005
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Ok you have hydrostatic drive. Usually this type of drive has a limited speed range and they provide two or three mechanical shifts.
However you may be on to something with the two/four wheel drive as there may be a lock out to prevent higher speeds in four wheel drive.
Do you have four wheel steer? If so then there may be a lock out also allowing road speed in two wheel steer only.
However you may be on to something with the two/four wheel drive as there may be a lock out to prevent higher speeds in four wheel drive.
Do you have four wheel steer? If so then there may be a lock out also allowing road speed in two wheel steer only.
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Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
It's a single steer, and from what I understand it just goes slower in 4x4 due to having more draw off the system. In 2wd, it loops the motors on the rear axle, and only supplies pressure/flow to the single front axle motor.
