I have a 2001 Gradall 534c6 telehandler with a pile of hours but does the job around the farm so really not interested in upgrading for 15hrs of use each season. I have a couple problems currently. 1st problem is the speed which is about 3 mph tops going forward, reverse just a bit better but not much. Yes, I have the left side inching peddle all the way back. I have the traction control peddle back also. 4x4 switch is also off on dash. Hydraulic fluid is 2/3 up on site glass so is fine. My mechanic that has been trying to troubleshoot it says it could be a micro safety switch somewhere near the back of the boom on the frame but all I can see it the back up alarm. He said this micro switch may be bad and he is thinking that the machine thinks the boom is extended thus keeping the machine in safety slow mode. My 2nd problem is when I use the blinker shift lever to the left of steering wheel to go to reverse to forward or forward to reverse, the delay is quite long as you could have a cup of coffee before it reacts to either forward or back--it does eventually go but foot accelotator pedal has to be to the max to get it moving to it's 3mph! Any suggestions or past experience or know how to figure it out would be greatly appreciated. I guess I am just waiting to hear from that old gradall mechanic that knows exactly what I am talking about and to point me in the right direction---in which I would like to get there going 10 to 15 mph! It is a fully hydrostatic machine but in 2wd it should be able to obtain this speed is what I have been hearing.. Thanks, AlleyCat
we had a Gradall 544,4x4 with 3spd transmission, had a Detroit 4-53N in it..completely ball-less unless you pounded the throttle.It was geared real slow from the start,unless you got it up in 3rd gear wide open it might do 7mph downhill..it was made for slow speed around the job site,Detroit loud as hell even with new muffler.As far as your boom switch,maybe try to bypass it? look for the wiring going up into the boom where a switch might be,try to disconnect it or connect just to prove it out..no boom switches whatsoever on our old gradall
I have a JCB that acts up like that on occasion. If the transmission is shifted electrical look for a bad or corroded fuse, connector down by the trans etc. When mine gets funky it's either no juice to the shifter or voltage to the trans that tries to engage solenoids in the wrong sequence so it's not apply the right clutch packs to be in one gear. Almost like two gears at once. Hopefully that will give you a direction to look.