450C Deere w/loader

Roy Suomi, I asked for help diagnosing a transmission/shuttle issue back in December and you replied with a diagnostic instructions. The crawler got shuffled to the bottom of my to do list for a while, so sorry for the long delay in replying. I have a pressure gauge in the test port under the bung between the brake levers. Doesnt matter where the shuttle is or what rpm, pressure gauge reads about 30psi all the time. Shove the clutch pedal in and pressure goes to 170psi at 800rpm and 200psi at 1800rpm.
just to refresh crawler pushes well in 1st gear but wont push in any other gear and struggles to get moving in 4th.
 
I have a 450C and three 480B forklifts. Do you have the tech manual for the 450C? In that era, Deere used a planetary reversing gearbox unit for several machines using hydraulic clutches. I don't have my manual in front of me. Maybe the crawler is slightly different. The pressures must be tested for proper drive and reverser performance. Hydraulic clutch discs and plates could be worn. Have the oil and filter(s) been changed? Is the undercarriage and drive in decent shape, - no excessive drag? Also, check if there's a mechanical disconnect clutch at the flywheel. I had one forklift which would slip in high gears and found that the disconnect clutch was defective, nothing wrong with the trans. I'm curious and will review my tech manual for you.
 
Did you check in Archives ? I'll bet I put half a dozen tips on the 450 HLR transmission adjustment. 30 psi isn't enough pressure to overcome the weight and rolling resistance of that machine. Shoving the pedal down slightly tells me the pressure adjustment in that left side [ by the clutch pedal] rubber bung needs tweaking. Turning that adjustment nut in that hole clockwise will raise the pressure without pushing the pedal. Should be 170-180 at half throttle. Further adjustment will get the speed of shift where it should be.
 
You may have a broken roll pin under the transmission case that controls the hydraulic part of the HLR transmission. If you decide that is the problem, once the top cover is off, Remove rear oiling line to diff gears then slip off the E clip to remove the linkage from the control valve. Then take out the 2 - 5/16 bolts holding the top valve section to lower section. save or replace the o-rings between the 2 sections. You will be able to see if the roll pin is sheared or partially sheared when you hold the lever for the clutching valve while moving the clutch pedal . Should be very little or no movement at that lever.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top