I just replaced the clutch in a JD450C with a new 12 inch clutch/pressure plate. I started it yesterday and followed the book on adjusting I think and the dozer still will not move. I wasn't able to get the pressures correct according to the book; however at about 1700-1800 rpms, I added shims to get the pressure to about 175 psi (which falls within the 165-185 range according to manual). I am hoping it is just my errors in adjusting as the dozer still will not move. At low idle, the pressure reads approximately 142 in HLR. Questions: I adjusted the clutch pedal to 3-3/4 inches, then started adjusting the nut inside bell housing to change pressure, I never was able to get the pressure to 165 psi....it was at 82 psi until I added shims. Now it reads about 142 at low idle, should I continue adding shims to get to 165 at low idle? Should I replace the oil pressure regulating spring as it may have lost some of it strength and start over from step 1? My big questions is would the dozer still fail to move if I don't get the pressures exactly correct or do you think I have another internal tranny issue?
They are a very fussy on adjustment. If you have a PTO look to see if it keeps turning when it refuses to move. If the main engine clutch is slipping it will be stopped. If it is turning look to the power shift or gear transmission for your problem. Were you sure the main clutch was the problem when you replaced it. Are you sure you direct drive transmission is in gear. I have seen some very sloppy linkages that resulted in the tranny not being locked in a gear as thought.
I'm pretty positive it was the clutch because when I pulled it, the clutch plate had completed sheared away from the spline and springs were completely chewed off. I just read another post about that I should measure the 3.75 inch clutch travel then adjust the nut inside the bell housing until the pedal starts to move, then back off the nut about 5 turns and begin checking pressures. I just ordered a new oil pressure spring as I added quite a few shims just to bring the pressure. I will take the PTO cap off as well now and look at what you are suggesting. I overfilled the tranny by 2 gallons by mistake. I was thinking I had to add the 22 gallons of hyd oil there as it would bleed over into the left and right side as I drained them to change all fluids. So would over filling it make a big difference, if so, I will drain off some.
Check the transmission drip stick under the seat to see what the level is. Put your transmission in neutral. Right below 3rd gear. Have your H-L-R -N lever in neutral. Start the dozer and place the H-L-R-N lever in R. Then go to H then to L then back to R. You should be able to hear if those clutches are working. I had trouble before with the clutch control rod and it gave me fits before replacing it. Be careful changing parts you don't need.
I know for a fact I overfilled it by 2 gallons. Will that hurt the procedure or the tranny readings...I can easily get underneath and drain off some without hoping making an entire mess. I drained all fluids as the tranny fluid was milky and I just bought this broken dozer....clutch was sheared from springs.
I have no idea if the excess fluid would effect the pressure. Not questioning your putting in a new clutch. There are numerous other parts that also go along with the transmitting of power to the tracks. I believe I would loosen the nut inside the bell housing and see if the ends of the clutch control rod are tight. They are pinned in and if loose will not allow you to adjust the right pressures. Good luck with it. I had trouble a few years ago with mine and it is a PIA to get it right.
Thx Don! I will start back at square one with measurements and all.
Thanks to all the feedback since I've acquired my new (old) toy. I was finally able to make her come to life with adjusting the pressures correctly and am now a happy dozer owner! Now time to work on some of the other smaller issues.
Awesome! After adjusting the clutch and powershift and making it work correctly you are now qualified to take on any repair.