John deere 450c grinding gears with clutch depressed

[Bhedge]

I have a john deere 450c serial no. 450cc 307819T I believe it to be a 1978 model year. I have a tech manual
TM1102 I have adjusted clutch pedal per the spec 3 3/4" free play and hooked up pressure gauge to set HLR to spec. At idle I only read 130psi on a gauge hooked up to test port in bung hole. Problem is gears grind going into 1234 with clutch depressed some times. I have to shut machine off to get into gear start up and it's good to go for a awhile. Dozer stop when using clutch. Example
1st gear clutch to the floor HLR in L let clutch out dozer moves and stop when clutch depressed. Stop shift HLR to N trying switching to second with clutch fully depressed it may go or it might grind. So could my clutch disk be stuck to fly wheel or pressure plate. Also should the pto shaft out the back quit spinning with clutch fully depressed iknow pressure on HLR is not right also but it is working right now and that will be my next question after I figure this out.

[Jim B]

You don't say if you did the entire procedure to adjust the H-L-R clutch valve as well as the clutch pedal (even if the pressures are off a bit)?

[Bhedge]

I set the free play to 3 3/4. Than I hooked gauge up and at idle the gauge read 130 psi HLR was in H and 1234 was inbetween 3-4 . I turned the 1/2" nut in the bellhousing clockwise but the gauge never increased. The more I turned it clockwise the pedal started to pull away from the stop on the bellhousing so I quit because I didn't think that was right. So im not sure what to do now. I changed the filter but not the screen by track yet. Fluid was clean. I know that may not matter but I didnt think it was a concern yet ntil I could get the gears from grinding since it was kind of two different systems. Let me know if I'm wrong. It would not be the first time just ask my wife. If I increased the idle to 1800 rpm pressure would go to 150-160. Than when I would move the HLR from H to L or to R the pressure would drop down to like 50 psi and than jump back up. It would take about 3 to 4 seconds to do that and that is at 1800rpm. I have not messed with the pressure valve yet with shims. Not for sure what's under there. Didn't want to get to fsr before I really messed things up. Any guidance would really help.

[Jim B]

I don't have a 450C manual. I have a 450E manual, so I think the info is the same, or very close. After setting the pedal free play it says to tighten the nut until the pedal starts to move away from the stop, then back it off 5 turns. Followed by turning in to watch for pressure rise. I believe you should be able to do the procedure as given even if the pressures are low, recording you results at the points called for in the manual. That should confirm the adjustments are correct for starters.

It is possible there is wear in the clutch disc splines and the splines on the shaft and it might be hanging at times.

[Bhedge]

I tried that tonight and it did not change pressure.
Step one adjust pedal free play to 3 3/4"
Step two tighten 1/2" nut in bellhousing till pedal starts
to just move off stop.
Step 3. back nut off 5 full turns
Step 4. hook gauge up on test port in bung hole
Step 5 place 1234 transmission into neutral position
Between gears 3 and 4
Step 6 start engine and at idle put HLR in high and
Adjust pressure til it starts to fall 5 psi off of it
High point.
Step 7. Tighten nut one full turn

I did these steps and the pressure never moved when I started to adjust nut. I kept adjusting till the pedal was starting to move off the stop on the bellhousing. I quit didn't want to keep going and mess anything up. Should I look Into the pressure spring and put shims to get pressure up? Could pressure be to low to see a adjustment? If I give it throttle 1800 rpm the pressure goes up. Is the pto out put that would say run the winch stop moving when you fully depressed the clutch? Should I drain all the fluid and check screen on the right side of the track? I do have the right compliant hydraulic oil and the level is also correct. Would the valve that adjust how the shift between H L have any affect on any on this? Thanks in advance for any help.

[Bhedge]

Still needing some guidance if anyone can give some more input on these issues. Does pto or out put shaft that would run the wintch turn when clutch is fully depressed? Can the low pressure for HLR in setting the pressure guide be a leak internal or is it wear? what would be some steps to do? Can gears grinding be in tranny on main shaft or is it something that could get better from use? Dozer has set for a few years. Thanks and thanks for the responces i have recieved so far.