John Deere 450B Transmission - Help / Ideas - Please

Backround:

John Deere 450B Turbo Loader with Backhoe

Little over a year ago we bought a 450B that had been sitting for a number of years, but started and ran fantastic. So well, the guy who sold it to us couldn't bring him self to tear it to pieces to scrap or sell for parts. Problem was , as so many that sit , steering clutches went to hell and it wouldn't steer. So we replaced the steering clutches, sprockets, ... etc and it has been working great for the last year or so. (we are using it for dirt work on house we are building)

Problem:...

Recently, the transmission has been giving us some problems, and we are hoping we can get some advice on getting everything sorted out. At first, it would intermittently feel as if something wasn't "right" while moving around some larger rocks and some fairly large buckets of dirt. Then it started to have issues in engagement in reverse while backing up an incline (initially with the hoe attached). Letting out the clutch, it wouldn't move.. eventually it would start to "crawl" in reverse at a painfully slow pace. This small incline was never a problem for the tractor before. We checked the level inside the transmission, found it slightly low, hoping that filling to full would fix the issue. It did not. We continued to have issues engaging in reverse and after a day or two, found the forward gears were beginning to fell weak as well. I've tried to read and understand both the manual and online threads with similar issues and troubleshoot everything in a systematic manner. We installed a pressure gauge per manual instructions and found that the pressure inside the transmission is low. It peaks around 145 PSI and the book specifies a working pressure between 170-180 PSI. The only adjustment for the pressure seems to make the pressure go down. I understand that the clutch pedal serves two functions,.. engagement of the drive clutch between the engine and transmission, and fluid to to the clutch packs inside the transmission. According to the book, I should get a pressure INCREASE as I depress the pedal, instead it drops significantly.

I've uploaded a couple videos on youtube in hopes someone can recognize the issue and help solve the problem or at least help identify it.

First video shows the tractor trying to push a small amount of dirt, in "1" "Low". You can clearly see that the tractors tracks completely stop while it should be easily pushing the dirt forward. The tractor doesn't seem to surge, make any noise, or have it's RPM's bounce like I would assume a slipping drive clutch would make? Maybe my thoughts are wrong on this?

https://www.youtube.com/watch?v=hRtr9qbMPP8

Second video shows the gauge movement, rpms, and clutch pedal movement and effect on pressure. Following the service manual. You can hear us talking pretty good in the video.

https://www.youtube.com/watch?v=9BqFIrTwMvY

We generally never shift out of "1" High or "1" Low, transmission temp gauge does not work. The fluid inside the trans however is clean, and doesn't appear to have been burnt or got "too" hot. I just ordered up a transmission filter.. maybe the filter is partially blocked?

Any thoughts or ideas are very much appreciated. We are in dire need of our equipment as the weather will be turning soon and we have much left to do.

Thank YOU!

Roy will will probably jump in here on this. I have 450C, your pedal is functioning correctly. Pressure does NOT go up when you press the pedal, it goes down. I can also tell you that if your pressure is not 180 PSI your clutches will slip when pushing a heavy load.

Here is copy of the procedure [b:6f23656d70]Roy Suomi[/b:6f23656d70]
Re: JD 450 Clutch Adjustment in reply to Tweeter, 11-19-2006 16:50:42
The steel line is steering..The HLR adjustment nut should be somewhere midway from top to bottom of threads.. OK 1 last time..; first , adjust the clutch bolt to 3 and 3/4" "freeplay" from top of pedal to where you feel the fingers of the clutch contact the throw-out bearing..Back off the adjustment inside the clutch housing rubber plug so the pressure drops off to about lets say 50 lbs. Turn the nut in and watch the pressure guage . It should go to it's maximum pressure then drop off slightly , without pulling the clutch pedal off its stop. If it pulls the pedal off it's stop before it gets to it's maximum pressure , there's a problem in the HLR clutch operating shaft or roll pins..Once you have your max. pressure ,push in the clutch pedal about 1/2" the oil pressure should raise about 5-10 lbs..Now you're gonna have to fine tune that adjustment from there. The speed of shift shouldn't be so fast that you can't shift from reverse to forward at wide open throttle without using the clutch pedal..Optimum pressure for HLR is about 180 lbs operating pressure..

Once I got mine adjusted correctly it made all the difference in the world. Hopefully you have burned the clutches out of it yet...

I couldn't have said it any better than that Suomi guy....

At 145 lbs pressure, it should pull ok and not slip much , just not shift so awful good.. You might have a leak in the clutch pack manifold at the sealing rings.. At any rate, try the adjustment too..

Roy, I've passed that written procedure to a number of different people and in almost all cases it has helped them. I know it's in the manual but it isn't explained quite the same way.

bump?