jd450g cranks right up runs great pushes great for about 30 min then have to use 2nd gear bcause 1st wont do a thing how bad can this be and will i ruin anything else by running in 2nd and countinuing work
I know this was an old post but just going to reply incase someone can use this information. Just got done fixing a JD 450G Problem was it would move a ways then come to a stop in any gear. I blocked the machine up and ran the tracks with a paint spot on the tracks and almost exactly 11 complete revolutions. Put a pressure gauge on it and noticed the pressure dropped about 2 lbs a second while the tracks rotated until it got low enough to stop. Pulled the back cover from the transmission and checked for broken steel lines and or bad hoses for the brakes but they were good. The trouble was the transmission filter bypass. The housing was scarred inside with the bypass valve so i got some fittings to cap off the bypass and plumb the hoses together to eliminate the bypass temperarily. Ran the machine while watching the pressure guage and the pressure held with no drop so i replaced the filter housing and it's been running fine since. I tried shimming the bypass spring but it still failed. Hopes it helps someone, Ron
Hi Ron and welcome. This is exactly the kind of post I like to see. I don't have that problem with my 450d but I'll keep it in the back of my mind and should something similar occur I'll be sure to check that.
Thanks! The boss had 3 different people look at the dozer and after a ton of money and no fix he was about fed up. I was looking all over the internet and was coming up dry. I also neglected to mention the trans filter light was on intermittently. There were a bunch of sites but the problem was just that one in a million problem i guess. The first guy changed the hyd. pump and pulled the transmission to check the clutch packs....fail. The next 2 guys pulled the transmission and one changed the control valve and the other adjusted the linkages a couple times....fail. I kept telling the guys to figure out the filter light problem and they might fix the real problem but they seemed to just ignore me. Not one of them would hook up a simple pressure guage. The filter bypass was bypassing the filter and the light figured the oil wasn't getting through the filter i guess. Anyway it's good to post the fixes even if it's an old post because someone might have the same trouble and come accross this post. I know if i would of come accross this post and fix the problem i would kiss the puter screen....but not until i bought it dinner first. LOL
Where did you hook up the pressure gauge to test pressure? what psi gauge did you use?
It's been a year but it was hooked up in the rear by a control valve closer to the rightside of the machine. Im laid off right now but i'll have to go check the book again to be more correct. It was a test port for checking pressure to the clutches. I'll see if i can find it again and get a pic of it for you.
I messed up already....the guage was installed on the left side. The book isn't at the shop. We hired on some kids that never put anything back. The guage was a 1000 psi but i believe the pressure was lower then that...it was a guage i had handy at the time. What trouble are you having?