1966 jd 450 won't move

[farm4$]

i am looking for some help on this 450 (early) crawler loader please; this was my uncles machine; my cousin was operating it and everything ok; they stopped for a break and when they returned to work the machine wouldn't move; that was 6 yrs ago; i have purchased the machine and have done engine work, and cleaned the tranny filter screen (it was a mess) and changed the front filter at the rad cooler. filled it with new oil and it still won't move. i'm postitive the engine clutch is fine cuz the trans pump stops when disengaged. i put a pressure guage under the seat and the pressure will come up but takes awhile . the pressure will go to 165 psi.when u put it in gear at that pressure,still doesn't move. i personally think there is a blockage because the filter was bad . i am wondering if i could put air pressure to it somewhere to try to backfeed pressure and maybe move something; looking for some advice it i can get it; thanx

[Jim B]

Welcome to the Boards.

You need to go through all the checks in the Service Manual SM2064 to try to pinpoint the issue. It does sound like a plug or major leak somewhere stopping oil from getting to the clutches if it doesn't move in either direction. It would seem like a leak would show a pressure drop, so plug seems more likely. Another thought would be a disconnected linkage.

Are you using John Deere Hy Gard or a UTHF meeting the J20C spec? do not use plain hydraulic oil or a fluid claiming to be 303.

A bit of housekeeping on the boards. This Early Models Board is for the 1010s, 2010s and the models before them. Your posts about your 450 should be on the Late Models Board, which is for the 350s, 450s and the models following them to current. This Early Models Board is for the 2010 series and before. It is likely a Moderator will move this thread to the Late Models Board when they see it.

[farm4$]

thanks for info; i have a guage under the seat and it produces at least 160 psi; but when u first start the machine it takes a while before it will climb;; i have done the foot clutch linkage and the adustment for the valve; 4 turn thing; when this machine is up to pressure, there isn't a hint of engagement on the high low reverse selector gear, although when u go from reverse to forward the drop in pressure seems to be proper .; when u put the hlr lever in neutral, the pressure drops as it should but when u reengage it takes maybe a minute or so to recover the pressure; i used tdh fluid when i refilled it cuz it will have to be changed soon anyway cuz there was water in the tranny; thanx for your input, it is greatly appreciated. do u think heavier oil would solve the problem?

[Jim B]

You need a fluid/oil meeting the J20C spec in the HLR Transmission for the wet clutches, or they can be destroyed. If you are using Chevron TDH it should say in the specs if it meets John Deere J20C. I would not use a fluid that does not meet J20C.

To go from working with no problems to not moving after being shut off for lunch, sounds like something has unhooked or there was a major internal failure.

[farm4$]

ok thanks jim; i think i will just move forward and remove the top; i'm hoping to see some linkage off; i think there is a flow divider in the clutch valve; may be stuck; i just checked it again and the pump is putting out 170 psi. i have noticed when i rev the engine higher the oil will come to the top of the opening where the guage is, so maybe cracked line ???

[farm4$]

to finish the last post; the gears wouldn't be turning to bring oil up?

[farm4$]

i have the top off t he trans on this 450 now and there seems to be rust of the accumulator body; the parts book shows a screen in that casting; i was also wondering what controls the clutch valve; is it the rod that comes from the front dry clutch; i started the machine up and the pump is certainly pumping lots of oil on the hydraulic clutches which look very good; doesn't seem to be any linkage problems unless the clutch spool that is below the shifter spool is stuck; :my next move is to remove the accumulator body;