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Dan, Technician
Category: Construction and Road Equipment
Satisfied Customers: 5300
Experience:  17+ yrs. shop and field experience with all major brands of heavy equipment and trucks - 1995 WyoTech graduate.
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I have a John Deere 450C dozer. 1976 model. Dozer was fine

Customer Question

I have a John Deere 450C dozer. 1976 model. Dozer was fine when parked in April. This morning it fails to engage transmission. runs fine. hydraulics for blade are operating. I have tried different gears and shuttle shift in different positions.
Submitted: 2 years ago.
Category: Construction and Road Equipment
Expert:  Dan replied 2 years ago.
Hi my name is***** will be glad to help. These transmissions are known for problems. Check the oil for metal/debris indicating an internal problem and if clean verify your clutch adjustment specs clutch pressures , rate of shift.etc. Look for discoloration or burnt smell of the oil indicating internal issues as well. Let me know
Customer: replied 2 years ago.
Dan, thanks for your response. Does it make sense to you that the dozer was fine until parked 3-4 months ago then wouldn't engage the trans at all now? you can change gears at will with the motor running and the clutch out. no grinding at all. the best way i can describe it is - you can shift the same whether the clutch is engaged or not.
Expert:  Dan replied 2 years ago.
What is your machine serial number??
Customer: replied 2 years ago.
gosh. where would I find that? The dozer actually belongs to my Dad (who is 84) and I'm not really a very good mechanic By the way - I don't mean to sound like I'm a kid. I'm 62.
Expert:  Dan replied 2 years ago.
It should be on the metal tag on the front of the console next to the seat. There are a couple possibilities. Either a loss of pressure from a faulty pump or other internal transmission problems if the linkage is good or a faulty clutch. Under the floor there is a plug below your feet you can install and adaptt a 500PSI gauge using a grease gun whip hose. The steel ones work best as it is 1/8" pipe. You adapt your gauge with fittings to this and then you can see if you have clutch pressure
Expert:  Dan replied 2 years ago.
I can look up those specs for you when I get back in the office
Expert:  Dan replied 2 years ago.
Will the machine not travel at all or will it try to move one track in any direction? Here is a link to help with some added info. A common issue is the clutch manifold bypassing pressure but this requires engine removal and dis-assembly of the transmission. I recommend checking the transmission stainer and filter for signs of metal indicating an internal problem. Let me know
Customer: replied 2 years ago.
serial #229699T. Machine will not travel at all. Transmission appears to be in neutral no matter what I do. No bumps, jerks, or any indication it has been put into gear. Blade operates normally, up, down or tilt all are normal.
Expert:  Dan replied 2 years ago.
Thanks for the info. The hydraulics are run off the pump driven off the front of the engine crankshaft pulley. The transmission has a separate pump internally at the input shaft of the transmission. I would see what you have for transmission pressures.

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