JD300B

[otis01]

Hello everyone. I am new member who could use some advice. I have a 1972 JD 300b backhoe diesel that has a starting issue. When it sits for a day or so it starts right up after running it if I shut it down it barely turns over and will not turn fast enough to start. Battery voltage checks out. It seems like hydraulic system is putting a drag on the engine. All selective valves are in neutral position. Has anyone ever had symptoms similar to this on their machine? Any help would be greatly appreciated. Thanks

 

[hosspuller]

Had the same issue. Get an ammeter, and check the current draw of the starter. Voltage doesn't tell much about the system unless under load. My starter was dragging internally. The bushings had worn and the armature was contacting the field coils.

 

[Tx Jim]

Has battery ground cable been relocated from battery box connection to engine block/starter mounting bolt?? If your TLB doesn't have a hyd destroking screw(parts key 6) you can install and use it to put hyd pump out of stroke while cranking engine.JD also offers an electric destroker kit. These parts listed fit the larger pump & if your TLB has the smaller pump it requires different parts.
parts key 6-AR96625 Pump Repair Kit - FIELD INSTALLATION KIT, SCREW, HYD ADD 16.88 USD
RE40463 Hydraulic Pump - HYDRAULIC PUMP, HYDRAULIC PUMP ELEC ADD 617.77 USD

 

[otis01]

Had the same issue. Get an ammeter, and check the current draw of the starter. Voltage doesn't tell much about the system unless under load. My starter was dragging internally. The bushings had worn and the armature was contacting the field coils.

Thanks I'll check it. May not get to it for couple of days.

 

[otis01]

Battery cables are new ground is still connected in battery box. Would you recommend moving it to block/starter? 55

 

[jd110]

Another "trick" you can try is to jerk steering wheel back and forth while cranking the engine. This doesn't fix anything, but it does help with getting it started when starting system is weak. It is possible you also have internal high pressure hydraulic leaks that are keeping hydraulic pump in stroke when you are trying to start. If you start tractor and leave it sit and run for 20 minutes or so, try feeling different hydraulic components for heat. Steering valve and three point hitch housing on front right side of housing are typical leak areas.

 

[Tx Jim]

Battery cables are new ground is still connected in battery box. Would you recommend moving it to block/starter? 55

YES relocating battery ground cable to engine should help hard starting problem

 

[otis01]

Amperage draw through the roof. Had starter rebuilt. Up and running great. Thanks for the help.

 

[otis01]

Moved cable to starter bolt. Thanks