1972 Ford 3400 - Front Hyd Pump Shaft Stripped... where do I start ?

wardens33 · Apr 19, 2014

Is there anybody out there that can give a rookie some tips on where to start to repair what appears to be a stripped front hydraulic pump shaft. Was using my 72 Ford 3400 the other day and it was making a bit of a chirping noise almost like a water pump bearing. When I fired it up today, I raised the bucket a few inches and then nothing but a rattling noise from the front. Upon further inspection it appears that the shaft wich drives the front mounted hydraulic pump has stripped where it plugs into the crank pulley. I can grab the coupler and run it freely. The pump shaft turns ok as does the shaft, but it just spins freely where it plugs into the lower pulley on the front of the engine.

My first question is, Does the whole front end loader have to be removed to pull the shaft out and inspect whats wrong ? I am hoping its the shaft and not the Inner spline on the engine pulley.

I also notice a post from sd455dan where he had trouble with his but no leads on how to get that shaft out of there.

Any tips would be appreciated.

RickB · Apr 19, 2014

Drain the oil, remove the pump. Shaft is trapped between the pump & coupler flange bolted to the crankshaft. Take tractor and loader model numbers to your NH dealer (or call) and give the length , diameter, and spline count of the shaft (and any couplers) you need. There are a bunch of different components, but most, if not all are still available. The ones you need are all but certain to be available from New Holland and probably TISCO as well.

Harvey H · Apr 20, 2014

Unbolt the pump and pull it straight out the front. Most of the time there is enough slack in the hoses that you do not need to break the lines. The shaft will then pull out to the point you can see what the worn item is. There are four bolts that hold the drive spline to the crankshaft pulley. Access from underneath or remove whatever necessary to access it if it is damaged. Parts are available as aftermarket. I think this is the front coupler you are looking for: Aftermarket Replacement Parts For Tractors & Combines | C5NNN879A - $52.06, Hub, Hydraulic Pump For Ford / New Holland INDUSTR there are some shafts listed in the description as Ford used different lengths depending on the need.
Also here is a part number for the shaft to pump coupler just in case thats the problem: A-7707570