1490 hydraulic pump shaft and couplers

Posted by pringles on 2009-09-18 14:04:00 

Hi all,

My 1490 needs a new hydraulic pump shaft, coupler at the crankshaft and coupler at the pump.

For some reason my high platform 1490 has the air conditioner compressor pulley option so I have the shorter hydraulic drive shaft K201216 instead of the more common K944950. The compressor pulley just simply couples into the crankshaft pulley and the hydraulic shaft coupler couples into the compressor pulley. I would like to get rid of my compressor pulley and just connect the crankshaft hydraulic coupler right into the crankshaft pulley (alternator belt pulley). To do this I need to use the shorter smaller rubber bumper that goes between the end of the hydraulic shaft and the crankshaft end. The problem is that I don't know which one to use. The Case parts site gives a choice as follows.

Section K02-1 item #35 K627581 7/16" Thick
K627582 9/16" Thick
K627583 5/8" Thick

Not much of a difference for a part that seems not to refined in it's purpose of fitment.

Can anyone shed some light on why there are three parts to choose from and why the difference between them (very small difference)

Thanks,
Steve.
Posted by: john1694 on 2009-09-18 17:00:00 
As much as anything the differences were to accommodate slightly different clearances between major "fixed" components on different tractors/models...but in this situation and at level it's a bit anal  The difference between the shaft end on the aircon model and non-aircon model will be slightly different as well. Are you retaining the second pulley? I removed both mine ( and the aircon system from the 1694 too ) as one demolished the crank end through too much side pull.
The rubber allows expansion of the components without them getting tight, and stops rattling of the shaft - which the orings do anyway. Absence of the rubber will allow the shaft to decouple and ruin the cups/ends. I only ever ordered one size - and I can't remember which it was - but probably the only stocked locally which would be the middle size. You can always shave a little off if you think it's too tight!
Posted by: pringles on 2009-09-18 18:30:00 
What is the difference in the shaft end? Which end of the shaft is different, the crankshaft end or the hydraulic pump coupler end. I think the number of teeth is the same and the fitment of that since there is only one part number listed for the crankshaft coupler and the hydraulic pump coupler.

I am not sure what you mean by the second pulley. I only have one, the air conditioner compressor pulley. Not including the crankshaft pulley since it has to stay of course. I am removing it so I can use the more standard longer hydraulic drive shaft. The only place I can get the short 8" drive shaft used on the air conditioned models is Case and they want $300.00. Take a hike Case!

Is the correct fitment of the rubber spacer such that they would be no end play on the shaft. That is, the shaft butts against the rubber spacer which in turn bumps against the crankshaft. Or, is there suppose to be some play, 1/16" or something small. I realize that it's purpose is to keep the teeth engaged but I am not sure what the correct fit should be, tight with no play or not.

thanks for your help.