J.D. 4450 p quad-range

[James A.]

mattd. Hi, did these pressure checks at engine idle 1000 rpm's. I checked Hyd.scv. sits about 2200 psi. only has 25 hrs. on new oil&filters. Hi/Lo linkage is good.with all the info you have given me. I must be low on pressure at the Hi/Lo valve? Thank you so much for all the information because I am not framiliar with this tractor. Thanks again.

 

[mattd]

well i wouldnt add shims if you had that much psi at 1000 rpm. but if it doesnt gain much at 2000 then maybe add 1. the hi/lo valve unfortunately is located on the hi/lo clutch housing so it needs split to get to it. if the shifts are hesitant both ways then it might have some grooves in it or is sticking

 

[Bob]

The quad-range 2-speed is shifted by relatively low pressure oil from the transmission pump (in the 180-200 PSI range), which also is the operating pressure of the Perma Clutch.

The 2250 PSI output of the main hydraulic pump has NOTHING to do with the shifting of the Quad-Range 2-speed.

(IF that is what you are asking.)

The oil from the transmission pump, after supplying the needs of the 2-speed, Perma Clutch, and PTO clutch goes on to "charge" the main hydraulic pump.