185 woes for the Doctor and others

We. Have discovered an issue with our new to us 185 while baling and while on hills and while slipping the hi lo feeding heavy windrows. First off going uphill under load baling or even just going uphill not baling just pulling there is a distinct loud chirping noise in the final drive axle or transmission . If we turn to the right under load it gets way worse and is scarey like really loud binding noises . While starting the tractor every time the pto will immediately fly up out of off to partway on, enough to run a baler if one would let out the clutch at that moment. This occurs on every start up. Also in heavy windrows while slipping the power director in low she will grab occasionally and will not release even after putting it in neutral and even after putting it into high range and back to neutral. This issue can only be terminated by foot clutching. While tractor is sitting idling if we lock pto off there is no chirping noise in the torque tube tranny area. If we position pto lever out of off the noise continues to chirp. While pulling the double rakes or Tedder or haybines there's no chirping or binding noises however the pto somehow always comes out of the off detent and is partially engaged. In summary ,a dead pull going uphill with or without pto engaged and turning right will makemasevere binding noise like snapping metal. We can live with the pto popping on issues but are afraid of the uphill turning right under load issues. This concern is for both mechanical and possibles loss of life on our hills. Help please! Dana

Hi and thank you for the reply Doc. I have the original Allis 180 and 185 Tractor Service Manual. I do not see info on checking the pressure reg spool in the pd. It sure could be in there but any more info on how to do this check will be greatly appreciated. As far as the noises and the brakes are concerned it is not the brakes I kmow all about those issues and although I have not replaced these brakes in this tractor I have in many others and can rule that out. I did go out and dead pull the XT hooked to the NH315 up my bad hills and it performed flawlessly. Of course the PTO was not under load while doing so. let me know how to check that press reg spool thanks sooo muchn. Dana and Ian

Ok wow holy moley thank you for all of your incredible knowledge I will report as I find out more answers. I am wondering do I plumb the gauge into the pd line and run it and report the pressures I see? Approximately what pressure should it be? At what engine rpm? Sorry for my uncertainty but I can find nothing in my service manual on this. Thank you.

Pressure ports on the manifold under the right platform...1/4" pipe thread.  Pressures should be under 300 psi at half throttle or more.

I also removed both 7/8 plugs under pto valve. Both had some metal filings in the plug cavity. Theres absolutely no leakage of oil anywhere around these valves.

Also we plumbed gauge into both ports on pto valve. Pressures stay at 270 at all engine rpm settings while engaging and disengaging pto with the 10 psi flicker. The problem we see is at lower Rpm pulling pd from hi to low range will spike pressure to 350 and kick pto on if it's off. However with rpms over half throttle or more pulling hi to low on pd only shows the 10 psi flicker.

The 260 psi sounds about right for each range of the P.D. clutch.  I'd expect near zero on the range that is not applied.  Clearly the 350 psi spike is causing your PTO lever detent to let go.  Is the detent worn or weak??  Is that pressure spike normal or not??  I'd have to compare to another tractor to answer that.  One 7/8" plug is for the low/neutral/high spool. The other one is for the pressure regulator spool. Should be a spring, some shims, a spool and a floating slug in the end of the spool. Did you remove all of this?? and is everything free??  Like I say that not zero number on the PD clutch bothers me.

Ok y'all thanks for everything. I did not like that 350 psi spike so I took that regulator apart again, this time i dug with a fine little screwdriver under the spring and low and behold there was a 1/4 inch nut used for a shim. Since the pressures were nearly right on except for the spike to 350, I threw out that nut and put in 2 washer shims so now I have 270 psi pressures and when i pull back from hi to lo it spikes to just under 300 so my pto lever wiggles but does not fly out of off. I do not know if this is acceptable or not. Since my pto valve only spikes 10 psi while engaguing and disengauging and neutral to high on pd spikes 10 psi also but when I pull pd back to low it spikes more than the others maybe there is something amiss inside the low range valve.jThanks, Dana

Yes Doc the detents are solid and since I lowered the pressures it does not pop the pto out of off anymore. Id like to see inside of that pd how that works some day!