D200 hydro control sticky

[giantsean 59]

Hi.  I was using my repowered D today and all was going well... until the motion control arm became sticky and hard to move back and forth.  At first I thought some cables and wiring got jammed up in the linkage (and there still might be something happening in there) but it looks free enough, so I suspect it may be something internal.  Technically it still works, and otherwise no weird noises, smells, or leaks, but I don't want to push it.  Is this a common occurrence with older hydro pumps?  I will say I thought it was leaking but realized it was a little bit of water from the battery that spilled over.  Am hoping it didn't drip in a perfect spot and get something gummed up.

 

Thx for any info!

[giantsean 59]

Should clarify too.. when I say "sticky" I actually mean it takes a considerable amount of force to push it back and forth, vs it being able to almost move by itself from normal vibrations (not saying that is good either lol).  Wondering if it may be a trunion shaft bearing or something, which would really stink.

[pfrederi 17,885]

D series motion control linkages are complex and can be frustrating to get adjusted correctly. Try the friction adjustment shown in the picture .  You can download the manual  here.

 

 

 

Edited May 10, 2019 by pfrederi

[giantsean 59]

Thanks... I actually found the Sunstrand manual last night and that's exactly where I was heading when I started tearing into it, exactly right when it started raining lol.   Leave it to WH to make an access plate upon which things bolt to and provide structure too... because why not?  So anyway, I took apart the vestigial brake mechanism and rod (just hanging there) and tossed it in the pile as it does zilch at the moment, took the jam nuts out and found a spacer upon which the bracket pivots had fallen out and was jamming up between the plate and the stud.  Trunion shaft nice and free... I think the entire neighborhood heard the sigh of relief :P.  I have been grading dirt and knocking it around a bit, so it may have just come loose at some point.  Got the mechanism back together and ditched the whole shebang until it stops raining.

 

This is not the first time I've had to deal w/ the suspect engineering of the D-series motion control system.  This frame in an earlier life was a 73 or 74 w/ the parking brake mechanism built into the motion control.  The pivot point for the arm simply friction fits to the plate that moves all these rods and levers.  When it comes loose, it just falls off and no more motion control.  Unless you are already moving, and in that case, no more stopping lol.  This happened to me exactly once and I was able to shut it down before it drove the the back of my garage.  I luckily had a newer style spare which did the trick.  Still I wonder what those engineers were smoking when they designed that.

 

I also learned while in there that my hydro pump appears to be simply held in by gravity alone lol.  I doubt that's actually true or it would be spinning all about, but there are several mounting holes w/o bolts.  As it's a repower the PO may have had alignment problems and this was the only way to make it work, but something I'll have to look into later.  I'll post pics later on another thread to get some ideas.