Sundstrand hydro adjustment

[Jon925mn 39]

My C-145 hydro has started to think for itself. Got blower on and weights on back but transmission now acting up. She is touchy when engaging lever(jumps some) and wont stay at constant speed as it increases(even on flats). Works fine if you hold it but rather not. I cannot see anything physical with the cam but maybe someone has had same issue and knows a trick or adjustment. Thanks.

[daveoman1966 3,752]

From what you've described...erratic motion control... my bet is that the small tab on the outside of the hoodstand tunnen has broken, letting the motiion control apparatus 'float' at almost randomly.  Look on the left side and see if that tab weld is broken.  It would be the tab on shaft #13 in this schematic.  The other pic is my C-160 auto and the hardware is nearly the same for the Sundstrand units.   

[pfrederi 17,741]

Use 1-1/8 wrench loosen blue nut.  Use 5/8" open end tighten the yellow squared cross shaft.  also check left side of tractor make sure the end of the cross shaft is still securely welded to the tab and bolted in place  yellow mark second pic.

[Jeff-C175 7,202]

Similar (or same) symptoms on my C-125.

 

I found that the "D" hole on the bushing where it fits into the bracket was worn out, presumably because the friction cone was VERY VERY tightly adjusted causing torque to wear the D hole out.

 

 

DO NOT try to weld that bushing to the bracket!  It is an OILITE material that is impregnated with oil and  you will destroy it if you try!  Instead, take it all apart, clean it up real good, and put a dab of JB WELD into the worn "D" area and clamp the bushing while the epoxy sets up.  Then reassemble...  and you don't need a TON of pressure on that spring.  Only enough to provide the tension you need to keep the motion control lever in the position that you place it.   Too tight would contribute to breakage of the welded tab.

 

You can easily observe if this is your problem or not.

 

The bushing and the bracket should move together when you move the motion control handle:

 

 

You should see little to no independent movement between the parts in the circle.  (There will be SOME, but it should be VERY LITTLE!, just a WEE BIT of movement at that point translates to a LOT of movement at the operator end of the motion control stick)

 

And... I know that Dave says not to oil anything on this assembly, I'm not sure why?

 

I feel that you SHOULD oil where the shaft passes through the adjusting screw #6 in the diagram.  Mine was all rusted to 5h1t and very difficult to move.  That may have contributed to the wear of the "D" hole.  If the shaft 'brown welds' itself to the adjuster screw, it would definitely cause a lot of torque and possibly contribute also to the tab weld on the end of the shaft breaking.

 

You don't need to oil the friction parts #11 and #12 since they are the OILITE material.  I don't see where oil there would hurt anything though.

 

 

Edited December 5, 2021 by Jeff-C175

[Jeff R. 35]

Paul

I am not the original poster here, but I wanted to thank you for the detailed information on how to adjust the tension - your instructions are much more detailed than what is found in the owners manual.  My C-160 that I got from my father was very touchy as well and I assumed my father lubricated the mechanism years ago..I adjusted the tension today following your instructions and it is much much better.  I also checked for the broken tab and mine is ok.

 

jeff

[Jon925mn 39]

Small tab is intact on mine. Did notice #3 was not making contact with lever so fixed that. Thanks Dave.

Instructions helpful Paul. Messed with it some and with above things are much more tolerable.

D-hole not worn so far as noticable and bushing is good. Thanks Jeff. 

40 years old its still a solid machine.

[daveoman1966 3,752]

I have two reasons for my comment of "Don't oil anything in here".  (Note the 'in here' part of my comment was not to exclude oil/grease on the hoodstand brass bushings...just the friction components.)   First...This Motion Control apparatus is designed to STAY in the position selected by the operator...based on FRICTION between the components, specifically the CONE and COLLAR. The Cone & Colalr are made of oil-impregnated material, so why add more oil. Oiling of these components, by definition, defeats the FRICTION design. 

Second... Oil is a dirt magnet and THAT is the bane of anything mechanical.  IMHO...stationary parts should remain dry...not oil-soaked.  The Hoodstand Tunnel Cover is to preclude wear from dirt & debris yet oil only attracts that stuff. 

Anyway...this is all IMHO.  Now, it's time for a few cold ones...

  

[Jeff-C175 7,202]

1 minute ago, daveoman1966 said:

stationary parts should remain dry

 

I tend to agree with that Dave, but where the shaft passes through the adjusting screw is not 'stationary', the mechanism rotates on that shaft at that point.  And as I mentioned, the machine I'm currently working on was nearly  'brown welded' in place at that point.  A little bit of oil on that shaft from time to time would have gone a long way to preventing that from rusting up as it did.

 

I'll join you in a cold one as long as it's a Sam Adams Boston Lager!

 

[daveoman1966 3,752]

6 minutes ago, Jeff-C175 said:

 

I tend to agree with that Dave, but where the shaft passes through the adjusting screw is not 'stationary', the mechanism rotates on that shaft at that point.  And as I mentioned, the machine I'm currently working on was nearly  'brown welded' in place at that point.  A little bit of oil on that shaft from time to time would have gone a long way to preventing that from rusting up as it did.

 

I'll join you in a cold one as long as it's a Sam Adams Boston Lager!

 

You buyin'...?

 

[Jeff-C175 7,202]

Just now, daveoman1966 said:

You buyin'...?

 

 

Sure!  First rounds on me!