TC 55DA

   / TC 55DA #11  
Electronic Hydraulic Shuttle Shift. The fwd/rev shuttle function is absolutely controlled by electronics. All the fwd/rev lever controls is an electronic switch that sends a signal to the EHSS controller with controls the fwd/rev servos that control the hydraulic clutch pack. The clutch pedal also has an electronic clutch switch and a cable that attaches to a dump valve spool that moves about 1/10 of an inch to cut flow to the clutch pack. The only problems I had with the electronics on the shuttle controls was that when the wiring would get wet the shuttle wouldn't function. Filling the back side of all of the harness connectors with silicone took care of the problem.

Brian
 
   / TC 55DA #12  
The clutch pedal also has a cable that attaches to a dump valve spool that moves about 1/10 of an inch to cut flow to the clutch pack. Brian

It's not a dump valve. It's a lube oil cutoff valve spool. Big difference.

The system has been made progressively more complex and less reliable since the early 2120's were introduced.
 
   / TC 55DA #13  
I was posting out of ignorance - mine is older and simpler, it looks like.
Jim
 
   / TC 55DA #15  
It's not a dump valve. It's a lube oil cutoff valve spool. Big difference.

The system has been made progressively more complex and less reliable since the early 2120's were introduced.

I figured I had the terminology wrong. It has been awhile since I had the service manual open on one. I was mostly trying to get the point across that the system was very electronically controlled.

Brian
 
   / TC 55DA #16  
Mine's a 1993. I love the shuttle, tho have never owned a hydro, I like that it's not running at high revs all the time.
Jim
 
   / TC 55DA #17  
I was posting out of ignorance - mine is older and simpler, it looks like.
Jim

Not all that much simpler if you have the mode command rocker switch. It's also electronically managed. Early models with 'HSS' on the cowl are the purely mechanical over hydraulic systems.
 
   / TC 55DA
  • Thread Starter
#18  
Mine's a 1993. I love the shuttle, tho have never owned a hydro, I like that it's not running at high revs all the time.
Jim
Mine's the same as well. R3's on mine I see you have R1's. It's been a great machine for the 10 years I've had it. I need something with the same rear axle so my BH subframe will fit.
 

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