Shuttle Shift

[Mike058]

How does a shuttle shift control forward/reverse? I thought it was a separate gear box located between the transmission and the differential. Or is it integral with the transmission? And, it's just mechanical, right? I mean, no hydraulics or hydrostatic magic happening.

 

[horse7]

NH can be either clutch-shuttle-(release clutch) [mechanical shuttle shift] or just flick the shuttle level [electro hydraulic shuttle shift, under the covers hydraulic controls for clutching and reversing. Loss of hydraulics means no clutch engagement. There is still a mechanical clutch pedal typically, if one wants to use that but there isn't any need to except for starting].

I imagine all the tractors with shuttles (i.e., non-HS ones that have shuttles) are similar.

Dealer service dept said that electrohydraulic shuttle shift puts less wear on the clutch disks-- I would guess this is especially true for farms that hire people to do work, untrained hired help beats the snot out of mechanical clutches usually (good reason to get HS when possible in those cases).

 

[mojoinco]

On my TN the shuttle shift is clutchless (ok, automagic). But you have to use the clutch if you want to change gears. I don't know if it has a true shuttle box (fwd/rev) or (more than likely) the clutch engages one 'flywheel' or the other for fwds versus reverse. I ought to look it up I guess. The clutchless shuttle shift is an option on this model. A nice compromise with HST.

 

[AndyMA]

On my TN the shuttle shift is clutchless (ok, automagic). But you have to use the clutch if you want to change gears. I don't know if it has a true shuttle box (fwd/rev) or (more than likely) the clutch engages one 'flywheel' or the other for fwds versus reverse. I ought to look it up I guess. The clutchless shuttle shift is an option on this model. A nice compromise with HST.

No contest, in my opinion the electro hydro shuttle ont he TN is just plain better than a hydro. Best of both worlds.

andy

 

[Heywood Jannockitov]

How does a shuttle shift control forward/reverse? I thought it was a separate gear box located between the transmission and the differential. Or is it integral with the transmission? And, it's just mechanical, right? I mean, no hydraulics or hydrostatic magic happening.

On my Case 580 Super E the power shuttle is a separate unit bolted behind the torque converter. It hydraulically actuates the forward/reverse clutches via the steering column lever. the 4 spd transaxle is behind the power shuttle, connected by a short prop shaft. No clutch pedal, and hands down, beats any other setup for ease of use for which it is intended.

I wanted electro-hydraulic power reverser on my new JD 5425 mainly to mimick the operation of the 580 when doing FEL work, but didn't want HST.

The beauty of any shuttle, whether it is non-synchro, synchro or hydraulic is that by separating the F-N-R lever from the gear selector lever is you leave the tranny in the gear you need and just move the shuttle back and forth to change direction.

Do a lot of back and forth FEL work with a conventional non-shuttle gear transmission where you're hunting for reverse in the H pattern and it gets tedious pretty fast.

My IH454 has a separate non-synchro shuttle lever. Non-synchro means coming to a complete stop before shifting the shuttle lever. All the linkage goes to the same spot in the tranny, so it appears to be integral.
Also, synchro-shuttle = single plate dry clutch.
Power shuttle = multi plate wet clutch = greater durability.

 

[RWolf]

My JD5103 has the shuttle shift as I only plan on doing FEL work on occasion. It's integrated with the tranny and has a separate range shift. The pattern is a modified H. What they did was exchanged 1st and 2nd so when shifting your got 2-N-R. Works like a dream. I still have to use the clutch but that's a no-brainer for me as I like a manual shift.