Grand L 40s - HST Plus

[TalonDancer]

OK, I think I get it. It sounds like the Cruise control ONLY works the HST control and NOT the throttle advance. With Auto Throttle Advance engaged, the HST setting is the greater of the Peddle or the Cruise Control lever, and the throttle setting depends ONLY on the peddle position. This is understandable behavior, but doesn't seem very useful. I'd guess the Cruise control is not intended for use with the Throttle Advance.

Well for the last 125+ hrs I've had the Auto Throttle ON 99% of the time and used the "Cruise Control" lever almost every time I'm going forward for any distance on relatively level ground Because it reduces the RPM (read engine noise) required to achive/hold a given speed and keeps the engine in it's highest torque range.

As I've posted before, the Cruise Control lever is simply misnamed on HST Plus tractors. It should be called the Manual HST Control (similar to the Manual Throttle Control) Because what it actually does is manually control the HST "gear".

When used in conjunction with a manual throttle control it approximates cruise control in autos, etc. (hence the marketing name/lable "Cruise Control"). But when used with the Auto Throttle feature it advances the HST without increasing the engine revs. more closely approximating "overdrive" in an auto, truck, etc..

BTW the description of the Cruise Control feature is missing from the Grand L 40 section of Kubota's current web site and somehow was left out of the 6 pages of HST Plus description in the Grand L 40 sales brochure. Maybe it was just too complicated to explain to new buyers

Talon Dancer

 

[beppington]

This thread has my head spinning. I guess I need to go drive Kubota's HST for this all to make sense.

 

[beppington]

9- Cruise Control - which AFAIK only vaguely resembles cruise control in cars.
a- it does shut off when you press the brake.
b- it will keep the tractor moving forward when you take you foot of the HST pedal. But even when set to full on, the forward motion is pretty slow.

Is this still the case on yours? Mine's top speed is actually just a hair faster with the Cruise Control bar at maximum vs the hydro pedal to the floor.

 

[texasjohn]

On my tractor there is a bolt sticking out of the floorboard that is used as a stop for the HST pedal rocker when going forward. It is adjustable. Perhaps yours could be adjusted to achieve more forward speed, if this is something you need.

 

[TalonDancer]

Is this still the case on yours? Mine's top speed is actually just a hair faster with the Cruise Control bar at maximum vs the hydro pedal to the floor.

Yes. But remember that I was describing the use of the Cruise Control bar in conjunction with Auto Throttle. In this case when the engine is idling, the Cruise Control bar simply works like a manual HST lever.

IOW you can get the same result two ways. With the hand throttle set to idle and....
1 - with Auto Throttle ON (and your foot off the HST pedal) push the Cruise Control lever forward or
2 - with Auto Throttle OFF push the HST pedal down

Talon Dancer

 

[beppington]

I'm not near my tractor right now to check - Are you saying that with Auto Throttle on & the hand throttle set at idle, as I ease the Cruise Control bar forward the RPM will increase? If so, that'd be cool!

I have to drive mine ~4 miles to my property each time, & it's a little bothersome (not terrible, but...) to have to manually reduce throttle at stops signs. I know I don't really have to, but it seems silly to sit there at a stop sign with the engine close to max throttle, waiting until I can go.

(I really haven't fiddled with the HST Plus much as I've been able to easily/ quickly accomplish what I've needed to do (almost all bush hogging so far) without using Stall Guard or Auto H-DS (very little FEL work so far); Didn't think I needed Auto Throttle, either, but maybe I do!)

 

[TalonDancer]

I'm not near my tractor right now to check - Are you saying that with Auto Throttle on & the hand throttle set at idle, as I ease the Cruise Control bar forward the RPM will increase? If so, that'd be cool!

I have to drive mine ~4 miles to my property each time, & it's a little bothersome (not terrible, but...) to have to manually reduce throttle at stops signs. I know I don't really have to, but it seems silly to sit there at a stop sign with the engine close to max throttle, waiting until I can go.

(I really haven't fiddled with the HST Plus much as I've been able to easily/ quickly accomplish what I've needed to do (almost all bush hogging so far) without using Stall Guard or Auto H-DS (very little FEL work so far); Didn't think I needed Auto Throttle, either, but maybe I do!)

No. "with Auto Throttle on & the hand throttle set at idle, as I ease the Cruise Control bar forward" it will be just like you pressed down on the HST pedal WITHOUT increasing the engine RPM. IOW it will slowly start moving the tractor. But it won;t go very fast.

The Auto Throttle converts the HST pedal into an HST pedal AND a throttle pedal. If you get it adjusted properly, it is just like driving a car. The HST pedal becomes the 'gas pedal'. BUT... in order to use the Cruise Control to hold a steady speed you have to turn Auto Throttle OFF and use the hand throttle.

Note I use Auto Throttle nearly 100% of the time, because in 3yrs (600hrs) my L3240 has been exclusively used for FEL, Fork Lift, Back Hoe and Box blading. IOW I have never used the PTO.

Talon Dancer

 

[lawn_king]

I love the hst + tranny!!! I use hi-lo constantly as well as stall guard. I perfer hst responce on slow for most applications with the exception of loader work. I only use auto throttle for snow operations, where it saves a ton of time loading & moving snow. I set the cruise control & use the digital ground speed indicator to accurately apply granular and liquid lawn care products. Hst + is a great advance over the standard kubota hydro!

 

[beppington]

No. "with Auto Throttle on & the hand throttle set at idle, as I ease the Cruise Control bar forward" it will be just like you pressed down on the HST pedal WITHOUT increasing the engine RPM. IOW it will slowly start moving the tractor. But it won;t go very fast.

The Auto Throttle converts the HST pedal into an HST pedal AND a throttle pedal. If you get it adjusted properly, it is just like driving a car. The HST pedal becomes the 'gas pedal'. BUT... in order to use the Cruise Control to hold a steady speed you have to turn Auto Throttle OFF and use the hand throttle.

Since posting earlier I visited mine & discovered just that.

Note I use Auto Throttle nearly 100% of the time, because in 3yrs (600hrs) my L3240 has been exclusively used for FEL, Fork Lift, Back Hoe and Box blading. IOW I have never used the PTO.

We use our tractors almost exactly opposite of each other then - My PTO is on almost all the time! :thumbsup:

 

[TalonDancer]

....We use our tractors almost exactly opposite of each other then - My PTO is on almost all the time! :thumbsup:

Exactly! The key is how the tractor is being used. The beauty of the HST+ is that it allows you to...

Turn the Auto Throttle ON when a tractor is used as a TLB. This is particularly handy for loader work and positioning the back hoe etc. where having the engine RPM linked to the HST pedal nearly always 'makes sense'. IOW in this configuration, nearly all of the engine's "load" is linked to moving the tractor.

Turn the Auto Throttle OFF when the tractor is used with PTO (mid or rear) implements. When using the PTO the load is somewhat independent of moving the tractor. IOW in this configuration, a high percentage of the engine's "load" goes to running the PTO implement.

But.... You can just leave Auto Throttle ON all the time, because the Hand Throttle overrides the throttle linkage to the HST pedal. So if you have a PTO implement engaged, just set your engine speed with the hand throttle and use the HST pedal to control ground speed. But when you are traveling with out the the PTO implement engaged, pull back of the hand throttle and use the HST pedal for both engine speed and ground speed.

Talon Dancer