eepete
Platinum Member
I recently had the "enhanced" or "automotive type" cruise control added to my 2009 Deere 4520 when it was in the shop for a few "minor" repairs. The cruise control works great, and the ability to incrementally change the speed by pushing a switch is great :thumbsup:.
When mowing with my MX6, I tend to be in the B range with load match on and auto throttle off. In fact, in general, I only use auto throttle when driving around the place. Seemed like a nice way to vary the engine speed and help with the break-in process. Most of the time, I don't want to mow faster than 4-5 MPH. The cruise control has the "max speed" setting where you can bring the tractor to the desired max speed, throw the cruise control switch to max speed, hit the "set" button, and then release the foot control. Then (in theory) no matter how far you depress the foot peddle the max speed the tractor will move will be what you set it to. That max speed can also be incrementally adjusted using the + and - button while you have the peddle fully depressed.
The max speed function doesn't work very well. If you're going up a hill, it slows way down, if you're going down a hill, it speeds up. So today I did a test. I have a section of my driveway where it is level, then goes downhill a bit, then goes uphill. I first went up the hill with the autothrottle at 5.5 MPH and noted the RPM. For the test, I was 200 RPM above that point. I had no implements on the tractor, PTO off, load match off, auto-throttle off.
With cruise control on and setting the speed to 4.7 MPH, for both the downhill and uphill sections the speed stayed within +- .2 MPH (i.e. 4.5 to 4.9 MPH) and most of the time was within .1 MPH. I then went back and tried the same course with the max speed function, setting a speed of 4 MPH as the max speed. So I was going on a level surface with the pedal all the way down doing 4 MPH with max speed cruise control enabled. When going down the hill, the speed went up to 5.6 MPH. When going up the hill, the speed went down to 2.6 MPH. I went back again and when going up the hill I turned off the max speed function and _quickly_ went to over 6 MPH , so this is not a power issue.
So my question is: Is anyone else seeing this with the max speed function :confused3: ? Clearly the control system can maintain and regulate the speed fairly precisely, and this is not a case of being underpowered on the hill. The max function just doesn't seem to work well.
Sorry the details were not as short as the question My next step is to tear into the service manual. I've talked to my Deere Dealer and will give him this same information.
Pete
When mowing with my MX6, I tend to be in the B range with load match on and auto throttle off. In fact, in general, I only use auto throttle when driving around the place. Seemed like a nice way to vary the engine speed and help with the break-in process. Most of the time, I don't want to mow faster than 4-5 MPH. The cruise control has the "max speed" setting where you can bring the tractor to the desired max speed, throw the cruise control switch to max speed, hit the "set" button, and then release the foot control. Then (in theory) no matter how far you depress the foot peddle the max speed the tractor will move will be what you set it to. That max speed can also be incrementally adjusted using the + and - button while you have the peddle fully depressed.
The max speed function doesn't work very well. If you're going up a hill, it slows way down, if you're going down a hill, it speeds up. So today I did a test. I have a section of my driveway where it is level, then goes downhill a bit, then goes uphill. I first went up the hill with the autothrottle at 5.5 MPH and noted the RPM. For the test, I was 200 RPM above that point. I had no implements on the tractor, PTO off, load match off, auto-throttle off.
With cruise control on and setting the speed to 4.7 MPH, for both the downhill and uphill sections the speed stayed within +- .2 MPH (i.e. 4.5 to 4.9 MPH) and most of the time was within .1 MPH. I then went back and tried the same course with the max speed function, setting a speed of 4 MPH as the max speed. So I was going on a level surface with the pedal all the way down doing 4 MPH with max speed cruise control enabled. When going down the hill, the speed went up to 5.6 MPH. When going up the hill, the speed went down to 2.6 MPH. I went back again and when going up the hill I turned off the max speed function and _quickly_ went to over 6 MPH , so this is not a power issue.
So my question is: Is anyone else seeing this with the max speed function :confused3: ? Clearly the control system can maintain and regulate the speed fairly precisely, and this is not a case of being underpowered on the hill. The max function just doesn't seem to work well.
Sorry the details were not as short as the question My next step is to tear into the service manual. I've talked to my Deere Dealer and will give him this same information.
Pete