Hey, to anyone that can help me with this. Dose anyone else have issue where the 988k goin downnhil, keeps dropping down gears and over reving it's self. Has the hydro static transmission and can't seem to keep a consistent speed to the bottom. Any tips on how to keep a constant speed?
No it doesn't. It has a 4-speed powershift transmission. Question: What gear are you using to descend grades and if you need to control the machine ground speed which brake pedal do you use.? Is there still an Operation Manual in the pocket behind the seat.?
The loader has a switched Reluctance Electric Drive. Not a standard hydrostatic transmission but close enough. In this loader you can select gears 1-4. But you can also select gearing in increments. So 1.4-1.6 and so on. Your thinking of a standard transmission where you have to gear down as you go into a pile. This loader you don't, it works of variable speed, and as you slow down the torque increases. Right now there is mixed reviews as we have 2 bran new 988 EX loaders that don't have this issue. But the 988k XE seems to Wanna grab and hold you back using the service break more then is needed. I have total control of the machine and using the left pedal to control decent. But no matter what it seems to wanna keep pulling back to a almost stop. Messing around and talking to guys that run these things regularly, they seem to be goin down with the transmission in 4th gear. I tend to think that's way to aggressive and go for a more 3rd gear. Tried with throttle lock on and off, goin down with no left pedal action and pedal 3/4 down. Alwasy the same, loader will keep slowing down on its own and even over reving no matter how much or little the left pedal is pushed. Yes i have read the book back to front, trying to find a setting or something that could be causing this issue. But no book can replace asking questions of ppl that have experience on running this machine and might have a tip or a way they go down hills without having this issue.
As a general rule of thumb any grade should be descended using the same gear as the loader will require to comfortably climb it. So if it climbs in 3rd speed then use 3rd speed for descending. Do you have a Serial Number.? Just to make sure I'm on the same page as regards how the machine is configured. Does your cab pedal layout look somewhat like this.? It's allegedly from an 988K XE.
Well the loader climbs the hill with a full bucket at 9-10kms, witch would be about second for speed. I'll definitely have to try that, and see if it makes a difference. I don't have the serial number as I didn't think I'd be asking on a forum about this lol. Here's a picture of the manual I got from the one loader.
Is it also descending with a full bucket or empty.? If a full bucket then 2nd gear would be appropriate, if empty the try climbing the same ramp empty and see in which gear it is happiest. Don’t need a S/N with that photo. I had already figured out it was either an E8X or EWX model. I just needed to confirm it. So can you confirm that you have the three pedals as shown in both your illustration and mine.? And if that is the case do you understand the differences between how the left and right brake pedals operate, particularly when it comes to their effect on the machine powertrain.?
Empty bucket downhill, has the three pedals. The left pedal is a rim pull with breaks on the last little bit. The one next to the accelerator is a dedicated brake. You pretty much use the left brake with machine with throttle lock on. Works the best for feeding/traming material.
That is exactly how it works. It's a powershift version of feathering the clutch on a manual transmission but with the added bonus that the same pedal can also apply the brake if you push it a bit further. OK, so you will have to do some testing with an empty bucket working uphill to find out what is the most suitable transmission speed. I suspect it might be 3rd speed but you will need to confirm that with a physical test. It may even be 2nd speed. Let me go back and quote one of your earlier posts. Note the part that is underlined and relate it to my comparison of the left pedal with the clutch on a manual transmission. The first few degrees of travel of the left pedal will disengage the impeller clutch in the torque converter and as a result take away any engine braking effect that would normally help to control ground speed during the descent of a grade. I have come across this a number of times before. Here are my suggestions:- 1. As already discussed, identify the correct transmission speed for descending a particular ramp. Note that it may change from one ramp to another depending on the actual grade. It may also change depending on ground conditions, e.g. wet vs dry, etc. 2. Slow down and engage the appropriate transmission speed at the top of the ramp before the machine transitions on to the downgrade. 3. Allow the engine braking to control machine speed for the most part. If the ground speed or engine RPM becomes too high for comfort use the RIGHT brake pedal as necessary to reduce the machine speed. EDIT: 4. Don't use the Throttle Lock. After I wrote all the above from memory I looked at the O&M Manual. The quote below comes from the Manual M00700448. Downhill Operation Before you start down a hill or grade, select the appropriate gear to maintain a proper ground speed. Select a speed that is slow enough for the grade and conditions. In most situations, the proper gear will be the same gear that is required to drive up the grade. The proper gear should allow the machine to maintain the appropriate speed without continuous use of the brakes. If necessary use the right service brake pedal in order to slow the machine. The engine speed should be in the mid range or higher to maintain proper cooling and lubrication of the machine systems. Using either service brake pedal continuously to control travel speed of the machine on a grade can cause the brake discs and axle oil to overheat. This use of the service brake can result in significant wear and /or damage to the service brakes and final drives. Note: The left impeller clutch/brake pedal should not be used for downhill braking. Using the left impeller clutch/brake pedal will disengage the engine from the power train. This action will increase the load on the service brakes, increasing the risk of significant wear and/or damage to the service brakes and final drive
I have another question. Are any of these machines fitted with an engine brake.? AFAIK it was an optional attachment.
Amazing. A big flap and an apparent urgent need to get information/advice, then - crickets........ Sometimes I wonder why we bother.