The continuing saga of the trashed CT332 final drive. The cost of parts to rebuild are way high so we are moving on to replacement. Machine has 2100hrs and is in decent shape. A new drive from John Deere is 4100$ and no core charge. No one has any rebuilds in stock. Folks have to send their broken drive in to be rebuild. The round trip freight cost makes this option too expensive. Texas Final Drives has a pair of new aftermarket drives for 5500$ plus shipping. Couple things about these aftermarket drives concern me. One is replacement/service parts, they don't have any. They don't use the machines brake line, it gets capped, the drives have internal brakes. I'm not familiar with these, can someone school me? Finally all the hard lines are replaced w/hoses. I don't see the hoses fitting under the protective covers and would be exposed. The machine is used in the woods a lot where running over 2-3" trees is common. What do you think? Here is a pic and video from TFD of the aftermarket drives
Those motors (and pumps) won't last long running the machine at idle....
Care to explain?
If it isn't a direct fit replacement, I personally would not do it. Nothing good, in my mind, can come from altering the way the machine was designed and built to run.
Only general info here, sometimes the manufacturer makes a part defective by design and refuses to update it for whatever reason. In that case aftermarket might be better than new if they can figure out the design problem and make it better. Otherwise I agree with KSSS 99% of the time.
That is a good point. The aftermarket coming to the rescue of the MTL undercarriage by Blair Industries would be an example of that. The case mentioned about drive motors seems to me to be beyond that, but I am not familiar with the Deere drives, maybe it is a better solution. Seems to be a pretty drastic departure from the OEM drive however.
I think MG is referring to the fact it sounds like the guy is operating the machine at very low rpm if not at idle which is one the worst things you can do because if the low pump pressure at low rpm.
Can you explain why operating a machine at low RPM and Low pump pressure is a bad idea?
Yes, please explain. With certain implements, I find they work best just above idle. I would change my usage if that is harmful to my machine.
I am not sure of the exact details why or what it does, but I know I have read on several occasions that it's not good to operate them at low rpm. I'll have to thumb through my owner's manual again but I seem to think I may have seen something in there as well about it, but i may be wrong. My assumption would be that you you are probably going to overwork the hydraulic pump by putting too much load on it without enough pressure. For the hydraulic experts on here, is that assumption incorrect??
I retract my statement about not lasting long so let me clarify. The Sauer Danfoss series 42 pumps that are in the CT332 (if it is mechanical controls and not an EH machine) requires a minimum of 500 rpm to operate so normal idle should be enough provided that the minimum charge pressure remains above 250 psi when operating. When it becomes an issue is when the engine might be lugged down below 500 rpm or if there is some wear in the pumps that would allow the charge pressure to drop below the 250 psi mark then you run the risk of losing your lubrication film and consequently could have metal to metal wear of the rotating group which is never good. If the machine never drops below the above thresholds then the pumps and motors should last without issue. But since their is no gauge so you can see what your charge is doing I recommend that skid steers as a whole should be run off idle. I would think 1000 rpm should give a good safety margin and not be too fast for any attachment.
Hey MG, so when you say 1000rpm should not be too fast for any attachment, are you referring to stationary attachments like post hole diggers and such? I know I have read on several occasions people saying not to operate these tracked machines at low rpm, as far as actually moving the machine I assumed. I do not operate attachments on mine, so my above comment was based on the guy in the video driving the machine at low rpm. I know on the few occasions I have moved mine at low rpm, say 1500 or so, it does not sound like a happy camper. My assumption would be that if you operate the unit too long (in regards to actually moving the unit) at lower rpms, your hydraulic pressures and flow rates would be low, in turn building to much heat in the fluid and cooking components such as drive motors. Is that assumption incorrect? I know what they say about assuming, so I usually prefer not to do that, but I know my machine sounds like it does not like life at low rpm which gives merit to the statements I have read about not operating at low rpm.
RPM is performance and has little bearing on system and component life. Change oil and filters at the manufacturer's specified recommendation and run the machine anyway you like. You can't hurt it by running slow or fast. You are more likely to hurt yourself running the machine wide open if you are not a skilled operator.
So flow rate and cooling rate of hydraulic fluid is not affected by rpm?
Ok just went back and re read through my owners manual, I must have dreamt I read a warning in there about not operating at low rpm cause I dont see anything. Disregard my prior statements, I'll shut up now.