I recently bought a Cat 303C CR. The machine has 5k hours and both final drives seem to operate ok but they are slower than seems normal. I was doing service and checked the oil in the right final. It was dry and when I pumped full of 90, a small amount of tar like goop came out. No metal but really thick like cold peanut butter and jet black...and it stunk bad. Then I noticed all the 90 was draining out the face seal as fast as I put it in. As a temp fix I pumped a tube of bearing grease into the final so I could at least use it a bit until I can fix proper. Considering the time / effort to reseal that final, I plan to replace the final and motor. Since they have 5k hours, I will replace both sides. My question is: There is a huge price difference between OEM and aftermarket? I can get aftermarket with a 2 year warranty and I am leaning toward this. Is there a solid reason why I should not go aftermarket? Other comments welcome.
Have you thought about repairing it yourself
Gear box failure, especially the floating seals, does not require drive motor replacement, even though they are together as a unit. Either you have gearbox failure or motor failure.
Yes, I am able to repair this but my concern is that since it was run dry long enough to scorch the oil, the gear box is probably damaged. My other concern is the slow performance of both finals. The machine really doesnt like to pivot in place and I usually have to either jockey one track at a time or lift one track...5k hours. The low performance/speed and weak pivot tells me the drive motors are worn. I could tear the right side apart and inspect the gears but if they are bad then my downtime is very long. Thats the point of my post. Considering the issues and the hours, what is the best approach to this?
Do a casedrain oil flow check, anything more than 1litre a minute is a indication of a worn rotating group in the motors. Your planetary drives maybe ok.
Without knowing the state of the components it's impossible to make a decision. First find out whether the motor or the drive box (or both) are farked. As Tones said, do a case drain flow test. That'll prove whether the motors are good or not.
I will attempt the case drain flow test, hopefully this weekend and report back. Replacing the face seal seems easy enough and by far cheaper although labor intensive. How many hours are considered lifespan for the gear and motor?
I've got mini excavators with over 10k hours with untouched, save for oil changes, final drives. Only had to do duocone seals in one TB180FR @ 7k hours.
I've got mini excavators with over 10k hours with untouched, save for oil changes, final drives. Only had to do duocone seals in one TB180FR @ 7k hours. Teardown here...all blue print are images, click on each to fill page. 303.5C and 303C Mini Hydraulic Excavators Machine Systems Final Drive and Travel Motor - Disassemble Caterpillar avsmanual.com
Awesome, thank you
It’s amazing what a bit of regular maintenance can do.
2 qt of oil every now and again saves thousands. Proved time after time with little excavators and ctl.
The smaller the size of the compartment the more important oil changes become.
My minis get 90w in the gearboxes every 300 or 600 hours, depending on the jobsite (lotta tramming or not).
I've been on the every engine oil change way but in wet and mud caked jobs or like you said lots of travel more maybe we'll advised
Yeah, I just bought this a few months ago. I am pretty good with my maintenance but I can't undo it's history. From what I can tell this was owned by 3 construction companies before me and possibly been in rental at some point. I have started a small excavation business to keep me busy as I plan to retire in a few months so I'm just looking to make this reliable. For the most part it's in good shape. No leaks to speak of and runs good.