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Deas Plant.
11-13-2003 12:36:21
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Hi, Sean. I have only operated one Komatsu D41S for about two hours although I have run the D55S's, D57S's and D75S's a bit more. If my memory serves me right - and it usually does, so far at least - the D41S I played with seemed to be a hydraulically controlled direct drive. That is, it had no torque converter but all the transmission functions were controlled by one lever. Fiat had a similar system on their early 'powershift' machines. It worked but you could not 'feather' the transmission for fiddly tasks like you can with either a real powershift or a stick-shift. Because the hydraulics run the show the transmission is either 'KLUNK', in or 'KLUNK', out. I stalled the D41S a couple of times before I got the hang of this. Other than the transmission set-up, I liked the D41S. It pushed well, handled well, was well balanced for a small loader and the bucket was quite 'controllable' or 'user-friendly'. I was thrown on it with no time to look around it to clear a road for trucks that arrived 10 minutes after I was given the job of clearing the road. Donchya luv pressure? As mentioned above, I'm not very familiar with the smaller 'Kummagutsa' line-up. What to look for in 941's and 951's. If a 941 has a ripper fitted (which it should or it is only 1/2 useful), you need to get underneath and check the ripper draught frame. The 'pull' for the ripper does not come from the mounting bolts on the back of the steering clutch case. These bolts are only designed to 'carry' the ripper. If you look underneath, you will see a triangular frame with the two outermost rear corners bolted to the bottom of the ripper mounting frame and the front corner of the triangle pinned to a bracket underneath the tractor that vaguely resembles an tractor drawbar anchor point. This pin should have ABSOLUTELY NO MOVEMENT AT ALL. The reason for this is that this triangle frame - henceforth known as the 'draught frame' - is supposed to take all the load of pulling the ripper. There are shims fitted between the rear of the draught frame and the ripper mounting frame. These shims allow for adjustment of the loading on that front pin when/if it should become worn. Check this pin regularly and, if there is any movement in it, remove shims from each side of the rear of the draught frame until it loads the pin up again when you tighten those rear bolts. If the load is not on this pin, you risk cracking the bottom of the steering clutch case when engaging in heavy ripping because it was not designed for that sort of load - it is not a D9. These cracks occur underneath where the floor of the steering clutch case meets the back wall and the first signs you will have of one are that there will be engine grade oil leaking out of the back end of the machine and the steering clutch case oil level will go down, probably slowly for a start. I never got underneath the back end of the 951 - it wasn't 'my' machine - but I think it is the same set-up. Other than that, check for wear lines around the track pin bushes where they contact the sprocket teeth AND feel around the opposite of the bushes too to see if there are wear lines there. If they are there, it indicates that the pins and bushes have been turned and are more than 1/2 worn out. Check track rail height. I don't have the specs for it but you can get them from a Cat dealer or somebody here may have them. If there are wear marks on the inner faces of the the pin bosses (the faces closest to the rail running surfaces) in the rails, both rails and bottom track rollers are worn. Accurately assessing the % of life remaining in a track system involves some serious measuring and having the full specs to compare with. Experienced people can get pretty close by eye and feel but it's not a game for beginners. Too many variables and too many things to consider. However, you will be able to get some idea yourself from the above and people like Bob/ont on this board are more experienced in this side of track matters than I am. Jack the machine up on the bucket and ripper (if fitted) and have a look at the rollers and general condition of the undercarriage frame underneath. Also check the front and rear track guiding guards, inside and out, and the rock guards, if present. The track guiding guards should have replaceable wear plates bolted to the insides of them to lead the track chain onto the idelr and the sprocket. The rock guards are long plates bolted to the underside of the track frame between the front and rear guiding guards to keep rocks, sticks and dirt or mud out of the rollers and to help keep the track chain correctly under the rollers. Tip the bucket forward slightly until the teeth or cutting edge is the only part touching the ground and the rear of the bucket is 6 inches or so clear of the ground. Now slowly raise and lower the bucket, just lifting it clear of the ground and then putting it down again until the weoght of the front of the machine comes on to it. This will allow you to check the bucket linkage pins and bushes for wear. If fitted, check the ripper pins and bushes for wear. This is not a CRITICAL point but does help to give some idea of how hard the machine may have been worked and/or how well it might have been maintained. Look ALL over the machine for cracks and places where cracks have previously been welded. If you have the opportunity - and you have the right to ask for it - get oil samples analysed and be guided by the results 'cos they will show what might be worn or wearing in the engine, transmission, steering clutch and hydraulics. If you are not experienced in crawlers, and it sounds as if you are not, taking a good Cat/Komatsu mechanic or fitter along with you might be one of the smarter investments you could make. Hope this helps. You have a wonderful day. Best wishes. Deas Plant.
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