NEWBEE komatsu d31s-16 changing the hydro shift filter and fluid

drkonek · Oct 2, 2012

Have a 1982 komatsu d31s-16 track loader and it seems to run out of power when I attemp to move it . like it is slipping. The steering brakes go soft and it slips in and out of drive fwd and reverse no matter what speed I have it in. Once it is warm it does not move at all. When I start it there is a whishing noise until I put in gear and then it gets quiet. Is there a way to tell if it is sucking air and where do I look? Can you tell me where the filter and drain line are and how to get at them. I removed the plates at my feet but do not see a filter for the trans. There is a filter in the battery compartment but I think that is for the hydralics, am I right? I have the parts manual and the shop manual but it only lists a screen. I ordered a repair and operations manual but it has been 2 weeks and I still did not get it. If I need to get at the bottom can I drive it up on railroad timbers to get under? Thank you in advance for any assistance I am new at this but a good auto mechanic so I will tackle anything.

J_J · Oct 2, 2012

If you think you have a suction leak, look in the hyd tank for air bubbles.

cbailey1956 · Oct 2, 2012

I have a d-20 but it is is pilot controlled not steering brakes. The tank and filter in the side compartment are for the loader controls on mine. I have 3 dipsticks under the seat/ foot area for drive fluids. Yes you can drive it up on timbers to gain bottom access. The first time you pull a pan please have it supported and balanced with a rolling floor jack before taking off the last bolts. It will be heavy and usually loaded with years of grease, oil, and dirt. I have a complete d31e-20 manual and find it very thorough.

drkonek · Oct 8, 2012

Thanks for the help. Removed the rear pan and got the screen out of trans, it is full of little pieces of material almost like a gasket, Could this be a trans band and what do I do next. rebuilt the trans or buy a used one? any ideas as to where and how I look for one/ Thank you again.

cbailey1956 · Oct 9, 2012

To clarify I have a d31-e20 not d20. Anyway did you ever get your shop manual? The screen was covered with the material? This it not unusual to find material in you filter / screen. What was the quantity and sizes of material. What condition was the oil in? The material could be brake lining or clutch facing? It may not be enough to matter at this point depending on how old the oil is. Could you describe your controls. Pilot / joystick or all levers and foot pedals? Brakes need to be adjusted correctly either way.

drkonek · Oct 9, 2012

the material is maybe 1/2 inch and 3/8 inch wide hard like an old gasket, the oil is clean and the filter does not look too bad. I took some pictures and will try to include them. I have brake pedals for steering and the man I bought this from just spent 2-3 thousand on a brake band repair at a dealer. It was his fathers and he passed away. It hardly takes any foot presure to steer this. I have a 3 speed fwd and reverse joystick.

cbailey1956 · Oct 9, 2012

Sounds more like pump or control valve issue rather than clutch packs. Probably 5 clutch packs, 1 for each speed and 1 for fwd and one for reverse. Pressure to them would be by a control valve managed by linkage from your levers. might have a modulating valve that controls pressure surges when starting/shifting. I do not know if you have a inching pedal for that model. It could also be controlling pressure to the clutch packs. The whoshing noise sounds like a suction issue. Can you identify the transmission pump. probably mounted behind or on the side of the trans housing behind the damper engine drive. It would be great to find the operating pressures and check the pump output. Have you refilled it after cleaning the screen and checked operation. I would lean toward pump pressure rather than clutch pack since it would be unusual for all of them to go at once. Assuming this drove proper when you got it. You might try posting again in the construction forum as there are probably more views there than here.

drkonek · Oct 9, 2012

Thank you for the info. Where is the construction forum? Do you think the pieces in the screen are from the pump and should I even worry about them? I have a fellow bringing a bore scope so we can see inside the trans and maybe see what is going on. If I clean the screen and refill it I could check the pressure and this might show me the problem if we cannot see anything with the camera setup. I will keep you updated.