Komatsu D31

[Frankly]

Just purchased this dozer today. PO did not know the SN and I can’t find it either. The only numbers I see are on the blade. They are MK-90-031E-256 and right under these numbers are 114-72-43101. Does the 031E indicate it is a D31E? Decals say D31. The PO said that the fellow he bought it from said it was 1998. I have not removed the covers to find an engine number. Would that help in identifying it further? I am wondering if I will be able to find parts with no SN/Year?

 

[southernman13]

I have a D31P. The sn plate is down by the floor under the seat and under the drive handle. If it’s missing it could be stamped where the plate was. Idk. If it’s a narrow or standard track machine then yes it’s a d31E. The 31P has wide tracks (LGP bottom). Mine is a 96. S/N46628. I also have a D41P and the sn on it is stamped on the rear of the machine under the fuel tank. What engine do you have 4 or 6 cylinder. Good luck they’re great little machines

 

[Frankly]

I believe it is a 4. I will try to get time tomorrow to do more looking. I believe the tracks are the narrow ones. It has a small 8’ blade.

 

[Kyfarm]

post some pictures of it.

What are you gonna do with it?

 

[Frankly]

Going to clear 25 acres of brush and small trees. I have determined it has a Model # 6D95L-1 engine (6 Cylinder). I still cannot locate the SN.

 

[JimInOz]

The 6 cylinder came out around 1985-86.I think the E models were extended track frame.
The 4 cyl models had a Serial Number stamped on upper LH side of steer case.
The 114-72-43101 number usually indicates a part number.Google search says it's a bracket.

 

[southernman13]

That’s the same engine I have. Mines a 96’. Very good engine

 

[John C.]

As I recall the D31 was a 4 cylinder, D37 was a 6 cylinder with no turbocharger and the D39 had the turbo charger. All I believe were the SD95 base engine.

 

[Frankly]

So mine is a D31 with a 6 cylinder (6D95L). The blade has a number on it MK-90-031E-256, which leads me to believe it is an E. It has the 15 1/2” width tread, which I think is standard. I was hoping to find SN so I can buy an operating manuel to be sure of all of the nuances, but I am not confident enough of the model number to buy one. I see a number like 16, 18 or 20 at the end of the model number (i.e.,D31E-18). What does that mean? If I buy a D31E-18 will that be close enough?

 

[JimInOz]

In the Loader version the D31S -16 series had a 4 cyl engine (4D-105). The 17 on,I think,had the 6 cylinder.
A Komatsu dealer should help with finding the Serial number & history.
There was a guy selling CD manuals on eBay,otherwise Tradebit might help.
The Operator Manual has serial number locations,plus maintainence info.

 

[southernman13]

Any pics of the machine this may help. I know the 31 has a 6 cylinder non turbo and some had the 4 cylinder w turbo. I guess defending on the series. Yes the dash number is the series mines a -20 D31P-20 E models have narrow track pads. P models have the wide LGP pads

 

[southernman13]

This is our old girl lol. D31P-20. She’s ain’t purdy but it’s and incredible little dozer. Just never misses a beat.

 

[Kyfarm]

my '92 D31E-20 S/N 42058 has a 4 cylinder turbo. motor runs great, book says its a S4D102E-1, southernman's has a higher s/n so I'm guessing they went to 6 cylinders later in the series run. My track pads are 13" but my brochure shows 15 1/2" track pads as an option for D31E-20.

Its an original brochure for D31E-20/D31P-20. Brochure shows a printed date of 11/97. It does NOT show any information for a 6 cylinder in a D31E or P -20.

 

[John C.]

The 102 engines are Cummins clones. They came into use after Komatsu took over the Dresser line of dozers. The E model machines were a standard track gauge. The P model machines had the track frames extend out a bit to be able to use the wider pads without them hitting the machine frame.

 

[Frankly]

Thanks for all the info. I am thinking that this is a D31E-20 - likely 96 to 98 (a PO said it was a 98). I may try to order something along that line to see if my thinking is correct. I will also look for a Komatsu dealer.

 

[Frankly]

Here is a picture of my new toy.

 

[southernman13]

Yep basically looks like mine! Probably is a -20

 

[mike_belben]

My D31P-18 is pretty hammered but still pushes its heart out. No meter, but it has enough hours to have worn out and broken the original komatsu trunnion pivot on the blade which was replaced by a prior owner with a cat D3/4/5 trunnion, worn out, welded up once then worn out by me and getting welded up again.

I dont know how many hours it takes to kill 3 trunnions but the thing fires the second you push the button and pretty much all works as it should with just basic shade tree maintenance.

Stay ontop off all the control rod linkage pins and clevises, which will get grooves worn in them and then inconsistently steer and try to drive through the brakes. Simple fix by just drilling up to the next american size pin or bolt to restore the tolerance. be sure the finals arent full of milky oil either. If you have to stomp to steer, stop and fix it before you chew the brakes off.


Great machine, will do a ton of work per gallon of fuel. I built a bolt-on semi-u corner for grubbing stumps last week and am floored that it doubled productivity in clearing sub 10" trees.

 

[Steven Wincentsen]

Thanks for all the info. I am thinking that this is a D31E-20 - likely 96 to 98 (a PO said it was a 98). I may try to order something along that line to see if my thinking is correct. I will also look for a Komatsu dealer.

I have the same dozer only a LGP Dresser. I found a factory manual on e-bay for $70.00.