Komatsu Dd41 s3 bucket pins and bushings

Voodooburner · Feb 1, 2022

Hello all. I just purchased my first piece of heavy equipment. I bought a Komatsu D41 s3 with a new engine in it. The undercarriage is excellent and runs well. The hydraulic cylinders were leaking at the seals so they have been removed and sent to the shop. The lower pins and bushings on the bucket and tilt cylinders are shot. Is there a goto place for these types of parts? I bought some property that had some thick areas of small pines I need cleared into pasture…..quote was 50-70k…so here we are!

Cat977 · Feb 2, 2022

Some fellows on here use off road equipment for parts. You may find the holes for the bushings have been pounded out of round on the outside edges. Measure them up before pushing in the new bushings in and check back if you like.

JimInOz · Feb 2, 2022

I was lucky enough to operate a D41S-3 in the late 80s.
Fitted with cabin,rippers & 4in1,it was a nice machine & did good work.
I hope your machine serves you well.

Voodooburner · Feb 2, 2022

It looks like the lower bucket pins and bushings took the brunt of it. I am guessing those bushings are welded in and will need to be cut out….but the good news is I bought it at a price that allows the repairs!

Cat977 · Feb 2, 2022

The lifting arms and the upper arms probably have replaceable bronze bushings. The bucket bosses probably solid steel. Think of weld up and line bore. You can knock down a lot of trees with loose pins. Accurate digging and grading is hard. You could rough it out and use a Dozer to finish it. Get some estimates on the bucket $$$$. How about sharing some pictures of your new girl?

Voodooburner · Feb 4, 2022

I bought her for pushing over trees, no precision grading needed. She needs a good cleaning from the hydraulic leaks…cylinders should be back monday….shop said they could make me the brass bushings and pins….of course I could use this as a great excuse to buy a lathe and mill. I think I did OK for 4,000

Cat977 · Feb 5, 2022

$4000 sure is a good place to start from. The machine is well sized you what your aiming to do. I couldn't see many for sale so future parts availably could be troublesome. If you have "ANY" doubts on oil or filters change them. You may get help on the forum but try to get at least an operators manual, it can tell you where to "clean out pickup screens", change filters and where grease points are. Try Ebay, the original manuals are much better than reprints. Just fix the runability issues for now. Then put it to work as close to the shop as you can and be aware of any changes in performance, or sound, or oil leakage. The bushings are bronze not brass. You should be able to buy pins and bushings cheaper than someone can make them, quality better too. Have fun taking your new girl out!

Voodooburner · Feb 5, 2022

Thanks! It came with new fuel and oil filters, I am trying to locate pins a bushings elsewhere

Voodooburner · Feb 20, 2022

So the hydraulic shop returned my cylinders….turns out the pins are 55mm the exact same diameter as the hydraulic pistons I just replaced…..the shop was like “we can make them or you can just cut them yourself and save 400 bucks”

Cat977 · Feb 21, 2022

Well now that's some real good news! Come to think of it I've bought bronze bushing/bearing stock from McMaster-Carr and other industrial suppliers. Buy and cut to length. You need room for the pin and grease around .010". drill the grease hole after you install, a grease grove maybe a good idea. Easier to buy made for your machine though. "You do not pound them in", you will mushroom the end. Press them or pull them in. Freeze the bushing and heat the arm top, bottom, front. Put oil on bushing and slid in place. Keep a flat piece of steel and a good sized mallet to convince it to go in straight.

Cat977 · Feb 22, 2022

When using chromed piston rod for pins, and bolts for a retainer on the bucket or arm. You want to grind a flat spot where the drill enters pin (chrome is very hard to drill normally). Using a mill or drill press to drill straight centered hole is preferred. Piston rod maybe case hardened use sharp drill bit and slow rpm's. If you aren't pulling chips out, your work hardening the steel. Stop before this gets going and resharpen drill bit. If you are pushing on a drill that's not moving for even a short amount of time it can become impossible to drill through without a carbide bit. Rotate the pin and start drilling from a new spot.

Cat977 · Feb 23, 2022

Hate to say it but I was ass-you&meing they are bronze bushings. They are harden steel or something very wear resistant, you should get washers/shims to take up the extra room between the bucket ears to keep the dirt out and grease in. If the old bushings aren't too bad I'd think about putting it back together as is or just replace the pins.

Voodooburner · Feb 23, 2022

Old bushings were destroyed….I will get pics tomorrow….its pretty lol. I soent some time yesterday adjusting the shift linkage….it didn’t want to go into neutral. There is a bit of slop in the shifter. My shop manual tells you to measure the throws but nit the adjusting procedure.

Welder Dave · Feb 26, 2022

Even if the pins have .005" clearance they should slide right in when aligned. I had new pins made for my backhoe swing post and they were about .005" clearance.

Voodooburner · Mar 20, 2022

Yay! Got my pins made up, cylinders installed, working in reducing the slop in the shifter, it doesn’t want to go in neutral, shifts fine on the transmission, something weird going on between the top of the shifter and the bottom connection to the linkage, I replaced a wallowed out roll pin but still has some slop

Komatsu Dd41 s3 bucket pins and bushings

Voodooburner

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