JD 120 general rebuild thread, bushings, pins, CWS thumb wedge QC bushings, hoses

skyking1 · Nov 15, 2020

In an effort to cut down on thread count, I will try running everything in this thread now. Let me know if that works for you all.
My next job after the tracks is the boom pin/bushings/seals and lower boom cylinder bushings. Those are the most beaten.
I am planning on doing the bushings in place, lifting the boom enough to scarf out the old and freeze in the new.
My chicken-eye sees about .050 maximum movement at the chassis. I can live with that and skip the line boring there.
The bushings are far gone, on the other hand.
Should I presume the pin to be bad? I can pull and check it before ordering up one.

Bls repair · Nov 15, 2020

I’ve always put pins and bushings in as a set . New parts matched with old worn parts puts extra wear on new parts.

skyking1 · Nov 15, 2020

duly noted and I agree on principle.

skyking1 · Nov 21, 2020

New pin and seals on the way from the John Deere dealer, and I found the bushings elsewhere for a pittance. They are new open box an properly tagged with the hitachi part number.
I will open it up and see if the boom is wallowed out. If it is, I can put it back together with the old parts and make a date at a machine shop for the job. I have a $5400 quote to do the big end of the boom up, line boring both the house and boom.
I will ask for the add on price of line boring the small end and the stick while they have it apart.

skyking1 · Nov 23, 2020

There are 5 nasty looking hoses at the boom base, and a couple that look like they were changed. It has the optional separate return line for the hoe pack, that one is OK, and one of the pricey hoses looks like it was changed.
Dealer said they are in the 400-450 dollar range, each. They have long metal elbows and are not conducive for a typical hose shop build.
I got into the catalog and googled, and found all of them but one for less than $300 each.

skyking1 · Nov 23, 2020

I measured the rotek at about 1/8" play.
The boom cylinder pin bosses on the house are hammered out pretty bad.
I pretty much decided that this machine is only going to get bushings and pins and minimal repair to tighten things up.
By the time I got done having everything line bored, I'd be about 20 grand into it.
I don't think the owner of the company is ready for that, and I can dig with it the way it is.

skyking1 · Nov 23, 2020

The bushings arrived today! They have a little bit of surface rust, but that's easy to clean up with some Scotch Brite. There are two variations, one has a central grease groove and small helices coming out, the other one has big helices cut in it with no central groove. I imagine the big helix one is the later revision. It certainly has better support without that big groove cut out of the center.
I'll clean them up and post some pictures.
John Deere wanted $175 each. I got these four bushings for $100 shipped. I figured if I messed something up I have spares

skyking1 · Nov 24, 2020

The dealer wanted 16 hours to r&r the boom. That's $2,500 on the bill. after they got it out they wanted $800 per setup on line boring.
Two setups for the cylinder bosses and one for the boom bosses on the house. One setup for the boom bore itself.
If I pull the boom blank off the hoses and roll it up onto my trailer and take it down there I'll save the $1600.
A part of me really would like to rebuild it completely. If I get a newer machine, most of them are going to be 135 sized and I'll need a new trailer too which sucks. The 120 does fit a special spot in the equipment line up the way you can haul it with two axles.

skyking1 · Nov 24, 2020

I realize I am just talking to myself in here, but that is normal. Too much time alone in the cab I guess.
I stopped by to order up the hoses and some bushings, and went back to talk to the service manager. He said he knew where I was coming from, he hears all the time " we might be trading it in next year so we don't want to dump a lot of $$ into it".
He was very gracious about it, and suggested that some heat might restore some of the bores on the house, if they were not too bad. Try the new pin, he said, and try some heat.
I am driving back to the shop and realize what he meant by heat. He just couldn't say " toss a couple of strategic hot weld beads on it and see how it shrinks up"

JDCrow · Nov 25, 2020

I’m listening

JDCrow · Nov 25, 2020

I would have loved to have a 135. I’ve ran a few over the years. But your absolutely right. The 120 is a sweet spot. Big enough to have decent reach, load trucks, and weight/width is good. You can get them into fairly small lots and will run a 2000/2500 lbs hammer, which can chew through a lot of rock.

skyking1 · Nov 30, 2020

Still waiting on pins, bushings, and hoses.
I took off the cutting edge on the 4' cleanup bucket, and will be taking it to a machine shop to straighten out the bottom of it.

I will scarf off most of the wear plates to facilitate an easier straightening and they are shot anyway. One of them is peeling off like a sardine can tab

mitch504 · Nov 30, 2020

What are you using to transport this 120?

skyking1 · Nov 30, 2020

20 ton tandem tilt with a 20' deck and about 7' of tongue. Trailer weighs about 10K. Behind a L9000 Ford with 3406B and 15 speed.
Trailer is at 38,500 gross and I put about 5000 of that on the pintle. That keeps those axles at under the 34K rule.
That's one of the reasons I like the 120. Towing with a pair of axles, that trailer is a lot more 'fun' than any 3 axle I have drug around.

mitch504 · Nov 30, 2020

sounds good

skyking1 · Nov 30, 2020

I had a local hitch shop weld on a class V 2.5" receiver down below my big pintle so I can tow my little 16K trailer for the mini. I installed a brake controller for that last week, and built a flat 7 pin to round pin whip adapter. It will be much nicer than lugging the 20 ton around with a mini on it.
The 16K has a 4' fixed porch on it for the tools, just a much nicer setup for the mini. I have 3 buckets and a hoe pack for it. On the 20 ton all that sat up on the nose and I'd have to mash it down with the bucket to walk on.

mitch504 · Nov 30, 2020

I have a friend who has an ex RR service (F800 I think) truck set up like that, except the receiver uses 3" solid square ball mounts.

skyking1 · Nov 30, 2020

The shop added a 3" box tube to the bottom of the rear plate to get a good height. He angle cut it to match and boxed it in on the ends, I thought it was a great job for $300 plus the price of the new pintle.
Then I took a look when I was running wiring with the bed up.
He also made some beefy knife plates that reached up onto the existing plate, and back to the extended tube. It was a great job by a pro and one of those times it was better than money well spent.

JDCrow · Dec 1, 2020

Ahhh Ford 9000. Those and GMC Generals had great interiors And drove great. I don’t know why they didn’t stick like the other manufacturers

the 3406 and 15 combo is a great set up as well.

JDCrow · Dec 1, 2020

And that bucket is gnarly

JD 120 general rebuild thread, bushings, pins, CWS thumb wedge QC bushings, hoses

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Well-Known Member

Well-Known Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Senior Member

Well-Known Member

Well-Known Member