JD 420

[JimAnderson]

Hello,
Looks like you did well from what I see.The 62 blade is desirable
and more robust than the 61.From what I see on the tracks the rails
look fairly new.The shots from the side of the surface that the rollers
touch have an oval dimple that I have seen only on JD replacement
rails.The pin bosses look new.It is difficult to see the condition of the bottom rollers so its hard to comment on them.You have a 40c sprocket
on the right side and a 420 on the left.You might want match the
sprockets to each other.The 40 bushings are 1.500 OD and the 420
are 1.562 OD.In my opinion the hard to find and expensive parts(tracks)
are quite good on your find.The engine issues are relatively simple
and cheap to address.Luck,JimAnderson

[tzbmcp]

broken adjuster - does it look like just a new huge bolt? hard to replace? will spring need to be compressed to replace?

[JimAnderson]

Hello,
The track adjuster is the long bolt inside the springs up front.I dont
think yours are broke.The bolt may be bent.The bolt-spring assembly
is preloaded to a given length.The remainder of the thread has the
two nuts that you use to adjust track tension.One nut tightens the
track and the other is a jam nut.Both track adjusters on each frame
needs to been adjusted at the same time.
One word of caution is that spring assembly is under pressure.While
adjusting the tracks doesn't affect preload trying to remove the bolt
from the spring does.There are plenty of spring -bolt assemblies out
there, so messing with the one you have might be more trouble than
its worth.
Count the number of pads on your tracks.If there is 32 then by
the looks of it you have a fresh set of pins and bushings.It is
so unusual for most to see a 50 year old dozer with new pins and
bushings that when they see it the first thought is that the front idler
is too far back.See if you can post a picture of the wear side of the
bushing where it contacts the sprocket.One clear shot says volumes.
Luck,JimAnderson

[tzbmcp]

Thanks Jim. On my way to count. 31 pads is bad right?

[JimAnderson]

Hello,
The four rollers with the oversize front idlers take 32 links.
Thirty one links means that someone took out a link to get track
adjustment if you don't have the smaller front idlers.Bushing wear
at the sprocket contact point will tell you a lot.Heavy wear in this area
not good,constant diameter from rail to rail,jackpot.
Luck,JimAnderson

[Paul Buhler]

The blade "U" bolts need to be replaced - on this side anyway. I just bought two. They were made up at a spring shop for $11 each - grade 8 steel-20" rods with threaded ends, and washers and nuts. The press man inserted a 1" X 1/2" steel dowel top dead center when bending which gave me the needed "V" shaped bottom. Good luck with your machine. From what I'm seeing, and your comments it sounds like a good deal if the initial price is right, and only you can know that. I find that having time and patience to shop around has saved me quite a bit of money on many of the parts I've needed for my 420.

[tzbmcp]

just got back to the dozer - 31 pads. got pics of the bushings will send.

[tzbmcp]

just posted pics underside of tracks. dont have anything to compare these too as Im new to these things. Counted 31 pads. thoughts?

http://s1086.photobucket.com/albums/j456/tzbmcp/

[JimAnderson]

Hello,
From the pictures you posted it appears you have done well
on the tracks.There seems to be almost no wear on the bushings
at all.The pads while a little worn are still have plenty of life in
them.I counted the pads based on what I see and came up with
32.I don't think you have the small idlers.In my opinion you
should change out the 40c sprocket if these are 420 rails.The
mismatch will cause rapid wear on both bushing and sprocket on
that side.There may be other mechanical issues with the machine
that will pop up over time ,be patient.Many times we hear " I just
bought this crawler ,fresh paint ,runs great steers to one side
only.By the way where can I get new tracks and how much?"
From what I see you seem to have a great set of tracks.
Luck,JimAnderson

[tzbmcp]

thanks Jim. I counted those things 3 times on each side and came with 31 every time. Sounds like if theres 31 then there'll be more wear quicker. Any thoughts why they might be 1 shy? Can I get one link for each side, and if so am i opening up a whole can o worms? When I counted 31 the other day I decided to walk away from it figuring that meant more hidden issues that Im unable to discover. Havent purchased it yet.

[Lavoy]

Bad and good that I can see offhand.

Bad. One wrong sprocket, pads are shot, LH front idler brackets, bushings, or axle are likely shot. 62 blade is very heavy on a 4 roller crawler, more so on a standard idler crawler, which this crawler is. This is made worse by the fact that is also has the wide moldboard. The winch/arch contraption on the back would place a terrible amount of stress on clutch housings, sideframes, and trans to center section bolts if they have been pulling from the upper pulley. Original seat is gone, or trashed, no fenders. Bad adjuster spring, no battery sheetmetal left.

Good. 62 blade in general is good. Rails appear to have been replaced in the past, and look good, RH idler brackets appear to have been replaced. Sheetmetal is not bad looking, has a grille guard.

In general, look over the back end of the crawler very closely, I would almost be willing to be that there is some damage somewhere due to the winch/arch combination. Check the finals for breaks or welds. Lift the front of the crawler off the ground with the blade, I would guess the most forward roller is trashed or close to it.

All in all, not a bad crawler if no damage is in the back half of the crawler, but I would not pay the price we discussed on the phone.
Lavoy

[tzbmcp]

Thanks.