b79holmes

Member
I have a JD 2040 but don't know anything about crawlers.
If I look at a running 420C what should I look for?
I have read various dozer forums but can't say i totally understand what to look for for excessive wear on track components.
I'm not looking to work it hard but as a collector and light work piece. 50% wear is okay I think but not sure.
Any simple guidelines ?
Thanks,
Bill
 
When you go to see the machine put your hand on the engine to see if its hot, when starting note how easy it starts and runs, let it warm up a bit, remove the oil filler cap and see what the blow by is like, it will have a bit but it should not be like the exhaust, check the exhaust for excessive smoke, check the drive train, see it drives ok in all gears, see it steers, see what ever attachments are on it work, have a good look at the tracks, look at the bushes in the track chain, (the part that comes in contact with the sprocket) they should be nice and round and not worn through, check the sprocket teeth if they sharp they are worn, check the rollers and the idlers, there is going to be a bit of ware in used machines, abuse and neglect are the machines worst enemy.
AJ
 
(quoted from post at 22:59:57 07/22/21) Do tractors of this vintage have an hour meter and what hour is considerd rebuild time?

Some of them had hourmeters, but it would be nothing I would use to make a judgement with. They regularly got changed when they quit, or were just left inactive.

If the pads have two bolts in each they are correct for the vintage and most likely well beyond 100% worn out. You may still get a good bit of usage from them if they stay on. The common replacement for them now is to use JD 350 tracks (four bolts in the track pads) and undercarriage parts (sprockets require a rim replacement to do this). If it has 4 bolt pads they would be for a 440IC/ICD or later, as that was the start of JD using 4 bolt pads.

Measuring internal wear is one of the the correct steps in checking track chain wear. You should read through the article below, while it was written for Dresser, the info applies to most all under carriages and will give you a bit of understanding of what to look at and for.

http://www.tpaktopc.net/files/undrcarguide.pdf

And an important thing to remember with crawlers that has been said many times before: There is no such thing as a cheap crawler.
 
They may have hour meters, but seldom still work, and no way to tell when they quit working. Or if they are working, doubtful they have been working without stoppage for the last 60 plus years.
Lavoy
www.jdcrawlers.com
 
Concerning the hour meter - I have a 420C, and it shows around 280 hours on the meter. It said that when I bought it 35 years ago. I don't think they like the vibration.

Concerning what to look for on a used dozer - I recommend hunting down an old retired or nearly retired lifetime dozer operator to take with you for the look-see. Buy him and his wife the best steak dinner in the area as repayment for his knowledge and recommendations. It will be the very best money you can spend on this project, even if [or especially if] you don't buy it.
 
When I worked for the JD dealer the old guys liked it because I became the crawler guy.I was 21,they were 38 and 44.The two cylinder crawlers are all by themselves,if you could find somebody that knew them they could point out 50 things to look for.Couple of big ones are,the bolts that go through into the sides into the bellhousing.They will loosen and take out the casting and sides.Then the bolts holding that casting to the trans will loosen,and take chunks out of the casting.The big rivets that hold the crossbar mounts to the side frames will loosen up,you will see a lot of them welded.The square crossbar that the machine sits on will get loose too,it has rubbers that crumble and squeeze out,.Look closely at all the final drive castings.If they were run loose they can be cracked,or broken.Lots of them are welded.Not the end of the world,just see how good the job was done.These were built to be crawler tractors,NOT bulldozers.
 
We went to see the machine. Overall in pretty good condition.
1. One of the large idle wheels was damaged on the inside edge. Initial thought was rot from sitting a long time but it could have been rocks.
Is this normal. Is it a huge problem? For us as hobbyists if the machine is 60% worn out it will still last a lifetime.
2. The tracks are very smooth. No cleats at all. Is this a certain type of track? Would it impact its traction significantly ? Would this make it impossible to move in snow?
Bill
 
(quoted from post at 23:14:27 08/01/21) We went to see the machine. Overall in pretty good condition.
1. One of the large idle wheels was damaged on the inside edge. Initial thought was rot from sitting a long time but it could have been rocks.
Is this normal. Is it a huge problem? For us as hobbyists if the machine is 60% worn out it will still last a lifetime.
2. The tracks are very smooth. No cleats at all. Is this a certain type of track? Would it impact its traction significantly ? Would this make it impossible to move in snow?
Bill

Damage to the idler is likely from impact after being worn thin. Is it normal, yes it can be, if worn out and/or has seen impacts. The idler should be replaced.

The pads (plates on the track chains) are worn smooth. That is a sign of high wear. Depending on the type they were there should be 1 tall grouser (on a dozer) or three short ones (loader use). The grousers are like tread on tires, no tread, no traction. Most likely it would have poor performance in snow. It might move it self but forget pushing or pulling anything.

Yes, an undercarriage at 60% would last a hobbyist a long time. Sight unseen, from your description and questions here, I would say the undercarriage is not at 60%, but well beyond 100% worn out, and then some. Did you read the article on undercarriage I posted the link to for you? Did you measure anything or just eyeball it? Without making the proper measurements and comparing those to the manufacturer's specs, your percentage number is just a number you, or a someone, chooses to think it is. It has no verifiable basis to establish the actual percent worn.

The parts, like idlers can be replaced, there are some used ones out there, that may be better than the ones on it, but they will be worn for the most part. Like anything once and a while, a NOS one may turn up, but that is rare. You can contact Lavoy, at the link he gave you, he may have the parts you would need, he works on those crawlers.

New 420 undercarriage parts are pretty much NLA. If you wanted to renew it the fix is to go to 350 undercarriage parts for idlers, rolls, chains and pads. The 350 sprocket rims have to be cut off, fitted and weld to the 420 sprockets after those rims have been removed. A proper undercarriage renewal could be in the $5000 range.

Sorry if some of this sounds harsh, but your description says worn out undercarriage to me. They are good little crawlers and can be fun. They can also be money pits, look with your eyes open.
 

cvphoto96252.jpg
 
(quoted from post at 08:17:36 08/02/21)
<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto96253.jpg>

Teeth are not worn to a point?

Yes, that is a stone in your other picture. They get caught like that at times. Idler is likely thin and breaking up along the edge.

True, the sprockets aren't worn to a point, but it has wear and sprockets are only one part of the undercarriage system.

The pads are 2 bolt, so it hasn't been converted to 350 chains, and they appear well worn as you had posted. Grouser stock can be purchased and welded to them.

What is the condition of the flanges on the bottom rollers? How much external wear on the bushings? What is the internal wear measurement across 4 pins?

Just to give you an idea of what the percent of internal wear equates to (measured across 4 pins with the track forcibly stretched tight). 420 chains New = 23", 25% = 23.09", 50% = 23.2", 75% (recommend point for turning pins and bushings) - 23.34", and 100% = 23.5". Maybe the chains have been turned, or pins and bushings were replaced. Maybe your 60% is close. I'm just saying measuring is the only true answer, eyeballing is just guessing.

Does this crawler have a blade? Does it have a reverser? If so is the handle for it on the left or right side? The front belly pan is not on in your picture. Is it available or missing? Is the rear one there? Those protect the underside. Any attachment like winch or 3 point hitch?

Bottom line is if you are happy with what you see, the choice to purchase is yours, regardless of whether or not it is within specs. It may be fine to meet your plans. Many are way beyond the 100% worn measurement and still run for years. I have run some that way. The percentage worn is more a guide for when to turn the pins and bushings, and more critical if it is a working crawler for a business. They can be run until they just won't stay on, which can be a long time; if an operator is careful and keeps them adjusted.
 
>>>Jim.ME
Yes I read the first half of your document and my son read it all.
First one we have ever seen for sale reasonably close by and cheap. It was worth a look.
My 60% was a guess based on the rear gear teeth not being worn to a point.
It had a high lift bucket at one point but no longer.
No blade, PTO or 3-point hitch.
Not the original engine either but I forget what it has now. My son will remember.
It was not too far from us and reasonably priced but it does sound like a money pit and we will pass.
If anyone is interested in a running (it started right up) parts machine (is that fair?) it's in south east MA, Craigslist or Facebook Marketplace,
I'm not sure which, my son found it.
He's asking $2,000.
I can post a link here if anyone is interested and if I can find it.

Thanks again as we need to return to earth.
Bill
 

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