Broken bolts where track assembly fastens to frame

[neilh]

Picture below for reference.

On my 1965 jd-350, I have discovered an issue with the bolts mounting the track assembly to the frame of the tractor. There is a bracket on either side of the tractor with each bracket having two bolts on the side and two bolts under the frame. Half of the bolts are missing, and the other half are broken off. I did find one bolt that was still in the frame, but it was bent, and it snapped off when I tried to remove it.

Based on the single piece of the remaining bolt, it appears to be a 5/8" coarse thread with a lock washer. This brings up a few questions.

1. What was the original length of this bolt?

2. What grade bolt was this supposed to have been.

3. Are all of the bolts in these brackets(side and bottom) exactly the same.

4. Is the frame piece actually threaded, or was there supposed to be a bolt on the far side?

5. If the frame is threaded, is there clearance to drive the broken piece out forward, or is the only hope backing all of the bolt fragments out.

6. Is there a chance that this can be done just with an extractor through the bracket holes, or will I likely need to remove the tracks and their brackets away from the frame in order to be able to cleanly work the broken pieces out?

7. I'm not exactly sure when these bolts fell out. The tractor had a pretty easy life, and it has been mostly idle for the last twenty years. Nothing appears bent, but should I be looking in a specific spot for certain kinds of damage?

[Jim B]

I may be wrong but it appears you are looking at the crossbar. Here is a link to the on line parts catalog for the 350. https://jdparts.deere.com/servlet/com.d ... anguage=19. Search model 350 and select 350 Crawler Tractor (PC921). There are several different sizes involved. Locate the bolts you are looking for and you will find the sizes and lengths of most of the bolts shown in the parts description. Many of the bolts in the area you are looking at are grade 8, so they may drill hard. There is also the possibility that some have been drilled and tapped oversize in it's past life. In you have an account set up with a JD dealer you should be able to see a description with the grade when you put the part number in the part number search on the homepage. If you don't have an account I don't think you will see that information. If you get the numbers you are interested in and need; post the numbers and I will check the grades for you.

It is not uncommon for these bolts to be loose/broken/missing. You might get them without taking things apart. An easy out may work. Removal methods and success vary greatly when dealing with broken hardware. Also check the bolts holding the engine through the transmission case to see that they are in place and tight.

John Deere used a hardware code for the grade in some cases. Here is code info for fastener regular grades copied from the parts book.

A17A Has the strength of SAE Grade 1
A17B Has the strength of SAE Grade 2
A17D Has the strength of SAE Grade 5
A17F Has the strength of SAE Grade 8
A17G Strength is 10% to 20% greater than SAE Grade 8

Hope this helps to start.

[neilh]

There were only two bolts remaining in the cross bar. One of the bolts(5/8" x 2 1/8") had the standard grade five marking. The other bolt was the broken one. It drilled very effortlessly making me suspect grade 2. However I doubt that either of the bolts are the originals.

The parts that I am missing are(key values) 19+20's, 17+11\s, and the 21 shims.

Also what makes the washers 'special'? Based on comments from jdparts.com, I am guessing that the washers are just a nearby metric size.

So what is the verdict? Should I just use grade 5 everywhere and hope for the best?

Should I add lock washers to everything in an attempt to keep the bolts from working their way out?


From the table on p65 of John Deere JD 350 Crawler Tractor Parts List PL-T23824T(which exactly matches jdparts.com):

[Jim B]

Using description I see using my JD sign in and the hardware info I posted before:

19H2473 is a grade 8 hex head capscrew.
19H2592 is a grade 5 hex head capscrew.
T21228 washer is 0.531" ID, 1.125" OD, 0.180" thick, Material shows as 1045F which I expect would make it grade 8 to match the capscrew.
T19584 washer is 0.669" ID, 1.339" OD, 0.157" thick, Material shows as 300HV which I expect would make grade 5 it match the capscrew.

T20892 subs to T34493 (NLA either). 0.036" thick is equal to 20 gauge mild steel. You could use the Bar, key number 26, shown in the on line catalog as a pattern to make them.

The special on the washers may be thickness. With the dimensions you can find some to match htem.

I would use Blue Loctite rather than lock washers.

HTH
Jim

[original possum]

Also check the rear end of the side frame where it fastens to the clutch housing as those like to shear at the same time. Be advised that you CAN remove the side frame from the machine easily unless the belly pan captive nuts break their cage.

[neilh]

Removing the side frames is definitely the way to go. I have removed the right side without too much trouble and removed the broken bolts.

However the left side is giving me fits. It appears that the side frame is caught around the side of the engine+clutch housing which prevents me from lifting the frame out of the crossbar.

Is there a secret(like a special slot) for getting the left side frame off?

[original possum]

With all the bolts out of the crossbar you can jack up the front of the crawler, lifting it off the crossbar until the side frame until it clears. Then hold your nose just right and cuss at it.

[neilh]

I used a jack right in front of the crossbar on the clutch housing, and the engine, clutch, reverser, and transmission all started to rotate.

I just about have enough clearance to get the side frame out of the crossbar when the free movement stops. If I jack any further I actually start picking up the front of the tracks.

So is there something else that I have to remove in order to get free rotation?

[original possum]

All I recall from this part is the severe bleeding from my right thumb. I think we pried the top over the cowl (panel under dash) and then cussed a lot. Make sure everything (like clutch spring) is disconnected.