John Deere 4300 complete rebuild

[mjncad]

The subframe is now mounted. It was quite tight, securing the front
hinged plate that holds it on. That was due to the material I added
a while ago to compensate for wear. There is no looseness now, that's
for sure. I have also bolted the plate closed, as the rental yard did. This
keeps the FEL from being quickly dismounted, which is no problem for me.

If your 420 or 430 FEL is loose, I recommend this easy fix.

My attempt at fixing my loose loader wasn't as successful as I had hoped. Please see Loose 430 Loader shim fix - Page 2 - TractorByNet.com

 

[dfkrug]

My attempt at fixing my loose loader wasn't as successful as I had hoped. [/url]

Sorry to hear that, Matt. Why did you go with the shims instead of just
welding a bead along the support surface, then grinding? I would shoot
for having no wiggle at all, to reduce future wear.

I was wondering.....do all the 420 loaders have no bucket links like this
430 loader has? I also notice that the 430 loader does not seem to tie
the QA brackets together, as my 420 does with long 1" rod. This photo
was snipped off an eBay listing.

 

[jpinca]

Well, I am quite disappointed with the construction of the JD 420
loader's quick-attach bucket mechanism. It seems they used no wear
bushings to secure one side of the pins, so there is significant wear
in the thin 1/4" retaining holes. You can see in the first 2 photos that
bushings are used on one side to keep them from rotating. Clearly they
should have used bushings on the other side, too. You can see in the
third and 4th photos how much wear I have. I can't leave it that way.

If I weld bushings onto the places where none exist, I will need all new
pins, because they are not long enough. Not a big problem, normally, but
the upper pin is a 1" rod that spans the width of the loader boom.
At least JD uses mild steel pins (unlike Kubota, who uses hard pins), so
wear is shared fairly evenly between the holes and the pins. Another
solution would be to cut the worn holes out to 1.5" and weld in half inch
thick 1.000" DOM tubing. Or I could build up the hole with a weld bead,
and drill it out to 1.0". Decisions, decisions.......

I've got a similar issue. I'll leaning toward welding in some DOM.

How are bushings in heavy equipment usually constructed? Is there some replaceable bearing material that could be used? How about a sealed ball or roller bearing?

 

[kennyd]

Sorry to hear that, Matt. Why did you go with the shims instead of just
welding a bead along the support surface, then grinding? I would shoot
for having no wiggle at all, to reduce future wear.

I was wondering.....do all the 420 loaders have no bucket links like this
430 loader has? I also notice that the 430 loader does not seem to tie
the QA brackets together. as my 420 does with long 1" rod. This photo
was snipped off an eBay listing.

410/419/420 picture first, 430/460 picture second from JDParts:

 

[dfkrug]

Thx for posting the parts dwgs, Kenny. It looks like the upper rod (#8)
on the 430 I posted has been tossed out. That's a mistake as the
loader boom arms need to be tied together so they don't get twisted.

Having the links is nice, though.

 

[dfkrug]

I've got a similar issue. I'll leaning toward welding in some DOM.

How are bushings in heavy equipment usually constructed? Is there some replaceable bearing material that could be used? How about a sealed ball or roller bearing?

I am sure you have the same issue.

These holes are for stationary pins, but the 1/4" surface width is too
narrow, IMO. The best fix is DOM and new pins. I am leaning toward
welding and drilling, as well as filling in the depressions on the pins. I
should bring this back to as good as original. If you use DOM, it will be
better than original.

The rest of the FEL uses DOM welded thru extra large holes, rather than
DOM welded to the outside, next to 1 inch holes. So JD did a good job
there. None of the FELs I have seen or owned used inner replaceable
bushings. Many of the backhoes do. I would be very surprised to find
any ball or roller bearings used for these pivots.

 

[dcyrilc]

Well, I am quite disappointed with the construction of the JD 420
loader's quick-attach bucket mechanism. It seems they used no wear
bushings to secure one side of the pins, so there is significant wear
in the thin 1/4" retaining holes. You can see in the first 2 photos that
bushings are used on one side to keep them from rotating. Clearly they
should have used bushings on the other side, too. You can see in the
third and 4th photos how much wear I have. I can't leave it that way.

If I weld bushings onto the places where none exist, I will need all new
pins, because they are not long enough. Not a big problem, normally, but
the upper pin is a 1" rod that spans the width of the loader boom.
At least JD uses mild steel pins (unlike Kubota, who uses hard pins), so
wear is shared fairly evenly between the holes and the pins. Another
solution would be to cut the worn holes out to 1.5" and weld in half inch
thick 1.000" DOM tubing. Or I could build up the hole with a weld bead,
and drill it out to 1.0". Decisions, decisions.......

You have my attention here. The bucket on my 2240 has a very similar problem. My problem has to do with having 1/4" on both sides and the holes being totaly egg shaped. I probably have pin wear too, but haven't pulled the pins to look. As I have never done anything like this before, I'll be watching very closely to see how you make the repairs.

 

[mjncad]

Sorry to hear that, Matt. Why did you go with the shims instead of just
welding a bead along the support surface, then grinding? I would shoot
for having no wiggle at all, to reduce future wear.

I was wondering.....do all the 420 loaders have no bucket links like this
430 loader has? I also notice that the 430 loader does not seem to tie
the QA brackets together, as my 420 does with long 1" rod. This photo
was snipped off an eBay listing.

My 420 doesn't have the links. I wonder if they give more curl angle, or if they were used in order to use the same cylinders as the 420 on a longer frame. I'm thinking links were cheaper than having another set of cylinders to manufacture and inventory. Just guessing mind you.

As for using shims...it just seemed like a cleaner, more precise installation; but as I said in the other post on shimming the loader, I need to do more investigation.

 

[Spudland_Dave]

I wonder if they give more curl angle, or if they were used in order to use the same cylinders as the 420 on a longer frame. I'm thinking links were cheaper than having another set of cylinders to manufacture and inventory. Just guessing mind you.

The links are there to make the bucket curl forces "stronger"....without the links when the cylinder is totally extended the leverage is less because the 2 pivot points are so "close together" because of the rotation of the bucket. With the links, it allows the force of the cylinder to "round the bend" and still have alot of leverage. Dunno if I am confusing you...this all makes sense in my pea brain...dunno if I put it on paper elegantly :confused2:

 

[jpinca]

My bucket pivot and cylinder mounts are egged out too.

Has anyone directly compared the 420 to the 430?

I'm curious exactly what the differences are. I'd consider turning up the PRV to get better lift performance, but I worry about pretzeling my 420.