Repairing a damaged and loose 420 loader on a JD 4300 tractor

[dfkrug]

This thread will show the repair efforts I went through to fix a sloppy
FEL on my 4300 ex-rental tractor. This is a chapter in my refurbishment
project on this tractor:
http://www.tractorbynet.com/forums/parts-repairs/247806-2001-john-deere-4300-hst.html

This loader is the smaller of 2 OEM units available from JD for the 4200/4300/4400
tractors, as well as some of the 4x10 CUTs. The bigger one (430) has larger
cylinders with larger rods, as well as "kidney links" on the bucket end of the
boom. Those 2 improvements would reduce the chance of needing some of
these repairs, IMO.

The most obvious problem with my FEL was its looseness. I could shake the
vertical masts left and right and get more than 1/2" of movement with
the boom at rest. The JD quick-attach bucket brackets had been bent and
repaired, probably from operating the boom without both brackets fully
engaged on the bkt, or possibly when a pin fell out.

Furthermore, the bucket itself was bent, some cylinders leaked, and one
had a bent rod.

The good news: the boom arms were not bent. I have seen bent booms before,
caused by renters ramming the tractor into immovable objects. That's
a difficult fix.

When I got the FEL off, the first thing I noticed was how worn the subframes
are. Even the locating key has a deep groove in it.


The mast itself is cast steel at its base (3rd photo), with 7 contact areas.

Each was significantly worn or mushroomed. 'A' indicates where the
locating key goes, and it too had lost a lot of material. I filled it in with
a weld; it was about 1/4" deep.

 

[Iplayfarmer]

I'm looking forward to seeing the progress on this repair. It looks like you have your work cut out for you.

 

[dfkrug]

Those who looked at my FEL repairs for the last 4300 saw that I just
filled in the wear depressions on the 2 subframes, ground them down,
and I was gold:


Most of the wear on that FEL was where the longest of the 7 contact areas
was. After I ground the welds down to be planar, I mounted the loader
and it was nice and tight. Boy, was I fortunate on that one.

So, I did that for this one, laying beads on nearly all the depressions. I ground
them down and mounted the loader. Not even close. I needed to do lots
more welding and grinding, fitting, and mounting/dismounting.

So, I removed the subframes and did all the adjustments and test fittings on
the unmounted loader. I probably did 12-20 weld/grind/mount/dismount
iterations per side. Fortunately, doing this on an unmounted loader was
not too hard.

In these photos, you can kind of see the added metal between the contact points.


I know that JD offers weld-on shims to do this kind of fix, but this loader
required more steel under some contact areas, versus others.

I am quite happy with how it came out. After mounting the subframes back
on the tractor and installing the FEL, the masts can not be wiggled at all.
If your masts wiggle, I would say fix the problem now, before it becomes a
Big Problem.

 

[dfkrug]

The next thing I did was to remove all four cylinders and empty out the
old hydraulic fluid. I needed to spend some time with some large wrenches,
straightening out the bent hardlines on the boom, as well as scraping out
pounds of old dirty grease.

One of the bucket cylinder rods was slightly bent, so I took apart the
cylinder and straightened it in my press. I can see that both of the bkt
cylinders have had replaced rods at least once already. I recognise the
handiwork of the local hydraulics specialist. I can also see that piston
seals on 2 cyls have been replaced (they don't look like JD OEM).

I fully rebuilt one of the boom cyls; it had a broken gland retaining
wire, which I repaired like on the last 4300. JD rebuild kits for the cyls are
about $25, which is way lower than some other JD kits.

All four of these cyls have 25mm rods, which are very susceptible to
bending. The 430 loader uses bigger rods, which is much superior.

I have no new pix of this process; here is one from the last 4300:

 

[dfkrug]

Now, I set my attention on the bucket. It was a bit bent, at the upper lip,
and the lower mid-carcass area.

I used my trusty 20T air-over-hydraulic jack, and careful placement of
various and sundry chunks of steel (1-in plate and 4x4 tubing, mostly).

The upper lip came out well, and the lower part is better, but not perfect.
Hard to see in the photo (3rd one). The cutting edge is very straight.

 

[dfkrug]

Next, I had a sorry pair of QA bucket brackets to repair. They were
both twisted and bent (probably from a pin coming out), and one
of the pin holes on each was very sloppy. You can see how the pin
fits into the hole in the second photo. Poorly.


You can't tell from the photos, but the sides of both brackets have
spread out by about 1/4".

First thing I did was to take some very large adjustable wrenches
and untwist the sides of the brackets. They are only 1/4" thick, so
it was not hard.

My repair of the sloppy hole was different this time. Last time, I
welded in additional material to make the holes smaller, with a
carbide cutter for adjustment. This time, I decided to weld in a 5/8"
piece of DOM tubing so I would have a bushing on BOTH sides of
the bracket. (I don't understand why JD neglected to use bushings
here, since they did so for the rest of the loader pins.)

I used a template and my plasma cutter to make the hole bigger,
then I welded in the bushing. It worked out well, and it was easier
and better than the way I did it on the earlier FEL.


Finally, I welded in a brace to keep the brackets from spreading. If
anyone else attempts this, make sure you are clear of the cross-tube
zerk fittings, over the full range of travel.

 

[dfkrug]

Final notes on the FEL repairs:

There are four bolts on the forward section of the loader frame that
allow some adjustment. In the photo, I have removed one of them.
Mine were all somewhat corroded. There was not nearly enough
adjustment to take up any noticable amount of sloppiness in my
loader. But if your FEL is only off by a bit, try these first.


One TBN guy I know of completely swapped out the problematic JD
cylinders for stronger units with thicker rods. He has also added
bushings to his loader QA brackets as I showed here. Check out his
YouTube videos:
Upgrading John Deere (FEL) Loader Cylinders Part 1 - YouTube

Sadly, his tractor was stolen last year (MARS1952).

 

[RoyJackson]

Great posts, DF!!!!

 

[BRBurns]

I know that JD offers weld-on shims to do this kind of fix, but this loader
required more steel under some contact areas, versus others.

I am quite happy with how it came out. After mounting the subframes back
on the tractor and installing the FEL, the masts can not be wiggled at all.
If your masts wiggle, I would say fix the problem now, before it becomes a
Big Problem.

My 4300 with 430 loader is quite loose. I'm not seeing the wear you are, but there is a large gap on the mast mounts. How tight should that be? JD offers shims for that? Do you have any info on the shims?

My loader will move side to side with a load on it as I do over bumps, so I'm Thinking I should fix it.

Thanks,

 

[dfkrug]

My 4300 with 430 loader is quite loose. I'm not seeing the
wear you are, but there is a large gap on the mast mounts. How tight should that be?
JD offers shims for that? Do you have any info on the shims?

My loader will move side to side with a load on it as I do over bumps, so I'm Thinking
I should fix it.

You want it to be tight enough that you can not see/feel any wiggle, fore and aft or
left/right. The longer you wait to fix it, the more fixing it will need.

As for the shim kit from Deere, CHUCK4310 bought and installed one here:
http://www.tractorbynet.com/forums/john-deere-owning-operating/152571-loose-430-loader-shim-fix.html

Discussion of my last 420 loader fix starts at post #227 of my last 4300 thread:
http://www.tractorbynet.com/forums/parts-repairs/146974-john-deere-4300-complete-rebuild-6.html
As I mentioned, that fix was MUCH easier.

If shims will work, I don't see why you need to buy them from JD.

Since you and Roy are both fortunate enough to have the 430 FEL, does it also not
have bushings on one side of the bkt QA brackets?