John Deere 4300 complete rebuild

[dgruber]

My 1999 John Deere Compact 4200 now has 1706 hours and the plastic hood and side panels are shot! Running strong.
I have been lucky that it has been a work horse for me.
Just broke the lift arm while attaching my JD # 9 sickle mower to the 3 point hitch.
Is their a good after market for the 3 point hitch assembly? I have another 10 acres to mow and bale ASAP!
My baler is a JD 14T square baler with a Wisconsin engine.

 

[dfkrug]

Lastly, I think the locking differential is meant to disengage if you take your foot off. Especially if the torque is relieved on the axle. I guess I'm trying to say that you should keep your foot down on the lever until you are sure you don't need both wheels driving. I wish you could see what a new one looks like to compare. I'm worried that your locking won't hold up or last. I'm also guessing the part is high dollar.

The diff lock on my B21 was in great shape (more than 2000 hr, too), due
to a better design. They are designed to stay locked until the torque
on each wheel evens up. Then the spring disengages it. No big deal if
the user has to hold the diff lock pedal down. Sometimes you have to
do that anyway.

That part is the whole diff housing....I am guessing it is $400-500.

 

[dfkrug]

Just broke the lift arm while attaching my JD # 9 sickle mower to the 3 point hitch.
Is their a good after market for the 3 point hitch assembly?

I have bought after-mkt 3-pt parts from AgriSupply in NC, and they are
quite reasonable. I assume you did not break the upper rockshaft lift
arm.....that's a pricey bit from JD. I have also bought the Heim joints
(swivel eyes) from AgriSupply to be welded on.

Have you considered welding up your broken arm? Or having it welded?

How are your lower 3-pt arm swivel holes on the rear of the tractor doing?
Are they much bigger than the original 7/8"?

 

[Johndeere3720]

Hi. I really enjoy this thread and the holes are still their original shape since the tractor typically doesnt have an implement on the back.

 

[dfkrug]

Here is the tunnel casting, which houses the 3 drive shafts, plus the
MFWD shifter shaft and fork. You can see the needle bearing for the
MFWD shaft.

Another JD 4x00 just came up in eBay with a broken tunnel casting,
also from backhoe use. This seems to be the weakest park of these
tractors when using the factory backhoe supports, which offer no
protection from bending moments. Bradco makes a much better subframe
to avoid this problem (thanks, WOOD911, for sending the Bradco subrame
info).

 

[dfkrug]

And here it is...after boiling it all down, this is what is left: the naked
final drive gearcase.

This is about 200 lb of cast steel, going for the final wash. At last, I get
to put all this back together.

 

[Johndeere3720]

Well today I took a magnet out to the tractor to see what its made of. I found out that the rear axle is alumimum. The 3 point, PTO, front axle are all steel. I still am very interested in this thread and cant wait to see the finished product.

 

[dfkrug]

Here are the roll pins that Deere uses in some places. They are a double-
wound single piece of spring steel. I have shown the new one and the old
one. The latter gets dirt in the center, making it look solid. Add a bit of
rust and this baby is very tough to remove (and install). Some roll pins used
are the conventional type, like the one on the right.

Can anyone identify the other part in the photo? I found it in the bottom of
the final drive gearcase. It is a cylinder that is clearly punched out of a
plate of steel, then precision ground to be exactly 1/8" thick.

 

[dfkrug]

Well, here are my axle housings....all welded up. Although the left one
was still functional, it was worn quite a bit, and the holes were no way
near the original 7/8" size.

I went to a guy I know who is a retired ex-Navy certified welder who did
all the work. He milled out both housings so he could fit some 6061 Al
2.5-3" cylinder stock into the resulting holes. The right side with the
broken out pieces used a larger diameter chunk of 6061....you can see the
edge. He chamfered the welding area, then TIG welded everything. Then
it was back to the milling machine to align-bore new 7/8" holes.

The 6061 aluminum was originally tempered, but likely lost that in the
welding process. The cast aluminum in the housing is of unknown alloy, but
it is likely that durability of the new 6061 pin holes is somewhat greater
than it was in the original casting. Each "ear" is also about 1/2" wider at
the pin holes, too. The fix for both housings cost me $400.

I cleaned up all the corroded areas, washed it thoroughly, and painted
it black. Ain't it purty?

 

[mjncad]

The axle housings look good. That must have been a pain for the guy to weld between the ears.

I still for the life of me don't understand why Deere chose aluminum for the axle housings. I don't think any of us will ever know why the engineering team chose that particular material.