John Deere 4300 complete rebuild

[Spudland_Dave]

One Q about your 4300.....I looked thru the thread and couldnt/didnt see it... How many hours are on the 4300 you're rebuilding?

 

[dfkrug]

How many hours are on the 4300 you're rebuilding?

The tractor is supposed to have between 700 and 800 hrs on it, but
I can not verify that until I fire up the instrument panel and read the
LCD guage. I am hoping to do that in a month or so.

 

[Spudland_Dave]

The tractor is supposed to have between 700 and 800 hrs on it, but
I can not verify that until I fire up the instrument panel and read the
LCD guage. I am hoping to do that in a month or so.

Wow...I'm thinking that ultimately, ABUSE was the culprit for all the damage, not so much "design flaw"....I was certian you were gonna respond with something along the lines of 2,000-3,000 hours.
A little while back I was looking at a 4500 that was rough...she had 1185 hours. Mechanically she seemed OK..didnt see any excessive play in the 3pt like your egged out holes...I remember that for certian because of all the "Aluminum housing" posts here I made sure to triple check that area..

Motor didnt start too easy and the LH front axle seal was shot....

 

[Lil43]

Wow...I'm thinking that ultimately, ABUSE was the culprit for all the damage, not so much "design flaw"....I was certian you were gonna respond with something along the lines of 2,000-3,000 hours.
A little while back I was looking at a 4500 that was rough...she had 1185 hours. Mechanically she seemed OK..didnt see any excessive play in the 3pt like your egged out holes...I remember that for certian because of all the "Aluminum housing" posts here I made sure to triple check that area..

Motor didnt start too easy and the LH front axle seal was shot....

The 4500/4600/4700 didnt have the aluminum axle housings like the 4400 and down so 3pt problem would be a lot less likely.


Doug nice thread ,very informative.Thanks for your effort in sharing.

 

[Spudland_Dave]

The 4500/4600/4700 didnt have the aluminum axle housings like the 4400 and down so 3pt problem would be a lot less likely.

I coulda swore it was a 4500, but it must have been a 4400 then because I clearly remember the "White Powderey" corrosion common with aluminum and you could see silver where the rear end was scratched... It was only a few months after I purchased my 3520 last year so I really wasnt "shopping to buy" or remember for that matter ...

 

[Volfandt]

Bump.....

 

[dfkrug]

In this series of pix, I am taking apart the 3-pt lift (rockshaft) hydraulic
system.

The whole rockshaft assembly, including the cylinder casting, is made by
Hema in Turkey...they also made the implement hyd pump and PS/charge
pump.

The service manual does not even talk about the internals of the valve
itself (made by Danfoss in SC), except to say that if the inline filter fails,
you have to clean it out. My filter has failed.

 

[dfkrug]

For some reason, my 4th photo in the last post did not take. Here it is.

Currently, I am in the process of removing the spline shaft from the
rockshaft housing. It does not just slide out, so I may have to lug it over
to the press.....

 

[Kernopelli]

My past experience ( non JD 4300) was that a heavy punch centered on the shaft end and a heavy hammer was all that was necessary. I would be surprised ....I often am, that it's not a true pressed fit.

 

[dfkrug]

...a heavy hammer was all that was necessary.

Good suggestion. Stepping up to a bigger "persuader" was all it took.

The bushings fit snugly over the spline shaft (rockshaft), but not so tight
as to require a press. Good thing, as I would need help to hold this
casting on the press bed if I went that route.

You can see the bore in the first two pix. The inner bushing seems to
have a plastic coating over a copper- or bronze-plated steel press-fit
bushing. My service manual has no spec on the wear limits here, maybe
because Hema has produced multiple variations for Deere. The book
talks about an outer bushing diameter of only 1.83" and mine is about
2 1/3".

Pressing these inner bushings out and replacing them may be a good idea,
but I would need help to hold the housing in the press. They may be OK
as they are. Another judgment call.

Also pictured are the rate-of-drop valve controller and the rockshaft
valve housing and cylinder head. Rust on both items has gotten inside.
Recall that this housing was covered by more than an inch of dirt (mud)
that caused the corrosion you see. Rust did not get past the O-rings,
however...that is good. In the last photo, you can see the piston. The
cylinder bore is smooth and the piston is quite snug, so I will not remove
it. Removal likely can not be done without damaging its seals.

Owners of these tractors should keep this hidden area under the seat
clean to avoid corrosion. Hema's paint adhesion is awful. I will be doing a
bunch of scraping, cleaning, and painting before all this goes back together.