John Deere 4300 complete rebuild

[dfkrug]

Wow, getting those brake levers off was tough!

I have a pretty good selection of gear pullers, but none would do the job.
I tried heating with a torch, soaking overnight with LiquidWrench under
puller tension. No dice. My final choices were to weld some ears onto
the lever tube (for better gear puller grab), or to drill holes and use bolts.

In the first photo, I drilled and tapped for some bolts. In the second, I did
the other side by drilling for bigger bolts, and using nuts.

The third photo gives you some idea of the pressure put on the brake shaft.
Both the shaft and my puller use hardened steel....it seems the puller bolt
was just a bit harder.

Why were my levers so much harder than Kyle's to remove? I can see that
the lever tubing has rusted just a bit inside. My roll pins, BTW, are made of
a single piece of steel, rolled up in a double-thick spiral. They were a bit
rusty, too. None of this rust was visible externally.

 

[dfkrug]

There is a cleanable second filter, I suppose it could be replaced but the book does not mention a replacement cycle unless I've missed it.

This is the main hyd suction filter, the only filtration the implement pump
uses. Maybe that is why JD resorts to more steel mesh inline filters, as
found between the SCVs and the rockshaft valve. IMO, a hyd system
replaceable element 10 micron filter (in addition to the HST filter) is
superior.

 

[dfkrug]

Replacing everything would indeed make it cheaper to buy a new tractor, certainly not the point of rebuilding.

Here is my philosophy regarding buying new parts in a rebuild. Others may
have different standards.

I replace all shaft seals if they are leaking at all, regardless of cost. I
replace all shaft seals if they are not leaking, if "reasonably" priced. Some
seals will be damaged if removed, or compromised if you pull a dirty shaft
thru it. Valve stem seals get damaged if removed....you can actually
see the damaged rubber barb if you look. What is reasonably priced? Hard
to say, but I am not going with new rear axle seals at $25 each and they
show no sign of leaking.

I do not replace head bolts if not rusty, despite recommendations to the
contrary. New engines may use "special" bolts that are designed to stretch
once and once only. Never had to deal with those yet, as far as I know.

I replace all bearings that show ANY sign of being compromised. I check
them by cleaning, then rotating them while feeling for any uneven resistance
or spin noise. I use solvent to remove the old oil, but I do NOT use
an air gun here. I have replaced 3 bearings so far in this project.

The HST parts you mentioned, I would change if they were not so pricey. I
have also changed my mind and will go with the original water pump, cuz the
new one is $204. The old one is not leaking, but it does not spin as easily
as a new pump. It is easy to replace later, however.

 

[gbw]

This is the main hyd suction filter, the only filtration the implement pump
uses. Maybe that is why JD resorts to more steel mesh inline filters, as
found between the SCVs and the rockshaft valve. IMO, a hyd system
replaceable element 10 micron filter (in addition to the HST filter) is
superior.

Yessir. It's hard to imagine 'overfiltering' hyd. fluid.

I hope nobody inferred that I'd question your judgement in any way, 'cause I don't. I hope I'd never be so presumptuous. I was curious about how you approach the question, and I very much enjoyed your well thought through philosophical answer. I can't wait to see the finished tractor!

 

[Kyle_in_Tex]

Just remember, I recommend replacing the rear axle seals. It sure is a lot of work to get at them.

 

[Johndeere3720]

WOW. I just love to read this thread. Ive been camping lately so i've not been able to have much seat time. Luckly I might get some tomarrow. Thanks for documenting such an interesting restore.

 

[dfkrug]

I hope nobody inferred that I'd question your judgement in any way

No worries! I welcome all constructive questions and comments!

It is purely a judgement call on some parts replacements. I did agonize
over some of them for sure, but you do have to draw a line somewhere.
Kyle may be right about the rear axle seals, for example.

 

[dfkrug]

Now that the brake levers are off, I can remove the axle housings. All
moving parts inside the final drive will have to be removed and cleaned due
to all the metal fragments in there. It is amazing that there is little
damage.

In the second photo, the axle is out....what a big gear! You can see the
even polish of the contact surfaces of the gear teeth...looks good. The
axle itself is over 2" in diameter. This is where all the torque is maximized;
it is good to see robust components here. No bearings were bad, even
the Russian ones out near the hub.

In the third and fourth photos, I have removed the wet brake components.
They are not worn out, so I will reuse them. There are some aluminum
fragments between the last plate and the aluminum disc basket, so that
will have to be cleaned up.

 

[Spudland_Dave]

I tried heating with a torch, soaking overnight with LiquidWrench under
puller tension. No dice.

Put the LiquidWrench away and start using Kroil...After seeing it work in action, I buy it by the case...

 

[Scooby074]

Put the LiquidWrench away and start using Kroil...After seeing it work in action, I buy it by the case...

+1.

Kroil is probably the best out there.