John Deere 4300 complete rebuild

[mjncad]

So those are new. I bought the
3rd SCV lever from JD, but not the OEM cable, bracket, or contol lever.
I plan to make my own setup for that.

I'd like to see what you come up with as I have the OEM cable controls for the 3rd, 4th, & 5th SCV and they leave a lot to be desired in my opinion.

FYI, the third SCV kit number is LVBM19694 and it may or may not be available. The 4th & 5th SCV kit number is LVBM19535 and supposedly I got the next to the last one in the country. I believe the PB kits are still available and the kit number I have is LVB25221 and I paid $307 for it.

 

[dfkrug]

I'd like to see what you come up with as I have the OEM cable controls for the 3rd, 4th, & 5th SCV and they leave a lot to be desired in my opinion.

For the 3rd SCV, I already have a push-pull cable, and I will make a bracket
similar to what comes in the kit. I don't see the value of the friction
operating lever on the fender, however. I have never seen one installed.

For the PB connection, that is easier. I want to use a hose instead of
hard lines with QA fittings that allow me to connect the pressure side to
a hoe, and the hoe return to the sump, bypassing the 3-pt cylinder.

Both of the kits are absurdly expensive for what you get.

 

[mjncad]

For the 3rd SCV, I already have a push-pull cable, and I will make a bracket
similar to what comes in the kit. I don't see the value of the friction
operating lever on the fender, however. I have never seen one installed.

Here is a link showing the hydraulic kit installation I did, which illustrates the fender mounted levers. Picasa Web Albums - Matt - Hydraulics Up...# My gripe with the cable is that it is a 1:1 motion with the valve spool, while the Quadra-Stat (brand name) lever assembly has lots of motion available to it. The 1:1 motion makes it tough to feather the valve, which is why I'd like to come up with a mechanical linkage arrangement to take advantage of the lever's range of motion, while operating the spool within its parameters.

What drives the kit prices is the Deere name and the design that went into making the kits fit with minimal fuss. I don't have your wrenching skills, so installing the kits was ambitious for me; but the biggest hassle I had was buying them. I only had to make a couple of minor adaptations for things that didn't fit quite right.

My gripe with the PB and 4th & 5th kits is because there is no PB port on the rockshaft valve, Deere had to kludge a compromise design to power the 4th & 5th SCV's via the PB before powering the rockshaft.

 

[dfkrug]

The 1:1 motion makes it tough to feather the valve, which is why I'd like to come up with a mechanical linkage arrangement to take advantage of the lever's range of motion, while operating the spool within its parameters.

Very nice pix, Matt!

I went back and looked at them closely. I have scribbled on one of them
to show what I am doing. The 3rd SCV cable bracket and the PTO lever
bracket that goes on top of the valve are visible in your pix, which is more
than I can say for the manual. I bought (rather than made) the PTO lever
bracket cuz I did not know precisely where it went as my bracket and
lever were missing. These brackets often run $60 or so, so I make them
myself if I have enough info.

I will make my version of the "OEM cable bracket" and I will drill a new
pivot hole in the 3rd SCV "bellcrank". Is the original pivot hole what gives
you the 1:1 motion you are talking about? It is true that the moment
arm ratio between the pivot and the spool is about 1:1; I am increasing that
to about 1.5:1 with a new pivot. My cable has plenty of stroke and the
spool has a very strong internal spring.

You are right that all your cables and hoses make quite a rat's nest! As
you found out, even the factory setup causes some interference.

 

[kebo]

Dave, how about a picture or two of the tractor in its present state?? Just want to see what it looks like at this stage of reassembly?? At least, I think you are in the process of working to get it back together. All of the detail pic's are great, but some showing the big picture occasionally are good to! Thanks for the great job on documenting it too. JD should hire you as a Sr technical writer for their tractor manuals.

 

[Johndeere3720]

Ive read every post in this thread and it has inspired me to restore a tractor myself. There is an Allis Chalmers 5015 I would love to fix. I guess it has an engine problem. My only problem is where will i fix it? I only have a small bay in the garage that I could use.

 

[dfkrug]

OK, here comes the final assembly.

First is my rear end and gearbox. Getting those axle housings on is not
easy....you have to line up the splines of the brake system and get all
the shafts thru the right holes before the silicone gets tacky. But
they are not heavy anyway.....that's the only reason I am glad they are
aluminum.

I am going to try to do these in order, so stay tuned.

 

[mjncad]

Very nice pix, Matt!

I went back and looked at them closely. I have scribbled on one of them
to show what I am doing. The 3rd SCV cable bracket and the PTO lever
bracket that goes on top of the valve are visible in your pix, which is more
than I can say for the manual. I bought (rather than made) the PTO lever
bracket cuz I did not know precisely where it went as my bracket and
lever were missing. These brackets often run $60 or so, so I make them
myself if I have enough info.

I will make my version of the "OEM cable bracket" and I will drill a new
pivot hole in the 3rd SCV "bellcrank". Is the original pivot hole what gives
you the 1:1 motion you are talking about? It is true that the moment
arm ratio between the pivot and the spool is about 1:1; I am increasing that
to about 1.5:1 with a new pivot. My cable has plenty of stroke and the
spool has a very strong internal spring.

You are right that all your cables and hoses make quite a rat's nest! As
you found out, even the factory setup causes some interference.

I hadn't thought about adding a hole to the bellcrank like you are planning on doing. What I've been thinking about doing is replacing the cable with some sort of 'Rube Goldberg' series of levers and rods to allow near full movement at the operator's lever, which is probably a 60-degree arc; but step down the total movement when it reaches the spool. Right now it's not a high priority item, so I just dabble with it in my mind.

 

[F-I-T]

Have you used the JD kit, FIT? That is good experience. My earlier JD
cyls used glands that were retained by inside snap rings and the JD kit
was over $40. Lots of "extras" in the kit, too. I don't buy the factory
kits anymore....I would rather order from a place like Hercules.

Yes, I installed two JD kits on the bucket cylinders of the 420. No real extra parts in those kits. I have a 70 loader on my 855 that uses snap rings to retain the guide bushings that you can remove easily, and a 1955 era 45 loader on my 70 Diesel that is another design again, but all of them have been repaired with JD kits. I travel 48 weeks a year, so I just order from Deere and the parts are there when I get home for the weekend.

Thought others would like to know trick of the filler ring for rod removal. Your "Hercules" kit probably didn't include that.

 

[dfkrug]

Thought others would like to know trick of the filler ring for rod removal. Your "Hercules" kit probably didn't include that.

I have not had to do that (yet), so it will be a learning experience when
one comes up. My old JD cyl was for a 70A FEL on a 955. I have not
bought from Hercules yet, but their catalog of seals is extensive and the
prices reasonable.