jd420 pics

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Stan Disbrow
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Re: jd420 pics

Post by Stan Disbrow » Fri May 09, 2025 7:05 am

Hi,

In the main power feed to the switch.... This makes me think the thing in question is an auto reset circuit breaker to replace the busted fuse holder.

You still have the two-bobbin (relay) mechanical voltage regulator for the generator?

The other thing it might be is the older style Cut-Out relay for the older style three-brush generator. But that's not supposed to be in the main feed line to the battery. It's supposed to go from the switch to the generator field coil. And that wasn't used any longer by the time the 420 came out as I recall.

The older switch, on the M, has a resistor built-in. That's for Low vs High charge rate on the three-brush generator (which has low output even on Hi Rate which is why the M only has two lights and not three). I don't recall a resistor inside the later ILBD switch, but there may have been a variant that did. My 58 420 had the sealed beam to the rear with the second lamp for Red. So a second wire from the Dim terminal of the switch.

The earlier type may have had a resistor internal to the switch for the Dim position.

Stan
There's No Such Thing As A Cheap Crawler!

Useta Have: '58 JD 420c 5-roller w/62 inside blade
Useta Have: '78 JD350C w/6310 outside blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (5045D), 2025 3025E

dtoots1
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Re: jd420 pics

Post by dtoots1 » Fri May 09, 2025 5:45 pm

Stan,

Had to put a new voltage regulator in...cannot recall now if even had the old one or it was beyond help when they broke original dash console..but dang metal box we lookin for was still there....however i am tending to believe is some sort of resister etc being on that mainline..and console fuse s/b in that new line once i can take a look inside dash...or maybe take pic of fuse/ign switch etc..will be out and in it tomorrow.

anyway..gonna leave that piece out.

being kinda new and tight the old 6 volt...showing 6.55 volts dont wanta push it over very well...will jump her w/12 in a.m. and see..

what shop ended up doing was...putting sleeves in and honing to fit my pistons and rings and polished crank to fit slightly used main standards w/new rod bearings..so essentially is back to original from factory, far as size...and yes head/valves done..new radiator too..starter and generator done as
well..and left steering / brakes all new..carb rebuilt too..full test on stands once she starts/runs..oops no muffler but old cherry bomb should fit purty red one too

another adventure!

dtoots1
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Re: jd420 pics

Post by dtoots1 » Sat May 10, 2025 7:25 pm

OK Guys,

Here we go...engine starts. runs, oil pressure in safe (green) zone...temp. gauge appears to work...have to put 12 volt jump box on to start..
hydraulics work...but couple leaks..1 no pressure return hose to reservoir needs replaced..bad and leaking...now the major issue...will have to see if that leak..actually ran down to the bell housing as i am finding oil dripping down from there......elsewise i suspect could be a rear main seal not set properly and leaking???? reported to my technician...will see what he thinks...


Other is loader lift cylinder out around the rod..so new seals etc in order..Lavoy do you have available???

Now also..will have to get blamed clutch back up to par.....cannot get it into gear ..as obviously not releasing...could not figure out how to pre set the blamed thing to be close while engine was out...since i had taken everything apart and cleaned em up..will see if need take down again if tech feels main seal could be bad...though i sure feel that he did put new in it...will see..

any suggestions on getting clutch close to release?...crawler still up in air so can still do drive test..

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Lavoy
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Re: jd420 pics

Post by Lavoy » Sun May 11, 2025 9:11 pm

Check with local hyd shop.
Lavoy
Parts and restoration for antique and late model John Deere crawlers.
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dtoots1
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Re: jd420 pics

Post by dtoots1 » Thu May 15, 2025 6:43 am

Well TechGuy came and peeked at her/.///used his borescope in bell housing.....and finds...camshaft plug partway out and leaking oil....so pull apart again this Saturday..and pull flywheel to get to it...sure hope things go well...will see..stuff happens

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jimmydiesel
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Re: jd420 pics

Post by jimmydiesel » Sat May 17, 2025 8:55 pm

While the engine is out maybe you can find the clutch not releasing problem. Check to be sure the disk is not in backwards. BTDT.
440 ICD 602 Blade 3Pt.hitch.
440 ICD 602 Blade Gearmatic winch.
440 ICD 64 6 way Blade Carco winch
440 ICD 831 Loader
440IC 831 Loader
1010c Diesel 612 6 Way Blade
North Central Washington State

dtoots1
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Re: jd420 pics

Post by dtoots1 » Sun May 18, 2025 5:16 pm

Welll...the good news is...she is up and running...a little cleanup in aisle 7..after last time running when we found crack in cylinder..she spewed all that black oil and crap all over her pretty yellow..so not so purty now..but she runs..

dtoots1
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Re: jd420 pics..6 volt generator mount flange

Post by dtoots1 » Tue May 27, 2025 6:53 pm

Well Guys...dag nab it....i noticed my generator was vibrating at the back end...so i went to tighten her up a bit.....oops//too much..broke the flange loose...just took that last little bit..that is the backend plate with the bolt hole.

now i do have a 12 volt generator...but am not sure that the end cover will be the same...or the shaft be same??

Does anyone have a bad generator that would have a good mount on it or do i need whole generator...mine was gone thru and redone....

HOw about you LAVOY??

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Re: jd420 pics

Post by Lavoy » Thu May 29, 2025 8:08 am

Nothing I have, only rebuilt generators.
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dtoots1
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Re: jd420 pics..re..gen cutout relay?

Post by dtoots1 » Sat May 31, 2025 8:11 am

was looking at Steiner tractor....find an item looks similar to that resistor question i asked about...they call the item a 6 volt cutout relay?,,is that something needed with the 6 volt generators?? this item mounts directly to the generator...mine was inside the dash housing...item #ABC015 at Steiner Tractor....same sceenario 1 wire in 1 out

Jim B
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Re: jd420 pics

Post by Jim B » Sat May 31, 2025 10:03 am

According to the parts book your 420 should have a 4-terminal voltage regulator, Delco Remy number 1119575. Web search that Delco Remy number and you will find pictures of it. I believe those were mounted above the battery, at least that is where the one on my 430C was.

A plain cutout was used with the three-brush generators. Your 420 should have a two-brush generator (Delco Remy 1101859) and needs a regulator. The number may be a bit different but if it has a number on it post it and I will check it out to see if it is a sub number for the original.

dtoots1
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Re: jd420 pics

Post by dtoots1 » Sat May 31, 2025 4:35 pm

Jim,

i checked on voltage regulator and generator..cant see number on v/r....nor plate on gen...however i can see into the end plate..it is the vented kind...and does have 2 brushes...not 3..at this late date i cannot find my receipt or orig pkg. voltage regulator is 4 tab

edit...i have to assume at some time it had a 3 brush gen...

Dtoots1

Jim B
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Re: jd420 pics

Post by Jim B » Sat May 31, 2025 5:27 pm

Is there a chance the generator has been changed to a 12 volt one? As Stan Mentioned a while back location makes it sound like it could be a dropping resistor. Other than that, I would remove it. You could have the generator tested to see if it works and what voltage it is to eliminate a chance of damaging your new regulator.

A cut out used with a generator would have been directly wired to one post of the generator not in series between the starter switch battery cable stud and ignition switch.

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Stan Disbrow
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Re: jd420 pics

Post by Stan Disbrow » Sun Jun 01, 2025 6:20 am

Hi,

The original 420 generator used a regulator in a box with two relays in it. One was the settable voltage regulation relay. The other was the On/Off (aka Cutout) relay that opened up when the ignition was switched off. Together, they operate the field windings inside the generator. A two-brush generator.

The earlier generator on the M sported a third brush attached to a movable strap on the outside of the generator housing. This set the charging voltage and supplied the field power back to the generator via a resistor (or not) on the ignition switch. With the resistor switched in, Lo charge was selected. With the resistor bypassed, Hi charge was selected. And then there was a cutout relay all by itself behind the dash.

The cutout relay opens up to remove power from the field coils. Otherwise, they drain the battery.

I can't recall which style the 40 had, but that doesn't really matter for this issue....

So, now that unknown part could still be a resistor or a cutout relay or an automatic circuit breaker. It all depends on what someone mucked around with over all this time. Does it sport a 2-brush gen, a 3-brush gen, or an alternator? I have seen all sorts of changes on machines as the decades march along.....

Alternators tend to use solid state regulators, but they wind up doing the same job in the end. Voltage regulation and cut-out when the machine is turned off. The main difference between a generator and an alternator is the generator has permanent magnets inside so it is self-exciting while an alternator does not - it must have a battery present to operate. And an alternator has the field coils on the rotating shaft while the generator has the armature on the rotating shaft.

One thing though, if there is an alternator then it is 99 44/100 percent likely to be 12 volts and not 6. And then 12 volts needs a dropping resistor to the ignition coil to feed it 6 volts.

Stan
There's No Such Thing As A Cheap Crawler!

Useta Have: '58 JD 420c 5-roller w/62 inside blade
Useta Have: '78 JD350C w/6310 outside blade
Useta Have: '68 JD350, '51 Terratrac GT-25
Have: 1950 M, 2005 x495, 2008 5103 (5045D), 2025 3025E

dtoots1
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Re: jd420 pics..cut out

Post by dtoots1 » Mon Jun 02, 2025 7:17 pm

Well Stan,

You the man!...What i have..had..is a 2 brush generator....which from what you have said...did have a cutout in behind the dash--which is where the thingamajig was located....so while it was running i did check the ammeter and see that it was fluctuating and even showing up on negative side while engine running....no light even on machine yet..so had me wondering if thingamajig does indeed need on it...

Now it tis a bit moot...since the long arm for front bucket dropped and caught my battery and jammed my positive post and appears to have broken post inside as setting cocked now....and seems engine starts runs a bit and quits....

So another investment in dang 6 volt battery to try again..

so explain once again where the thingamajig should be connected and which post on generator?? or voltage regulator does the blame thing run to?
???believe this is moot???

or is the cutout actually in the 4 post voltage regulator?

have 4post voltage regulator and 2 brush generator

And to answer Jims question...NO it is definitely a 6 volt generator that i had cleaned up and rebuilt at the auto electric shop...that has now closed by the way..so i cannot go there and get the mounting plate that i broke on the blamed thing.

this is weekend job

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