420 shifting problems

General help and support for your Lindeman through 2010 John Deere crawler
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gohammergo
40C crawler
40C crawler
Posts: 13
Joined: Sun Jul 07, 2013 9:34 am

420 shifting problems

Post by gohammergo » Thu Feb 18, 2016 12:45 pm

Hi All,
It's been ages since I have posted anything here. I am having some issues with my 420 crawler.

I was dozing last fall, doing some cleanup, and I had it in 1st gear. When I tried to go into reverse it wouldn't shift out of first. Now, this is an old machine of course and the shifting has been a bit loose for awhile, but it has always shifted fine.

I inherited this from my dad, and I remember this happened to him once too. I recall that he took the top plate off of the transmission and did something with the shifter. So, I took the plate off to see if I could figure out what he did. It seems to me like the shift lever is not in the right location. So some questions:

1) I was trying to find a schematic to see where the shifter should reside. I found an online parts manual, but it doesn't show exactly where it should fit in. My guess is that the shifter should go in the notch at the top of the 1st and 4th shift fork? Does that sound right?
2) If I put it there, should I be able to move the all of the forks freely back and forth? The forks seem to be move freely in a rotational or side to side movement, but don't move front to back. Not sure how this should work.
3) Does anyone have any sort of diagram showing where the shifter should sit, or any other tips on this?

Thanks in advance, and best of days to all.

whiteclipse16
2010 crawler
2010 crawler
Posts: 622
Joined: Tue Mar 30, 2010 8:02 am
Location: Steubenville, OH

Post by whiteclipse16 » Fri Feb 19, 2016 7:18 am

I don't have a 420, but I believe they are similar to a 440 which I have.
If the 1st and 4th shift fork is engaged into either gear, then the other forks will not move. There is an interlock pin to keep it from shifting into two gears at the same time.
If you're in first gear then yes I believe the shift lever should go into the notch for the 1st and 4th shift fork.
When you say you removed the top plate, do you mean just the cover with the shift quadrants and pulled the shifter out, or you removed the entire assembly with the shift forks and everything.
If you're comfortable, I would remove the entire assembly. Then examine the transmission closely for any damage or worn bearings. Then determine what needs to move to manually shift the transmission back to neutral.
Then check your shifter assembly to make sure all forks shift freely. Put it back together and try running it through the gears.
In neutral the shifter should freely move back and forth between all the shifter fork notches.
Ben

Great Grandpa's 1960 440ICD 602 blade
Between SN's: 455,633 - 456,801
Currently Rebuilding/Restoring

gohammergo
40C crawler
40C crawler
Posts: 13
Joined: Sun Jul 07, 2013 9:34 am

Post by gohammergo » Fri Feb 19, 2016 9:00 am

Thanks for the reply Ben.

I took the entire assembly off. On mine, the cover with the quadrants is all one piece, not a separate section. With the assembly off, that is when I tried to move the forks back and forth. Maybe there is something with the interlock pin?

I checked the gears out from above, and all looks good to my eye. No signs of any metal shavings, nothing apparent wrong. I was going to try and shift the transmission manually into neutral without the cover on, but not being able to move the shift forks in the assembly, I figured that I wouldn't be able to put the assembly back on.

I did put the works back on the dozer yesterday. I'm going to fire it up today and drive it around in first a bit and see if I can't jiggle the shifter loose. I'll check out that pin too.

Thanks again, and take care, John

mathpaquet
MC crawler
MC crawler
Posts: 3
Joined: Sun Aug 28, 2016 6:50 pm
Location: Quebec, Canada

Post by mathpaquet » Mon Jan 09, 2017 6:41 pm

Did you ever fix that problem? I seem to have the same here.

mathpaquet
MC crawler
MC crawler
Posts: 3
Joined: Sun Aug 28, 2016 6:50 pm
Location: Quebec, Canada

Post by mathpaquet » Tue Jan 10, 2017 7:30 am

Did you ever fix that problem? I seem to have the same here.

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