Well rear axle broke on 09 4720...

[sd455dan]

other end of roll pin
top of trans, with pinion damaged, diff side is fine though, although it seems mared up a lot on the edge, this edge sticks out just past the diff ring gear so it shouldn't impact anything... if this had to be removed, another 2ft of the trans has to be disconnected "JD says you split it in half", you need customized stands from JD with bolts that hold the tractor up then, and then you can take this out to replace it... im sure JD cost is $500 lol.

Last pic is side of screen inside, where it has to slide out, this pipe is rigid and doesnt move even once unbolted.

Wow- i have had this happen on a car gm 10 bolt rear axle before.

The only thing i could figure was that the 3 rd member (carrier assembly), some how ended up with the pinion shaft holes in the carrier were (ovaled) or not concentric.

I n other words not tight enough on the hardened shaft- allowing movement of the pinion shaft which stressed and broke the retaining pin(s).

Once this happened it was only a matter of time before destruction.

The other thing that is surprising is that John Deere didn't see fit to use the much stronger 4 pinion carrier design in this tractor. It also has the advantage of being self retained (short of breakage).

The only suggestion i can make is to scrutinize the fit of the new pinion cross shaft in your carrier, If it is not at least as tight of fit as the average engine piston pin to rod or piston fit, the retaining pin(s) may be at risk of breaking again.

Sorry if this sounds alarmist but that cross shaft fit is what may have caused the original failure. IMO and my 02 cents


Good Luck on the rest of the repair - it looks like you are well on the way to a working tractor :thumbsup:

 

[Kyle_in_Tex]

Any updates?

 

[Ken]

Ramairfreak98ss
What is the Publication number for your 4520/2720 repair Manuel ?
I have a 2008 4520 power reverser with it locked in 4 wheel drive.
J.D. dealer repairman says excess of 20 hours for 2 men each at 85 hour. Most likely to be a 75 cent roll pin either fell out or broke in shifter shaft. after clutch housing is a app.4 inch housing to be opened by separating from transmission.
So requested order of book to repair. Said $200.00 and 18 bucks shipping didn't know how long to get in.
Is this the type of book you are using.
ken

 

[oldtimer 66]

A little late on this answer but I have a 4320. I bought the CD. I think it was only like $83. Now that is coming from memory. It is a searchable PDF.I just bought the CD's last year in January 2014. The JD4320 was $75 and the Gator 825I was $70. FYI Later

 

[oldtimer 66]

He is a copy of my receipt and a copy of the face of the CD showing the price and part number for the maintenance CD for my 2006 JD 4320 compact tractor. It was $75 dollars and listed as electronic document TM2370CD. I also ordered the maintenance CD for my 2010 825I Gator at the same time . It was $70 dollars and listed as Electronic Document TM107119CD. The date is not shown but it was 1/2/2014. View attachment IMG_20150311_0001.pdfHope this helps.

 

[Ken]

He is a copy of my receipt and a copy of the face of the CD showing the price and part number for the maintenance CD for my 2006 JD 4320 compact tractor. It was $75 dollars and listed as electronic document TM2370CD. I also ordered the maintenance CD for my 2010 825I Gator at the same time . It was $70 dollars and listed as Electronic Document TM107119CD. The date is not shown but it was 1/2/2014. View attachment 416184Hope this helps.

Oldtimer66
I ordered a book from J.P. and Part # is TM2137 for the 4000 Series tractor 01 Dec.06

Took a week to receive but has all the information and pictures needed to Remove and replace any part of the 4520.
How are you doing with the 4720 Maybe not yours but Ramairfreak98ss.
Dealer mention there is several little problems with this series usually under warranty mine has to many years and hours
As soon as the weather settles here going to separate and replace a .50 c pin in shaft that engages the 4 whl. for shifter shaft. collar.
ken