Last Generation 4x20 Series Reported Problems

[Cahaba Valley Farm]

I had a phone call with a older gentleman yesterday that told me he has a JD 4720 that has had the front axle seals replaced like 12 times. I was almost in disbelief when I heard it but I decided to do some digging and I found this thread here: https://www.tractorbynet.com/forums...erating/360689-new-2015-john-deere-4052r.html which the guy stated that his 4320 ate up front axle seals. I spent over seven hours this morning combing through this section of the site and I have found the last generation 4x20 series Deeres, especially the 4720 seemed to have quite a few issues with axle leaks, PTO problems, fuel gauge issues and steering lockup. None of this seems to be occurring with the current 4 series lineup. Am I wrong?

 

[beenthere]

Which model of JD do you have?

 

[Cahaba Valley Farm]

Which model of JD do you have?

None yet

 

[beenthere]

Which seal in the front axle seems to be the problem?

This may not be a seal problem, but an oil-leaking problem around that seal.
If the axle housing is not vented (I leave the fill/dip stick plug loose), then when the axle oil heats up, it will push out around the seal. Had that problem once, and cured it with the loose plug.
Others have modified the plug to become a vent. Recall the thread, but cannot find it at the moment.

 

[Cahaba Valley Farm]

Which seal in the front axle seems to be the problem?

This may not be a seal problem, but an oil-leaking problem around that seal.
If the axle housing is not vented (I leave the fill/dip stick plug loose), then when the axle oil heats up, it will push out around the seal. Had that problem once, and cured it with the loose plug.
Others have modified the plug to become a vent. Recall the thread, but cannot find it at the moment.

Thanks for the suggestion beenthere. I remember several people mentioning that when I was reading the threads yesterday. I will email him to find out and let you know.

 

[Cahaba Valley Farm]

Others have modified the plug to become a vent. Recall the thread, but cannot find it at the moment.

Is this the thread you are thinking of?
https://www.tractorbynet.com/forums...ing/168295-does-everyone-have-front-axle.html

 

[Cahaba Valley Farm]

For the sake of the discussion here is a article that I found that suggests Deere fixed the leaking front axle seals on the current generation 4 series:
214 John Deere Ride & Drive | Tractor News

If any of you have information or experience that contradicts this please share.

 

[dsb5610]

I have a 2013 4720 with over 1400 hours. I have not had any of the problems you listed. The only issues I recall were the squeaky steering wheel, which requires the steering wheel to be removed to lubricate, and a wire coming lose on the air seat pump, which required the seat pan to be removed. I fixed both issues myself and I do all the maintenance per the recommended schedule.

dsb

 

[Cahaba Valley Farm]

I have a 2013 4720 with over 1400 hours. I have not had any of the problems you listed. The only issues I recall were the squeaky steering wheel, which requires the steering wheel to be removed to lubricate, and a wire coming lose on the air seat pump, which required the seat pan to be removed. I fixed both issues myself and I do all the maintenance per the recommended schedule.

dsb

Interesting :scratchchin: So maybe it is a set of problems that is confined to a particular range of serial numbers or years?

 

[johncanfield]

My 4720 is a 2010 vintage, I bought it with about 350 hours on the clock and have put 300 more hours on it with no seal issues. I bought a new Kubota L3900 many years ago and at 100 hours a front seal started leaking.

 

[kennyd]

Most people only register/post to forums when they have issues, you don't see threads like "I have 680 hours on my 4720 and my axles seals are NOT leaking". The data on the forums only represent a very small number of owners of these machines.

Generally, if a particular machine has constant front seals leaking, you have to look at usage like heavy FEL use without the proper REAR ballast or other external issues.

 

[oldtimer 66]

What seals are we talking about? The outer wheel seals (knuckle) or the pinion seal. I have 1900 plus hours on my 4320 and no wheel seal problems. When it was new under 100 hrs. the pinion seal started to leak. The dealer replaced the pinion seal and I have not have a problem since. It took the dealer about 10 days to fix but that was because he needed a thin wall deep 1.62 socket.