John Deere 4120 Questions

[RoyJackson]

I cant find anything in my 4120 manual about adjusting the clutch.

Yeah...noticed that later when I looked at the operator's manual. That kind of sucks.


Well, head to your local Deere dealer and either ask for the instructions (out of the service manual) or spend the 30-60 buck and buy the manual on CD-ROM.

 

[Riverrat]

Any thoughts on the e hydro version. Compared to the power reverser.

 

[sunnyside360]

I cant find anything in my 4120 manual about adjusting the clutch.

Some other tractor manufacturers who make hydraulic type clutches also do not specify how to adjust the clutch. Can't imagine why not. But, their service manual does state how to adjust the clutch. The JD shop guys may tell you how to do it.

 

[sunnyside360]

..............
2) The brakes have about 1/2 to 3/4 ' inch of travel before fully engaging and you have to stand on them pretty hard to stop/keep the tractor stopped. There seems to be no gradual it is all or nothing. Again i am used to the hydraulic brakes of the larger tractors not the mechanical brakes of the 4120.

My 4320 brakes require a fair amount of push to work so maybe it's normal. Also, it is possible the previous owner ran your 4120 with the brakes in the locked position like my son-in-law does occasionally --- not good for the brakes.

 

[sw14976]

When does the "tier IV" emissions kick in for the 4120, as opposed to the interim tier IV? I am a little concerned with the new technology with tier IV (i.e. clogging particulate filters and such). I noticed that John Deere is putting Yanmars in the new 4 series tractors coming out this spring. Any comments?

 

[Tx Jim]

Some other tractor manufacturers who make hydraulic type clutches also do not specify how to adjust the clutch. Can't imagine why not. But, their service manual does state how to adjust the clutch. The JD shop guys may tell you how to do it.

Most true hyd clutches are controlled by a "hyd valve" so there's no clutch pedal adjustment(free travel) that can be performed. Without the aid of a tech manual I think clutch pedal rod attaches to parts key #52 on a PRT trans which controls clutch valve(parts key #35)

 

[arlen4720]

When does the "tier IV" emissions kick in for the 4120, as opposed to the interim tier IV? I am a little concerned with the new technology with tier IV (i.e. clogging particulate filters and such). I noticed that John Deere is putting Yanmars in the new 4 series tractors coming out this spring. Any comments?

I think tier 4 has kicked in. As you said the new 4 series is coming out now. Tier 4 is the reason they have Yanmar engines in them. JD is focusing on 75HP and up, and getting smaller engines from Yanmar. They are puting Yanmars in their skidloaders too. I'm sure that they are great engines, but I hate to see the JD powertech engines go.

 

[sunnyside360]

....... I hate to see the JD powertech engines go.

Ditto on that. But, the Yanmar engine in my 2007 3720 has been trouble free . The JD Powertech engine in my 4320 has been excellent also. Darn tier 4 .........

 

[sw14976]

I'm leaning towards the 4120 to get the JD engine. I grew up using a 4020, and really loved to hear that big inline six growl.
All of the specs except HP are the same for this series. Does JD just use more boost, and different injectors?

 

[arlen4720]

I'm leaning towards the 4120 to get the JD engine. I grew up using a 4020, and really loved to hear that big inline six growl.
All of the specs except HP are the same for this series. Does JD just use more boost, and different injectors?

Yes, more boost, and the 4520 and 4720 have a totally different injection system than the 4120 and 4320. Both types use unitary injection pumps. So there is a separate pump/injector for each cylinder. The pumps are driven from extra lobes on the camshaft. The 4520 and 4720 have an electronically controlled engine so the injection system is simpler mechanically, and leads to the eThrottle feature which is not available on the 4120 or 4320.
Take a look at the parts breakdown from JD parts, you can see the reduced component count.
The Powetech engine has been a fantastic engine for JD.