New 3120 lacks power, any thoughts?

[Deere Man]

All,
Traded my 4200 in this weekend for an eight month old 3120 with 100 hours on it. Love the way the 3120 handles, the creature comforts etc. One big problem though. Whn I go do the road and fully depress the hydro pedal the RPMs drop off drastically once I get up beyond 10MPH. I'm talking they go from 3,000 to as low as 1,500 if I don't let off the pedal. I took it back to the dealer and they replaced a kinked fuel line ane ran it on the dyno where it was putting out 24 hp at the PTO. I bring the unit back home and still have the exact same problem. I also notice it in "b" range when mowing if I go up a slight grade or work the hydraulics. My gut tells me it is a hydraulic or hydrostatic problem, perhaps a restricted line or filter. I think the dealer feels I should just live with this but I know it's not right, if the manula says it should go 18mph it should do it and it should not bog down like that. What are your thoughts / experience with this unit?

As a side note I called the previous owner and he traded it in because of this problem. He took it in twice for repair and never got anywhere and got fed up.

Thanks for the input.
Scott

 

[johndeere_2210]

I would suggest going back to the dealer and asking him/her to come out to your home and "see" the problem first hand/experience it and in the best case senario, they bring a 3120 with them and try them side-by-side and validate it's the machine or just the way it is.

 

[orlo]

DeerMan:

I have a 3320 (Just a tad more HP) and if I'm in C range and don't have load match on and drop the hydro pedal the same thing happens. It will accellerate but the RPM's drop a lot (as you say, from full open to maybe 1500) then it slowly accellerates. If I either slowly depress it or put load match on it will accellerate much faster and keep the RPM's up. I've done maybe 14mph in my back yard without bouncing off the tractor so it would easily do 17 on pavement. But the E-Hydro is touchy and it's very difficult to modulate 'just a little more' on it. I actually prefer the mechanical hydro on my 2305 much better. I find it's very tough to depress the E-Hydro pedal 'slowly'.

It will also happen to me in B range if I'm mowing (72" deck) in heavy grass uphiill and don't let up on the hydro. Again, load match helps here also.

Everything is probably fine you probably just need to get used to the E-Hydro (I'm still not) or take advantage of the LoadMatch feature. LoadMatch isn't just for loading. It basically keeps the engine RPM from dropping by reducing the hydro pedal setting to keep RPM's up.

Just as reference, the same thing happens on my 2305 but the 'feel' and modulation of the pedals on the mechanical hydro are so much better then the E-Hydro that it never bothers me as it seems natural to back off the hydro pedals and on the 2305 I never 'overpress' the hydro pedal due to feedback.

 

[thebigc]

I have a 3120 with the 300CX and a Woods BH and when I travel on the road, I use "C" range as well. If I set the throttle at about 2400RPM and push the pedal all the way down, she'll drop down to about 1500RPM and slowly climb back up as I attain cruising speed. I never saw it as a problem, however.

Donny

 

[Deere Man]

I guess the prob;em is that mine never recovers, it will actually continue to drop RPM's if I hold her down. The load match button doesn't seem to make a difference.

My 4200 I could hold to the floor and it would go down the road no problems.

 

[matthew3120]

I guess the prob;em is that mine never recovers, it will actually continue to drop RPM's if I hold her down. The load match button doesn't seem to make a difference.

My 4200 I could hold to the floor and it would go down the road no problems.

Sorry to here that I have a John Deere 3120 and an max it out at 19.6mph without it stalling out.Where I live is in town and most of the time I can keep up with traffic.I would take it back to the dealer.they usally are a little power house.

 

[Deere Man]

All,
The tractor went back to the dealer yesterday. I just couldn't beleive that JD would build something that would run like that. I've had 4 other JD CUT's with hydro tranny and none of them acted like that. The dealer found a new tech bulletin that said that JD was having a lot of problems with the transmission solenoids not opening all the way up and bogging down the engines. I will let you know if they get it fixed.

I also don't beleive you should have to have load match on to go down the road. The manual says that load match is for times when the tractor is under extreme load.

 

[orlo]

I agree you shouldn't need load match on but you can still use it. I use it to overcome the 'hypersensitivity' of the pedals. If I didn't use it every bump I hit I'd bounce on the seat and nail down the pedal to the floor.

The real problem I have is with the too high bouncy seat but I haven't limited the high stop yet.

 

[Deere Man]

I thought I would update everyone since it has been a while. I took the tractor back to the dealer I bought it from. instead of fixing it they turned the injection pump up but won't admit to it (you can see where they painted over the screws). I ran the thing two hours and literally used half a tank of diesel. So I took the tractor to a dealer that was farther away but has a better service reputation. Come to find out the injection pump was two teeth out of time from the factory and it had been turned up to 30HP by the original dealer. So now I am wondering if this combination could have done damage to the engine? I also don't understand how it could make 30hp at the PTO and not have any "power". Is this the difference between HP and torque? The dealer is supposed to resolve the timing issue today hopefully that will fix what I percieved as hydro problems. I just don't know whether to push the issue with deere or not since it owuld seem to me it could have been damaged. Also thought I'd let you guys know what they found, it wasn't the first one they had like that.

 

[ArkLaTexSam]

Here is my thought as I had a similar problem but the cause of my effect was not the same as yours.

My 4300 HST ran excellent for 5 years. I mostly ran it in low(A) range. Then one day I needed to go on the road so I shifted into High(C) range and the tractor would barely go. It would usually start off semi-normal and then the rpms would aggressively decline. Same thing would occur in mid-range but not as aggressive. The mechanics at my dealer said I was having major HST problems. I decided to check things over myself during the weekend.

To make a long story short I discovered that both of the brake springs under the rear axle had come off. This caused both brakes to have too much tension (brakes not releasing) which dragged the rpms down. I was a non-believer about this being the cause of my problem until I replaced the springs. It made all the difference in the world and from then on my tractor ran better than ever. It might be worth while if u check those springs if your tractor is has/had them.

ArkLaTexSam

 

[Claybuster]

My 3520 had the same problem exactly. There seemed to be a difference between the demo and the tractor I bought. I asked the dealer about the adjustment of the hydro pressure to increase the breakout force after finding some info on TBN, he said that there was an adjustment and would check into it. He called last week with a tech update from JD and picked it up on Wed. I should have it back Fri. I am curious to see the difference.

 

[Deere Man]

Claybuster I was curious if you ever found anything out. I've gone to two different dealers and I just don't think they care.

One thing I noticed this weekend. On the 4200 I use to jack it up one rear wheel at a time, put the tranny in neutral and turn the wheels to see how the brakes were adjusted up. I could turn the wheels fairly easily when the tranny was in neutral. On the 3120 it's difficult at best to turn them. Is there something different on this vs. the 4200?

I also changed the hydro filter this weekend even though it only has 170 hours on it. The drain plug magnet had a marble-sized ball of metal shavings on it and the filter has several chips stuck around the outside. There were also several fibers in the oil that looked like clutch or brake linings for lack of a better way to describe it. I was told this is normal and nothing to worry about.

I'm tired of feeling like I have to trade to "orange" to fix the problem. Any help would be appreciated.

 

[DrainPondDesign]

Just a thought but the JD 3320 engine develops maximum torque at about 1,500rpms so it may make sense for it to drop to that speed when the load increases like starting up a hill. I too was concerned about slow performance especially when blowing snow going uphill untill someone posted how much work was being done by only 30hp. Now I relax & enjoy the ride.

 

[jd110]

If your rear wheels don't turn freely when in neutral, you definitely have brake drag issues. How much "free travel" do you have on your pedals? You should have 2 - 2 1/2" of free travel before brakes start to engage. There is a turnbuckle under each side of platform to adjust left and right pedals. The debris you are seeing in the oil sounds like it may be the normal "break-in" filings. Even if the brakes have been dragging since new, chances are that they are OK. The wet style brakes used on these tractors are amazingly resistant to this kind of abuse. I have seen some larger tractors have brakes drag so bad that the wiring harnesses melt anywhere they touch the housings, and if you disassemble them, the brakes still look new. Did the oil smell burnt? If so, then I would recommend changing the fluid if you haven't yet. If your tractor is still in waranty, your dealer should be responsible for these repairs.

 

[Deere Man]

There is about 1-1/2" of travel before the pedal starts to engage. Is that the only adjustment on these brakes? I called and asked the dealer if he would adjust them and I was told that he wouldn't. If anyone has the section out of the service manual on adjusting the brakes that they could get me I would appreciate it.

 

[Nuru]

Here is my thought as I had a similar problem but the cause of my effect was not the same as yours.

My 4300 HST ran excellent for 5 years. I mostly ran it in low(A) range. Then one day I needed to go on the road so I shifted into High(C) range and the tractor would barely go. It would usually start off semi-normal and then the rpms would aggressively decline. Same thing would occur in mid-range but not as aggressive. The mechanics at my dealer said I was having major HST problems. I decided to check things over myself during the weekend.

To make a long story short I discovered that both of the brake springs under the rear axle had come off. This caused both brakes to have too much tension (brakes not releasing) which dragged the rpms down. I was a non-believer about this being the cause of my problem until I replaced the springs. It made all the difference in the world and from then on my tractor ran better than ever. It might be worth while if u check those springs if your tractor is has/had them.

ArkLaTexSam

Gee this is an excellent "out of the box thinking based on real experience" post