JD 4300 hits a brick wall????

[Woody65]

I was hoping some of you more experienced tractor owners could point me in the right direction. I have a JD 4300 4wd hydro that stops dead in its tracks like you hit a brick wall. This occurs very infrequently and eventually allows me to start again. I will be driving along at different speeds/rpm and its seems like the tranny locks up. The pedal slams upward and knocks my foot off. It makes a sound as if gears are slamming together or not meshing properly. I always have the tractor in 4wd since it never sees pavement and I have hilly property. If I try to move again, the further I push down on the accelerator the closer to a stall I get. This is both in forward and reverse. Sometimes it does it for a brief moment and I continue without a missing a beat. Sometimes I am stuck for a few minutes. The hydro fluid is within range, the linkage all seems intact and not bent. Other than the above, the tractor performs excellent. I have read other threads which describe having a 4wd problem if the tires are not a stock size which causes the tranny to bind. I bought the tractor used and was under the impression that the tires and rims were stock. Any suggestions would help. Thanks...

 

[George2615]

Here's the choices of tires that should be on your 4300 according to Tractordata.
If yours are different it could be the problem.
If possible, try driving it in 2WD and see if the same thing happens.


John Deere 4300 Tires:
Ag front: 5.00-15 (2WD)

7.00-14 (4WD)

Ag rear: 11.2-24

Ag front: 7.00-16 (4WD)

Lawn/turf front: 25-10.50LLx15

27x8.5-15

7.00-14 (4WD)

Lawn/turf rear: 41LLx18.00-16

11.2-24

41x14.00-20

Industrial front: 25x8.50-14

Industrial rear: 15.00-19.5

 

[Woody65]

Thanks for the info. I have turf tires front and rear. I will check the size when I get to the property next week.

It happens so infrequently that I would have to drive it around for days to see if it occurred in 2wd.

 

[9973720wb19]

Woody65. I have Standard R4 tires and rims off my 4720 Cab they have about 150 hrs on them - let me know if you're interested in them. I switched to R1s for snow and mud reasons. I don't know how I'd get them to NY from MD though.

 

[kennyd]

I would jack up the front end, and inspect the front axle carefully for gear noise, backlash, and general condition of the fluid. The MFWD is not meant to be used full time so I suspect there might be damage in there somewhere.

 

[kennyd]

Woody65. I have Standard R4 tires and rims off my 4720 Cab they have about 150 hrs on them - let me know if you're interested in them. I switched to R1s for snow and mud reasons. I don't know how I'd get them to NY from MD though.

Your 4720 wheels would be to large for his 4300.

 

[Woody65]

I would jack up the front end, and inspect the front axle carefully for gear noise, backlash, and general condition of the fluid. The MFWD is not meant to be used full time so I suspect there might be damage in there somewhere.

Kennyd, I will take a look at the axle and the fluid. I know that it is full, cause I checked it last week. Maybe I will just drain and refill with new fluid.

In regarrds to the MFWD, I thought that it was ok to leave in 4wd. I have read that other members have done it without any problems. Not to say that that makes it ok.

 

[beenthere]

Is the "stop dead in its tracks" the same or very similar to when you are travelling and simply remove your foot from the pedal ?? As the 4300 does stop pretty quick when doing that.

Or is it more like locking up and not the same?

Sounds to me like a linkage adjustment, but may be the 4wd is just winding up so tight (as it can do that on dry ground, similar to being on pavement. Wet ground is different and will give some slippage).

Run it in 2wd and see if it will do the same "stop dead". The mystery to me is the comment that it throws your foot off the forward pedal when it slams up. That is harder to understand unless something is caught in the pedal linkage.

Let us know what you learn as you try things out again.

 

[5030]

4WD is really Front wheel assist and should not be engaged all the time. Everythime you corner, there is a lot of internal strain on the front end components. Sounds to me like sonething went south in the front end.

I rarely use FWA except when I need it.

 

[Woody65]

Is the "stop dead in its tracks" the same or very similar to when you are travelling and simply remove your foot from the pedal ?? As the 4300 does stop pretty quick when doing that.

Or is it more like locking up and not the same?

Sounds to me like a linkage adjustment, but may be the 4wd is just winding up so tight (as it can do that on dry ground, similar to being on pavement. Wet ground is different and will give some slippage).

Run it in 2wd and see if it will do the same "stop dead". The mystery to me is the comment that it throws your foot off the forward pedal when it slams up. That is harder to understand unless something is caught in the pedal linkage.

Let us know what you learn as you try things out again.

It has thrown me out of my seat if I am traveling at any rate of speed

The foot pedal punches me in the bottom of my foot.

Since you mentioned linkage it got me thinking. I have been having a little trouble changing gears. It hangs up and wont smoothly change from A to B to C or N. I don't know if this would cause this too happen.

 

[9973720wb19]

Your 4720 wheels would be to large for his 4300.

Oh, Okay...thanks.

 

[RoyJackson]

Woody65. I have Standard R4 tires and rims off my 4720 Cab they have about 150 hrs on them - let me know if you're interested in them. I switched to R1s for snow and mud reasons. I don't know how I'd get them to NY from MD though.

The rims won't fit...the 4300 has 6 bolt rims, the 4720 has 8 bolt rims.

 

[Egon]

As mentioned, put it up on blocks, all four wheels, and run it at lower rpm's. Look and listen, check all the linkages and change ranges. Might want to activate the steering and pto's also.

Note: not experienced

 

[jenkinsph]

I agree with Kenny and others that your front axle and or drive shaft is the likely culprit. If the front axle locks up I don't think it will matter whether you are in 4x4 or 4x2 as the front drive line components are all turning full time and the disconnect is at the middle of the tractor. On a highway vehicle the front hubs are either locked or unlocked but not so on a mfwd tractor.

Don't know for a fact but suspect you will need to rebuild the front axle.

 

[Rick Gent]

I would agree with the others that if the tire size is correct, it's a problem with the axle getting bound up due to no wheel slippage. If your running on hard dry ground it's the same as pavement. The sharper you turn in 4wd, the more wheel slippage you need to keep the axle and everything behind it from binding up. I would suggest using 2wd most of the time and only use 4wd when you really need it. I leave my 4wd engaged all winter to plow my driveway, but in the winter there's always SLIPPAGE!!!

 

[Gary Fowler]

I would immediately consult your dealer on this before the problem causes some other item to be damaged.

I don't believe your use of full time 4 WD while on pasture or dirt would damage the running gear and as you say you are in constant hilly terrain which could be unsafe if not in 4 WD. It might cause some premature wear and for sure wears the front tires faster but it shouldn't cause your transmission to lock up. I think there is more likely a problem in the HST transmission. Damaged gears in the front axle wouldn't cause your HST pedal to jump back up and lock up the tractor.

 

[Woody65]

Thanks for all of the suggestions. I will take a look and a listen to the front axle and drivetrain to see if anything is damaged. Also, I am going to try and drive it in 2wd as much as I can to see if it occurs while the 4wd is disengaged. If anything comes out of it I will let you guys know.

 

[Woody65]

I would immediately consult your dealer on this before the problem causes some other item to be damaged. I don't believe your use of full time 4 WD while on pasture or dirt would damage the running gear and as you say you are in constant hilly terrain which could be unsafe if not in 4 WD. It might cause some premature wear and for sure wears the front tires faster but it shouldn't cause your transmission to lock up. I think there is more likely a problem in the HST transmission. Damaged gears in the front axle wouldn't cause your HST pedal to jump back up and lock up the tractor.

Gary,
I was under the same impression that driving in 4wd on dirt or pasture ( which is what I am always driving on) would not cause any damage to the drivetrain.

I hope you are wrong about the transmission but I will look into it as you suggested. Thanks

 

[jd110]

I would recommend draining the oil in front axle and transmission. Remove the sump screen and check for any debris in the oil and/or screen. Use a long flexible magnet to probe into the transmission and axle to see if there are any loose pieces. It sounds to me as if there is possibly a broken tooth floating around in the system ad occasionally getting caught between two gears or between a gear and the housing. If so, you are in a real danger of having a catastrophic failure. If no loose parts are found floating around I am not sure what is going on. Keep us posted on what you figure out.

 

[Agvg]

Loosing oil pressure in the transmission might be an issue, the behavior of the pedal excludes front axle faults by my logic, suppose you have a test outlet so it might be an idea to put a manometer there and have it so you can read it under normal use, to see variations and see what goes on when it have the problem.