2355 MFWD doesn't roll

1astronautfarmer · Jul 10, 2017

Hello all,

I have a 2355 that does not roll well when the clutch pedal is depressed. The clutch is disengaging fine with no drag but when I depress the clutch to come to a stop I don't need to use the brake. There is enough drag somewhere in the system to stop me. The drag is manifesting itself / involving the left rear drive tire. Here is what I have done so far: Checked to verify that the MFWD is disengaging by following the procedure in the tech manual. Jack up left front tire, turn off MFWD, run engine at 1000 rpm and left front tire should rotate easily by hand. It did. Turn the MFWD switch on and the tire does not rotate. Jacked all 4 tires off the ground and ran the tractor in gear. I could not get the left rear wheel the rotate without engaging the right wheel brake and when I released the right brake pedal the left rear stops immediately. Thinking possibly I have a bearing failure in the left final drive I removed the left final drive and it rotates freely. Put stub shaft back into differential and it would not rotate. Pulled rockshaft cover to get a look inside. All looks great. All gears show no sign of wear. No sludge of any kind in base. Backed handbrake adjustment way off and that made no difference. Disconnected the front drive shaft and now the left stub shaft rotates freely. Hindsight being 20/20 makes me wish I had removed the driveshaft first....oh well.... Wouldn't it be great if I could start the tractor now so oil pressure could release the front MFWD clutches to see if the left wheel would rotate freely....but we can't until we reassemble it.
So I guess the question is why / how is the left rear tied into the MFWD to the point that it severely inhibits the ability of the tractor to roll? I also own a 2350 MFWD that rolls fine even with the 4 x 4 engaged or disengaged. I purposely went to the barn today and ran that tractor around in 2wd and 4wd so I could be certain of my words here. That tractor on a very very slight grade will roll off. This 2355 will not move.
I'm probably missing something easy here but I need help to see it.
In the end I will probably say to myself..."gee whiz...Ray Charles could have seen that"

Thanks everyone...Dan

jd110 · Jul 10, 2017

My guess is that the retractor pins in behind the brake piston are causing the drag. When you removed the final drive, the brakes are released and allowed the wheel to rotate. WHile the final drive is off, I would remove the brake piston and replace the orings on it. You can then access the retractor pins and I would recommend replacing them as well. You could as a test, bolt the final drive back together while front driveshaft is unhooked and see if axle turns. If it doesn't remove the final drive again and press the piston fully back into the axle housing and then reinstall the axle housing To see if axle then turns. The retractor pins are supposed to prevent brake drag, but when they malfunction, they cause the brakes to drag.

1astronautfarmer · Jul 11, 2017

I will pull the brake piston off tonight and look into the retractor pins and replace the O-rings and pins.

Tx Jim · Jul 11, 2017

jd110
Do you know the reasoning for JD engineers installing brake disk retraction springs on 55 & later utility tractors seeing that 20-50 series utility tractor brakes operated just fine without the springs? Were the springs added for better fuel economy?

1astronautfarmer · Jul 11, 2017

jd110 and Tx Jim
Got the brake piston out and found the remnants of the axle nut retainer clip in pieces and behind the piston next to the inner o-ring. Quite a little pile of metal settled there at the bottom and apparently, as jd110 said, was stopping the piston from retracting. Flushed and disassembled, cleaned and reassembled the planetaries and am a very happy camper that I found NOTHING scoured. Looks like O-rings, gaskets, retainer clip, axle bearings and seals, and a handbrake band and I will hopefully be good to go.

Dan

jd110 · Jul 11, 2017

Tx Jim said:
jd110
Do you know the reasoning for JD engineers installing brake disk retraction springs on 55 & later utility tractors seeing that 20-50 series utility tractor brakes operated just fine without the springs? Were the springs added for better fuel economy?

TxJim, you are correct that fuel economy was the reason for adding the retractor pins. They do reduce parasitic drag when operating properly. I don't like them since they do cause problems at times with the brakes drag terribly when they malfunction. They are also the root cause of the soft brake pedal on the 5E series in my opinion. With the brake piston being retracted further than in the past, the brake pedal travels further to engage the brakes. Not sure why the 55 series didn't have the soft pedal issue except maybe the retractors were redesigned to pull off brakes further on the 5E series and possibly different geometry of pedal and valve operation... I have been tempted to remove retractor pins except they are used as dowel pins that keep the pistons from rotating in the housing. Also there is the liability issue with modifying brake system from factory design.

Tx Jim · Jul 12, 2017

jd110
Thanks for reply
Jim

Tx Jim · Jul 12, 2017

Dan
Thanks for update & congratulations on your repair.
Jim

1astronautfarmer · Jul 12, 2017

Well....not repaired yet.... but ordered the parts that the dealer didn't have on the shelf this morning. Brake band and axle nut retainer. Get it together this weekend. At least there is a "relatively" inexpensive smoking gun. Could have been much worse.
I want to thank you and jd110 for the input. Always good to be able to bounce things off people that have been there.

1astronautfarmer · Jul 15, 2017

TxJim and jd110
Wanted to tell you what I have found and look for your opinions.
Having found the axle bolt retaining washer in pieces in the final drive I did some investigating. I was able to contact both previous owners(purchaser and second owner) and asked if they had ever had the left final drive repaired. To their memory neither final has ever been off.
After reassembling the final drive and before I mount it I installed the stub axle into the final drive planetary and measured from the mounting flange surface to the end of the stud shaft(using accurate means, squares and vernier calipers). Then measured from the spider pin in the differential where the axle stub shaft would bottom out to the mounting flange of the differential housing. Found this measurement to be longer than it should be to the point that the head of the axle retaining bolt would not be covered by the recess machined into the axle stub shaft and could allow the retainer washer the fall out. The flange axle bearings are seated where they belong in the axle housing and all the parts and pieces are there per tech manual and parts catalog. No shims/spacers are offered but there really aren't any places to put them anyway.
You guys ever run into this?
I am thinking I do not want to put another retainer washer in if it has the means to fall out into the planetary again. Maybe wash the threads real well and red Loctite. What do you think?