7410

[Tractorboy88]

Pulled transfer case off and apart today to see why the MFWD was permanently engaged on a 7410 PowerQuad. Found the sealing rings on the shaft were missing along with worn bushings. New bushings and all seals on the way from Deere.

I decided to check and clean the suction screen while i was there. Pulled the screen, not to bad, except for a bent up little spring hung up in the mesh of the screen. Felt around in the valley under the screen with my finger and dug out a couple of big chunks of, what i believe is, plastic, along with a little dimple piece.


Penny for scale.

Im guessing this is either part of a sensor or switch that is broken off, but which one would it be?

I checked the PTO speed sensor and the 3 switches i could see on the front of the trans around the filter, but none were broken. I would think if it were a speed sensor, it would not have a spring, as those are magnetic/hall effect sensors. Could it be some sort of neutral safety switch or pressure switch?

 

[MORRISONSTEEL]

I think that might be parts out of the air pump valve on transmission charge pump. Search re47291 in the 7410 parts catalog for an image.

 

[MORRISONSTEEL]

View attachment 7410.pdf

 

[jd110]

I think that might be parts out of the air pump valve on transmission charge pump. Search re47291 in the 7410 parts catalog for an image.

I believe you are right. I looked at those parts when the op posted it and couldn't figure out where I had seen them before. Nice catch! The original poster will need to pull the front cover from his transmission to replace that unless it is leftover from a previous failure.

 

[Tractorboy88]

Thanks for the replies.

Fixed the mfwd with the seals.

The hydraulic pressures are low. 200 cold, 100 hot. Directional shifts are delayed, third arms pick up slow, chattering, and unevenly, steering moans when turning. I was thinking that the air pump was burned up from the mfwd leak. I've got the operation and tests manual, but have been too busy to get back on the 7410.

 

[Tx Jim]

Thanks for the replies.

I was thinking that the air pump was burned up from the mfwd leak.

JD is very proud of the charge pump if kit that's listed doesn't correct pressure problem. Pump listed is dependent on tractor serial number.
RE259870 Pump Kit - KIT, MW POWER QUAD PUMP & PRV ADD 1,201.74 USD

 

[Tractorboy88]

JD is very proud of the charge pump if kit that's listed doesn't correct pressure problem. Pump listed is dependent on tractor serial number.
RE259870 Pump Kit - KIT, MW POWER QUAD PUMP & PRV ADD 1,201.74 USD

Tx, can you clarify that a little better for me?

I'm gonna try another gauge tomorrow, but it wouldn't reach but about 5 psi lube pressure today at WOT.

 

[Tx Jim]

What do you need me to clarify? Tractor serial number is required to pin point pump kit.

 

[Tractorboy88]

What do you need me to clarify? Tractor serial number is required to pin point pump kit.

I misread what you posted, sorry Tx.

My nearest JD with that kit in stock is about an 1.5 away. Kit is ~$40. Looks like i'll be making a road trip today.

Deere must have a problem with these if they put together a kit?

 

[beenthere]

Tb88
One customer will ask why don't they put everything needed in a kit, and the next will assume the kit is indicative of a problem.
Don't think JD can win either way..

 

[jd110]

The transmission pump problem should not have an effect on high pressure hydraulic functions. They are totally different system, sharing only the oil. Only possible connection is if the transmission pump is aerating the oil to the point of causing the Hydraulic charge pump and high pressure pump to cavitate... Although on second thought, the air pump in the transmission pump does keep oil levels in transmission housings correct during operation by pressurizing housings. Possibly could be getting low oil level around sump screen during operation causing cavitation. I have never had an air pump fail to see the results of a non functioning one.

 

[Tractorboy88]

The transmission pump problem should not have an effect on high pressure hydraulic functions. They are totally different system, sharing only the oil. Only possible connection is if the transmission pump is aerating the oil to the point of causing the Hydraulic charge pump and high pressure pump to cavitate... Although on second thought, the air pump in the transmission pump does keep oil levels in transmission housings correct during operation by pressurizing housings. Possibly could be getting low oil level around sump screen during operation causing cavitation. I have never had an air pump fail to see the results of a non functioning one.

This is what i'm now convinced is going on, the pump is not transferring fluid back.

 

[Tractorboy88]

Got the pump repair kit yesterday.



Looks like it to me!

 

[Tractorboy88]

Well after removing the front cover, the air pump portion of the pump was indeed broken apart, the few last pieces were held in by a broken spring.

I replaced the air pump assembly and all gaskets and changed the filter once more.

The transmission pressure warning comes on briefly as the tractor starts up. My lube pressure stays at 0 at idle, spikes to 15 at 1000rpm and stabilizes to 10psi. It starts slowly dropping as the tractor runs longer till I have none at wide open throttle.

Maybe I should of changed the entire pump assembly.

 

[jd110]

If you do take it ack apart, be sure to look at the aluminum housing where the pump gears rotate against. If the pump is worn, chances are good that the aluminum housing is worn also.