new steering gear getting chewed up

[bigjake]

I replaced the steering sector gear and steering pinion gear on my JD LA140 because the old gears were chewed up and the steering wasn't working properly. I used genuine JD parts. After only one cut the new gears are starting to get chewed up. I assume it is because the steering gear rocks up and down as the steering wheel is turned? I replaced parts 20, 21, 23, 24, 25 in the attached diagrams. I tried to insert a video but got an error that it was too big so inserted screenshots showing the gear rocks up and down. Both bolts 23 and 25 are as tight as they will go but there is a fair amount of play. I assume there has to be play to allow the sector gear to rotate but it seems to allow the gear to rock up and down about a 1/2" too which I assume is causing the gears to get chewed up. What am I missing?

 

[Rivets]

I’m will to bet your problem is a worn steering shaft bushing, part #14 on your diagram. Anytime I service a steering problem like yours that is one of the first parts I look at. A worn bushing will allow too much play between the sector gear and pinion gear.

 

[bigjake]

I’m will to bet your problem is a worn steering shaft bushing, part #14 on your diagram. Anytime I service a steering problem like yours that is one of the first parts I look at. A worn bushing will allow too much play between the sector gear and pinion gear.

i didn't replace the bushing but there doesn't seem to be any play at all in the pinion gear. The problem seems to be excessive play in the sector gear. Where it connects to the linkage to the wheels, it moves up and down about 1/2" so the gears are meshing at an angle and getting chewed up. Should the sector gear rock up and down like that? should I shim it with a washer or something?

 

[Rivets]

Are you sure bushing number 24 is not costed?

 

[Rivets]

From your pics something is not assembled properly.

 

[bigjake]

Are you sure bushing number 24 is not costed?

that's a brand new bolt and bushing

 

[bigjake]

got me wondering if bolt #22 didnt go thru cleanly and the gear is hung up on the shoulder of the bolt. I'll check that tomorrow.

 

[StarTech]

IF you didn't replaced #14 it is probably badly worn.

 

[bertsmobile1]

IF you didn't replaced #14 it is probably badly worn.

And from memory there are 2 of them
After that there is the problem of the steering pins in the front cross member , have they been greased ?
And of course the bushes in the wheels themselves
Wear in any or all of them puts excessive load on the fan gear
Replacing the fan gear & bushes is one of those 5 hands jobs
Finally did you lubricate the fan gear & pinion ?
Mine always get a good shot of dry Lithium Chassis grease ( CRC Product )
What I see is paint transfer from the fan gear to the pinion

 

[Biggs]

I'm experiencing the exact thing on an LA145. I just bought a steering repair kit from my local dealer, though once I got home with it I noticed the label on the kit is Atlantic Quality Parts, not John Deere, so I'm a little aggravated about that (it was placed label-down on the counter, so I didn't notice or even consider the dealer would have been selling anything other than genuine parts). My sector gear rocks up and down as well (just at the sides) but I think it has to for the steering linkages to be able to move up and down with the way the front axles can tilt.

I just mowed for the second time since the repair, so the parts have about 1.5 hours on them, the steering is tighter and more difficult to deal with than the (assuming) original gears I just replaced with 210 hours on them.

My mom has the same mower with around 260 hours - I just mowed at her house today and her steering is significantly lighter than I recall mine being.