L4200 front axle differential

David14d

New member

Equipment
Kubota L4200
Jun 1, 2019
2
0
0
Coalville
Hi I am having a problem understanding how to set the preload on the input pinion shaft.

Manual basically says replace bearings and spacers as they were, then refers to tightening the locknut.

Locknut torque is set at 72 - 86 lbft, it then says install pinion in case and wrap a string round the shaft and pull with spring balance.( should be a force of 22 - 26.5 lbs)

To calculate force multiply the radius (from centre of shaft to string) by the reading on spring balance. ? What should i measure in inches, mm,cm

Then after all that it says if you cant get the factory spec adjust with the locknut? So do you just loosen the locknut? Very confusing. Thanks in advance for any assistance.
 

Pau7220

Well-known member

Equipment
L3650 GST, Landpride TL250 FEL w/ Piranha, 6' King Kutter, GM1084R Finish
Aug 1, 2017
785
276
63
Scranton, PA
I can only speak from the automotive / truck side. Every pinion I've ever set up was done only by feel. Every mechanic I know does it the same way.
Tighten the nut until you get zero bearing play... from that point, tighten the nut until a SLIGHT amount of resistance is felt while turning the pinion.
Overtightening will damage the bearings, undertightening will allow the ring gear to push the pinion away causing gear wear. Use your head and you'll be fine.

There's also the in/lb torque wrench method which there are tons of YouTube videos on if you don't feel comfortable enough.
 
Last edited:

David14d

New member

Equipment
Kubota L4200
Jun 1, 2019
2
0
0
Coalville
Thanks, thats what i am doing, tried going to local dealer but so far all they have done is direct me to the manual.

I think if I go by feel it should be good, but that said if I can work out what the manual actually means I would rather do it to the book.
 

thad.gray

New member

Equipment
Kubota L4200
May 10, 2019
2
0
1
Fayetteville, TN
I am doing the exact same as you are now. This is the second set of gears I have installed in the past year. Got a quest how much of the pinion overlaps onto the ring gear. The attached picture is my broke ring gear.
 

Attachments