[44gun]

have an 89 420 that the wheel on the diff lock side acts as if the diff. lock is not disengaging all the time. checked my repair manual and nothing on the diff. lock. looked underneath
and don't see a missing spring or any return type device. it is really locking up and then releases and snaps the diff. lever violent.obviously can't use it this way or will do serious damage to something expensive. anyone have any thoughts? thanks Doug

 

[knottyrope]

could have worn dogs inside the diff, wont really know until you take it apart

 

[jdmaninlouky]

I like to put it in reverse and travel a little ways to disengage it . Much like an old 4WD truck don't want to come out of lock-up low unless you do that . I just do it out of habit now on my tractors ; as my 455 , 445 and 420 all have locking diff .

Might try that and see if it helps

Dave

 

[44gun]

David, I tried that trick and it caught again going forward after 3 or 4 wheel revolutions.

KnottyRope, what am i getting into by opening the differential?

It act like the dog that's on the end of the diff arm just isn't coming out far enough so it wont catch. I was hoping my diff. lock arm might be bent or something simple. I'm learning that some things are not that simple. thanks guys. Doug

 

[coalminer16]

There is a few things. The linkage holders bolted to the frame might be a little loose and bending the tabs closer to the linkage helps. Then I have read that some have had the issue of needing to cut the pin down going into the diff on the inside to get more travel as factory travel was boarderline not enough. Then-the 4 pins locking the diff up could be worn/rounded.

What are yo ugetting into opening this up-a reseal which I advise to do anyways. Any damage found is better to find sooner then later as metal in a hydro system isn't good. But-they are build pretty tough. You likely would have more issue with the pump then the diff.