This probably wont solve your problem but it may provide some insight. May be more than just a switch issue....
https://forum.ih8mud.com/threads/reverse-indicator-issue.944324/
The lock on type are too big to fit into that gap. You have to use a standard size on your grease gun, and they are still a tight fit and have to be aligned precisely in order to stay attached to the grease zerk.
Could it be the computer opening the throttle plate wide open to correct for some mixture abnormality?
I believe that would produce the sound you are hearing.
The speed sensor and splines are two completely different issues.
To remove the rusted in speed sensor the hub has to be removed and the sensor then pounded out from the inside. The spline condition will be observable during hub removal.
I did the 10% underdrive on my 2002 and it made all the difference in the world driving in mountains, in the east anyway. RPM`s increased by only 400 and no change in fuel milage. My loaded weight is 7600 lbs.
Now I can make it up about 3/4 of the grades without a downshift. It will still kick...
Check your front axle splines and drive flanges. Sounds like one or both axles splines are stripped.
Spinning axle splines would produce the sounds you are hearing and trigger the lights you are seeing.
Correct, they are studs that are screwed in. You should be able to remove the old ones from the old hub by locking two nuts together on the studs and wrenching them loose with the wrench on the inner one.
How about this one. Looks like it has the 2 slot openings.
https://www.ebay.com/itm/356278543752?chn=ps&mkevt=1&mkcid=28&google_free_listing_action=view_item&srsltid=AfmBOorpjWJQR-egAdTM3RTJQBR_gyOaP20DzM9QynjQOS2YgZzyO034PvA&com_cvv=8fb3d522dc163aeadb66e08cd7450cbbdddc64c6cf2e8891f6d48747c6d56d2c
I did cut mine but I installed the 2003+ version arb on my 2002. Maybe the older version didn't require it the cutting? Different mounting system perhaps?