Hear and feel a knocking in the drivetrain that’s consistent with driveline rotation? it could be a broken gear tooth in the rear end.
It is more common to have a damaged tooth in the spider gears (side gears) than on the ring and pinion, although, anything is possible. If you do start getting a knocking sound in the rear end, you need to check it right away before you do more damage.
In the photo below is an example of a broken tooth in the spider gears:
If you haven’t damaged the ring or pinion gear, then this can be fixed fairly reasonably.
Your choices are:
1) Buy a new set of pinion gears and install them
2) Upgrade to a locker that replaces the side gears such as a Lock-Right.
3) Weld up the side gears to form a “Lincoln Locker” or spool type of setup.
Welding the gears should only be done by an experienced welder with experience welding up spider gears.
Jim Oaks is the founder of TheRangerStation.com, the longest-running Ford Ranger resource online since 1999. With over 25 years of hands-on experience building and modifying Ford Rangers — including magazine-featured builds like Project Transformer — Jim has become one of the most trusted authorities in the Ford Ranger off-road and enthusiast space. In 2019, he was loaned a Ranger FX4 by Ford Motor Company to test and document across the TransAmerica Trail. Jim continues to inspire and guide Ranger owners around the world.