How do you grease the front bearings on a 1991 S-10?

You can't grease the front wheel bearings on a 1991 S-10 (or most modern vehicles) in the same way you might grease older vehicles with grease zerks. 1991 S-10s use sealed wheel bearings. This means they're packed with grease at the factory and are designed not to require further lubrication throughout their lifespan.

Attempting to force grease into them will likely damage the seals, leading to contamination and premature bearing failure. Instead of greasing, the bearings themselves need to be replaced if they fail. This is a more involved process requiring specialized tools and knowledge.

If you suspect a problem with your front wheel bearings (noise, rough turning, etc.), here's what you should do:

1. Have it inspected by a professional mechanic: They can diagnose the issue accurately. It's crucial to identify the problem before attempting any repairs. A bad bearing might sound like other suspension or drivetrain problems.

2. Do not attempt to disassemble the wheel hub yourself unless you have the proper experience and tools: This is a complex job, and doing it incorrectly can lead to further damage or injury.

In short, don't try to grease them; get them inspected and replaced if necessary by a qualified mechanic.