Pinion Gear Backlash Adjustment

[crashone]

Can someone explain pinion gear backlash adjustments to me in simple terms and step by step approach or to a link with that information?

Background: '89 silverado Z71 at ~239,000 started having problems with differential, new pinion gear was installed. Now ~ 3,000 miles later a different mechanic says the whining noise from differential is not having the pinion gear backlash set properly.

She sings like a banshee at 75-80 mph!

What can I do to correct this?

Thank you for the help.

[Dr_Zero]

Check out here they did a show where they showed that not to long ago
http://www.powerblocktv.com/site3/in...reme4x4-videos

[Jimmiee]

You mentioned you changed the pinion gear only? If so I don't think you will be able to get the noise to quiet down. The reason is the ring gear and pinion gears are supposed to be a matched set. If you have a used ring gear and a new pinion you can set it up perfectly and it will still be noisy. That being said if you still want to try to quiet it down you must start by looking at the contact pattern. The pattern will tell you if you need to move the pinion gear or the ring gear to achieve the correct pattern. Once the pattern is close then the back lash adjustment comes into the picture. Remember the back lash can be adjusted by moving the pinion gear and or moving the ring gear. Confused? <G>

[crashone]

Thanks for the replies. Yeah I thought it was going to be a little tricky, more fun in the sun, or headlamps depending on when I get the chance to tackle this.