To find a suitable replacement, you need to determine your van's original rear axle specifications, including:
* Axle width: Measure the distance between the wheel mounting flanges. This is crucial as axle widths vary even within the same vehicle year and model.
* Gear ratio: This impacts your vehicle's performance. Check the tag on your differential cover for the ratio (e.g., 3.08, 3.73, 4.10). You'll want a similar ratio for optimal performance.
* Bolt pattern: This is the spacing of the lug nuts on your wheel. Make sure it matches your current wheels.
Once you have these specs, you can start searching for a suitable replacement. Here's what you should look for:
* Other GM 10-bolt axles: Similar-year GM trucks and vans (like a C/K series or Suburban) may have usable 10-bolt axles. However, you *must* verify the width matches your G20. Even then, some modifications might be required.
* Aftermarket posi-traction units: It's possible to get a posi-traction unit (like a limited-slip differential) installed *into* your existing differential housing. This is often a more cost-effective option than a complete axle swap if your existing housing is in good condition. A reputable shop specializing in differentials can advise on this.
Caution: Simply finding a 10-bolt from a similar-year GM vehicle is *not* a guarantee of fitment. Variations in wheelbase and other factors can lead to incompatibility. Improper axle selection can lead to drivetrain issues, handling problems, and potentially even dangerous driving conditions.
Recommendation: Take your van to a reputable differential shop or mechanic specializing in classic vehicles. They can identify your axle's specifications, advise on suitable replacements (including aftermarket posi-traction units), and handle the installation to ensure everything fits and functions correctly. They'll have the expertise to avoid costly mistakes.
