Limited slip differential saves your wheels.

Dear Car Talk

Dear Car Talk | Apr 01, 1991

Dear Tom and Ray:

I got myself an '88 Chevy Astro Van. Among its options is a "Limited Slip Differential." To a layman like me, that means that when one of the driven wheels starts slipping in mud or snow, the power transfers to the other wheel to keep me from getting stuck. The problem is my truck doesn't seem to do that. Is my understanding of limited slip differential that limited? Or if it's broken, how can I prove it to the dealer?

RAY: First of all, Martin, your understanding is not limited at all. Limited Slip Differential does exactly what you say it does. It automatically transfers power from the slipping wheel to the wheel that's on terra firma.

TOM: And yours may, in fact, be broken. Keep in mind, however, that if both of the rear wheels are on mud or snow, Limited Slip can't help you at all.

RAY: If your warranty is of limited duration, and your dealer is expressing limited interest in your problem until the warranty runs out, it should be pretty easy to demonstrate for the record that it doesn't work.

TOM: Next time you drive into the dealership's service area, bring something slippery to put under the driven wheel. We prefer Felipo Berrio Extra Virgin Olive Oil. If the Limited Slip works, when you step on the gas, the power will be instantly transferred to the other wheel, and the van will screech away--probably right through the plate glass window and into the customer waiting area. If the Limited Slip doesn't work, the wheel will spin, and the dealer will be convinced. Good luck, Martin.

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One