Dear Tom and Ray:

I have an Olds Bravada with 85,000 miles on it. Last month, I had the car serviced (oil, lube, brake work) and set out on a trip. After 500 miles, the front end differential went out. I had it towed to a GM dealership. Two weeks and $3,100 later, I got the Bravada back. They said there was no sign of a broken gasket or a leak, but the old differential had no oil in it, and that's why it had burned up. They suggested that perhaps the other dealership had drained the differential oil and forgotten to refill it. I asked my local dealership if they might have done such a thing. They said that the differential on this car is a closed system and doesn't even have a drain for the oil. They said they've never touched it. What do you think happened? -- Steve

Ray: Hard to know, Steve. To the best of my knowledge, there is no drain plug on this differential. But that doesn't mean the oil can't be removed.

Tom: Right. There's a way to ADD oil, and it's possible to suck the old oil out in order to change it. And your local dealership may have removed the old differential oil with a suction pump and forgotten to refill it.

Ray: Why would they be changing the differential oil in the first place? Hmmm. To make money by performing additional work on your car?

Tom: But in order for this approach to work, they'd have to do, what? Bill you! In which case you'll have them dead to rights, because your repair order will say "change differential oil."

Ray: So you need to check their receipt from before your trip.

Tom: Bear in mind it's also entirely possible that the oil just leaked out very slowly, and the other dealership didn't see any evidence of a leak. In that case, the timing was just coincident.

Ray: And unless it says "change differential oil," "service diff.," or something similar on that repair bill, you'll never be able to prove otherwise. Good luck, Steve.

Which is cheaper, buying or leasing? Should you keep a car forever or dump it after three years, before trouble starts? Find out in Tom and Ray's pamphlet "Should I Buy, Lease, or Steal My Next Car?" To order, send (check or money order) to Ruin, P.O. Box 536475, Orlando, FL 32853-6475. You can also order online.

© 1998 by Tom and Ray Magliozzi and Doug Berman Distributed by King Features Syndicate, Inc.

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