1990s 1996 Seville

[eldoguy]

A friend has a 1996 Seville that has randomly shifted from the 4th gear to 3rd gear while driving.  This resulted in restricting the speed to about 50mph.  Checking with at least two dealerships he was told that they did not service Cadillacs older than 10 years and that Cadillac Corp. did not produce parts beyond 10 years.  Where can he go to get this problem corrected?  Might it also stem from a faulty computer?  Any other ideas?

[The Tassie Devil(le)]

Any Auto Trans Shop should be able to sort out the problem, and a lot cheaper than a Dealer.

For them to say that Cadillac didn't produce replacement parts for any car older than 10 years seems like a cop-out to me, as even though they aren't making parts for cars older than 10 years, they will be holding parts for longer, or until they run out.

From what I understand, manufacturers have to, by law, be able to supply replacement parts for up to 10 years after the ceasing of production for that model.   They do this by estimating how many parts will be required through normal wear and tear, and make that number and store away.   If there is a rush on these parts, and they run out, there is no recourse.

This happened here in Australia where there was a shortage of Frames and Passenger Side lower Control Arms for some models.   It turned out that with the Lower Control Arms, the Passenger Side ones got destroyed more often than the Drivers Side ones due to hitting curbs, and general crashes.   The Frames suddenly got used up by the Aftermarket people that found they fitted perfectly beneath the sports cars that they were making, so they bought the up the stocks.   The Factory couldn't make any more because they had destroyed the moulds.   The Factory couldn't be prosecuted because it wasn't their fault that someone else had found a reason to purchase everything.   They had done their due diligence to make what was required.   I once saw the stacks of frames, and it was huge.

Bruce.

[TJ Hopland]

That would have an electronically controlled transmission so its likely that the computer is telling it to downshift if that is what is actually happening.  Its unlikely a 'bad' computer, most likely the computer is getting bad information from somewhere that is making it think that is the correct gear to be in.  A scan tool that can read live data would be my first step to just see what the computer is seeing.