Piston Slap: Addressing an Eldorado’s seat coupling?
I have a 1984 Cadillac Eldorado with a power driver seat that doesn’t work. All the switches on the door work, but the seat won’t move, like a gear or sprocket is broken. The seat is stuck all the way back—and too far back for average driver. I feel there must be a way to adjust manually.
Would appreciate any help or where to get info! Thanks!
Unfortunately, power seats aren’t like power sunroofs (or moonroofs), with their emergency crank handles to ensure a vehicle’s interior isn’t permanently exposed to the elements. Odds are you can perform some manual motivation to the seat track, once you remove it from both the Caddy and the seat cushions. But if you’re going that far, why not do it right and replace the broken part?
The video above shows the motor’s coupling has gone bad, and that’s likely a weak link on the power seat assembly of every 1980s GM automobile still on the road today. I recommend you take a good look around the power seat track, after removal from the cabin and the seat itself. Look for broken parts, cracked parts, failed cables, and obstructions on the track.
Anything at this point can fail, especially if the Caddy’s previous owners were less than tidy (and allowed debris to get jammed in the system). But I’m gonna take an educated guess that the aforementioned coupler failed inside the motor. You can buy the replacement GM part online, but there appears to be an improved design that might be worth a closer look.
Sometimes parts need to be weaker to ensure the rest of the system remains healthy. These are called sacrificial parts, and their failure is by design. Of course, old plastic from the 1980s is gonna fail no matter what; time is never kind to vintage plastic. So perhaps the upgraded design from Proper Parts ensures this Eldorado will remain functional for the rest of our days on this earth?
Only a visual inspection of the problem will tell the whole truth! What say you, Hagerty Community?
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