Hey guys,


I am a first gen guy, and know very little about second gens. Please don't flame me if this is a newb thread.


I stumbled into what seems like a decent deal on a series 5 89 RX-7 convertible. I have been playing tag through email with the seller,and looked at the car a couple of times over the past month. The seller lives in Boston, but the car is in the garage of his summer home on Martha's Vineyard, so it has been a little tough coordinating things. I finally got to hear it run today,and drove it for about 15 minutes. During the test drive the car vibrated pretty badly, at all speeds, and gears, and the vibration didn't go away with the trans in neutral, or clutch pedal depressed.

I know little about the 2nd gen cars, but do know that Miata's of this vintage suffer from vibration issues. The seller thinks it is more than likely from flat spots on the tires, and that may be the case, but I am unsure. The seller says that car has been sitting most of the summer, and he doubts he put more than 100 miles on it this season. Could it be flat spots? Could it be wheels out of balance? Could it be both? Could it be driveline related? Do the convertible RX-7's suffer from vibration issues like the Miata? Oh yeah how tough is it to replace the top on these cars? This one needs a new one. Where is the best place to get a new one for a decent price?

Any help on this would be greatly appreciated.

 

If you have vibration in neutral without the car moving, it's bound to be a broken engine or transmission mount. The convertible chassis is fairly rigid. There's almost 300 lbs. of extra steel to make sure of it.

For tops, I replaced mine for a grand total of $700 installed about 5-6 years ago. Prices have gone up since then, but the top itself came from an ebay vendor for $300. I had a local automotive upholstery shop install it.

 

No vibration in neutral. Only when moving, and not any one particluar speed or gear. It did vary with speed though.

 

Another possiblity is the u-joint in the drive shaft. Common problem. The factory put a non replacable ujoint in the FC. You can find a new drive shaft at Mazdatrix or you can find a thread on this forum regarding a replacable u-joint.

A used drive shaft will probably not last too long. I have replaced mine on my 90Vert twice with 'free' used drive shafts.

Welcome to the Vert world!

 

I haven't bought the car yet, but I am really close. I had never driven a convertible in my life, and the experience was really fun even on a coolish day on the island.

 

On the convertible top we went with The Convertible Top Guys with the canvas version and are very happy with it. We did the install ourselves, following their directions. I've heard shops will charge a lot of money. Search the forum for examples of what people have been quoted.

 

If the vibration is only when moving, the flat-spotted tire idea is reasonable if the car has sat for a long time. It could also be an imbalanced wheel or the rear u-joint like jack mentioned. Trans / Diff Troubleshooting

I've experienced a bad front u-joint, and it made engaging the clutch on hills very interesting. It had a nice metal banging noise until it fully engaged.

 

I had the same problem with my vert. My rotors were bad and tires were not in good shape. Got brakes and a new set of rubber and all is good again.

 

When I got my vert the u-joints were shot. I'd take it to a shop for a pre-purchase inspection. Ask them if they can check the balance of the tires and when it's spinning on the machine you can get a good idea of flat spot issues. And while it is up in the air check the play in the drive shaft. should take all of this stuff about 30 mins- 1 hour. Good luck with the purchase!