Chevy Impala SS Forum banner

1 - 5 of 5 Posts

·
Premium Member
Joined
·
405 Posts
Discussion Starter #1
I've been having a highway speed vibration issue with the OEM wheels and stock size (255/50ZR17 Riken Raptor ZR A/S) tires on my 1995 Impala SS that I haven't been able to eliminate with an alignment and balancing. The technician who last balanced the wheels and tires noted that all 4 had lateral run-out that exceeded GM specs, so maybe that was part of the problem. These wheels were purchased direct from GM 20 years or so ago, have roughly 30K miles on them, and have never been hit, so I have no idea why they're not true, but anyway...


It's been getting harder and harder to find tires in the OEM size, so I decided to try a different size with the same diameter to keep the speedometer accurate. I decided to go with 255/45ZR18s at all four corners. I selected a set of 4 Continental ExtremeContact DWS06 tires.



That meant looking for 18" wheels. I wanted hub-centric wheels if possible, so after a lot of looking I decided to use US Mags Standard U104 wheels (18x9, offset -12, backspace 4.53, hub size 78.10, part number U10418907352). The combination of offset and backspace means the tires sit about 0.5" further out of the wheel well, but it all fits just fine.



I bought the whole kit as a package from Extreme Customs for $1,585.26, with center caps, lug nuts, shipping, and high speed road force balancing included. I just finished a road test after installing them, and the vibration issue is gone. I also have a much larger selection of replacement tires in the future, and my speedometer is still spot on. Overall, I'm happy with the swap. One of these days I'll see about getting the OEM wheels repaired, but with the limited selection of tires I don't know if I'll ever go back to using them.
 

Attachments

·
Registered
Joined
·
2,907 Posts
Hi, glad you solved it and know it is either the tire or the wheel that was on the car.

Maybe you can test the Riken's on diff wheel to prove the OEM wheel is the issue ?

Car looks sharp !
-ALF out...
 

·
Premium Member
Joined
·
405 Posts
Discussion Starter #3
Maybe you can test the Riken's on diff wheel to prove the OEM wheel is the issue ?
-ALF out...

Maybe, but I don't have an extra set of wheels. I also haven't had any luck finding a local shop that can diagnose and repair whatever is going on with the original wheels and the Rikens. The wheel repair places I spoke with all either went silent after I sent them pictures, or claimed that they couldn't do the work. I did find one national chain that said they can do the work, but they won't have a local franchise in operation until August. I'll work with them when they're ready and report back.
 

·
Registered
Joined
·
7,983 Posts
Wheels look GREAT!! Can't beat that old classic "Crager" look.

On those old wheels/Tires...

As long as they are the same diameter as your new wheels, maybe just bolt each 1 on the Front 1 at a time to see if they all vibrate or just 1. I think the Raptors are directional so 2 on LF and the other 2 on RF. See what happens, maybe its just 1 wheel/tire?
 

·
Premium Member
Joined
·
405 Posts
Discussion Starter #5
Thanks for the suggestions, guys. I measured the lateral runout on all 4 of my original wheels using a dial indicator, and they all exceeded the OEM spec of 0.030" (they ranged from 0.060" to 0.1"). I don't know if that by itself is enough to cause the vibration, but at this point I'll probably just wait until I can get a pro to look at them.



I actually looked into the Cragar SS wheels, but they don't make them in diameters larger than 17". I thought these came pretty close to the same look, though.
 
1 - 5 of 5 Posts
Top