Chevy Impala SS Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
490 Posts
Discussion Starter · #1 ·
I'm still fighting wandering and bump steer with my Impala. I've had the front end aligned, played with tire pressure, etc. Now I've been told that maybe the offset on my aftermarket wheels is incorrect. They are 18x18.5" wheels with -6 offset. Can you wheel gurus give me some insight on this?
 

·
Registered
Joined
·
1,175 Posts
what tires are you running? when you say wandering is the car following dips and groves in the road. im going to guess you meant 18x8.5 the size of wheel and offset shouldnt be a problem at all.
 

·
Registered
Joined
·
490 Posts
Discussion Starter · #3 · (Edited)
The tires are BFG G-force Super Sports. The car follows rain grooves, and even small bumps upset the steering, causing the car to jump either left or right. Even on smooth pavement, the car wanders.
 

·
Registered
Joined
·
1,175 Posts
from experince, im going to say its your tires. in the past ive notice my wagon do the same and even more in certain areas around town. after swapping tire brand i noticed a huge differnce. i would try a differnt set of tires and hit the areas where you notice the cars does these things to see if you see a significant difference.
 

·
Premium Member
Joined
·
10,064 Posts
The offset shouldn't be an issue. -6 on an 8.5 wheel is not ideal, but not off so much as to make it wander.

I'm willing to be the issue is in the suspention and tires. BFG's dont have the best reputation... As for alignment, do you have the specs it was aligned to? If so, I'd run them by Navy lifer.
 

·
Registered
Joined
·
490 Posts
Discussion Starter · #6 ·
The alignment was done to the specs I got on this forum. I originally put Kumho tires on the car, followed very shortly therafter with the BFGs. I didn't see much difference in the two brands, they both wandered.

The suspension has been thorougly gone over by a competent shop. The did find a bad idler arm, but replacing it did nothing to help my problem. The rest of the suspension looks fine.
 

·
Premium Member
Joined
·
10,064 Posts
Here's a longshot. My ol wagon had tons of play in the steering and wandered so bad my wife refused to ever drive it. On day I had the power steering flushed and it tightened up considerably. How's your PS fluid looking?

Lastly, I'd borrow a set of wheels from someone ho's car doesn't wander. If it rides better, then you know its the tires. If it doesn't, then its the suspension. It has to be one or the other. Thats a good way to find out.
 

·
Registered
Joined
·
1,643 Posts
Comments are welcome of course, but anytime you deviate from the OEM wheel offset you run into the probability of scrub issues. How that plays into the symptoms you are experiencing is unclear but tread pattern can be a factor worth reviewing as well.
There is more to choosing a wheel than just looks and being able to squeeze it into the wheelwell.
 

·
Registered
Joined
·
1,643 Posts
Why not just say you have no idea, eh?
If you want to interpret my post in that fashion, OK...
I'm still fighting wandering and bump steer...
...or I could have stated the obvious that was implied with my previous wording. Anytime a wheel deviates from the suspension's engineering specs, pandora's box has been opened. Go back to a wheel that conforms to OEM offset specs and note any changes
in symptoms.
The offset shouldn't be an issue. -6 on an 8.5 wheel is not ideal, but not off so much as to make it wander....
I interpet your post as to imply additional tire scrub is acceptable, that it is not that important.

AFAIC, throw tire diameter and width into the mix and that 'less than ideal' scrub becomes less harmless.
Then again, I'm not the expert here. That is why I stated comments welcome. :)

I've learned a long time ago, when it comes to diagnosing member's complaints, contributing issues are left out of the mix.
Eliminate the variables!
:chuckle: Reminds me of a person maning a computor complaint phone. After going through possible issues with a disgruntled customer, he finds out the customer didn't have the computor plugged in to a working power source.

IMO and in summary, messing with the scrub radius on a vehicle that sees modest or barely reaching legal hiway speeds and puts on but a few thou miles @year is one thing. Actually driving the vehicle achieving performance speeds and putting miles on it is quite another.
 

·
Premium Member
Joined
·
10,064 Posts
Either you're making more sense this time around, oI actually took time to think about what you said. I'll allow that both factors could be at work.cwm4

Nonetheless, I still hold that swapping wheels with another vehicle is the ultimate truth teller. The OP has a wagon (a mighty nice one, at that.) swapping wheels with that will immediately identify the offending element. If the vehicle no longer wanders, then the wheel and tire combo is at fault. I still want to blame the BFG's, as over the years I've heard that they do wander.

But I myself claim to be no expert, either. What I do is compile information based on experience, mine and others. And I know how to use the search.:D
 

·
Registered
Joined
·
1,643 Posts
Either you're making more sense this time around, or I actually took time to think about what you said. I'll allow that both factors could be at work.
Yeah, who knows, maybe some of each!
I've read some of my posts from years past in various forums and think, wow, what brillance! Did I really compose that? Then I can reread (more than once) other past posts in the present and wonder what was I attempting to say?
Nonetheless, I still hold that swapping wheels with another vehicle is the ultimate truth teller.... Swapping wheels with that will immediately identify the offending element. If the vehicle no longer wanders, then the wheel and tire combo is at fault. I still want to blame the BFG's, as over the years I've heard that they do wander.
Unfortunately, even if it solves the problem, that wheel/tire swap would be comprised of two variables which would not allow us to pinpoint one or the other as at fault or percentage of each. However, we do agree both can be factors.
 

·
Premium Member
Joined
·
10,064 Posts
True, once you decide that the wheel and tire combo is at fault, then you got more work to do.

I'd dig around for some used 245/45r18 eagle RSA's and see what they do on the rims IF the wheel/tire combo is at fault. I currently have about 12 of them in my basement because I run them on my S10 on a 18x8.5 rim. No wander whatsoever.

But I'm thinking too much. And we haven't heasrd from Jon in a bit, so all this might be moot.cwm3
 
1 - 15 of 15 Posts
Top