...is it worth it?

I have a pesky front-end vibration that I cannot get rid of. Tie rods, all bushings, and all ball joints were replaced in the last month or so. I replaced the LT1 steering shaft with a reclocked LS1 unit. If I do the "jack the front, grab the wheel at 12 and 6 o'clock and shake /grab at 9 and 3 o'clock and shake" test and everything is tight. Alignment was done ~2 weeks ago by probably the best suspension shop in this part of the state. I have staggered C4 ZR1s with new tires all around that I purchased used.

The vibration is speed-dependent which makes me believe its the wheels/tires. It starts around 5mph and progressively gets worse til around 60mph then, oddly, starts to go away. At 70mph its still there, just less. Thinking a weight may have fallen off, I had one shop balance all four wheels/tires and a second shop check them out to be safe - both using the spin-type balancing machines.

Before I part this POS out, would a road force balancing help and does it sound like what I need?

TIA

 

In my opinion it is worth it. We bought my wife a used 2012 Malibu with stock 18 inch wheels. They had a bounce in them when we first got the car that was very irritating so I took the wheels off the car, cleaned them and took all the weights off and carried them to my local Goodyear. Goodyear balanced them, put them back on the car and still had the bounce. At this point I was convinced I had a bent wheel. I then took the car back to the dealership and had them check the wheels out. The first thing they did was a Road Force Balance, completely fixed the problem.

Not to say this will fix your problem but it worked for me.

 

Sounds like one might be out of round or just needs a new balance job. Did they spin them without tires to check the run out?

 

no, I purchased the wheels with the tires already mounted

I did, in preparation for taking my ZR1s to Discount Tire (local one has a history of jacking fbodies by the fender and ruining them), remove them and put my 16" stock wheels/tires back on and oddly, the vibration is still there...

now, I'm thinking:
1) weight fell off stock steel driveshaft
2) bent axle or
3) axle bearings going out (hopefully)

 

Don't rule out a bad U-joint either

 

Im off tomorrow (tues) so I'll be putting the rear on jackstands and letting it idle in gear - what should I look for and where?

 

If you having problems with balancing. A road force balance with a good tech will make all the difference. The tech should be able to give you a final run out. If you are having issue try to get it at 15lbs of road force or under. If the tire is new it could be out of round which is covered under most warranties.

 

Thanks Rudy! The tires are new but I bought them already mounted from another member so no warranty... either way, my local Discount Tire can do them for $10/ea

 

Call around and get quotes on road force balancing. In my hometown area, only 3 or 4 places could do it and the caddilac dealership was actually the cheapest (surprisingly). Something like $14/wheel iirc.

Personally, I did it on my firebird because it just makes me feel "safer" at high speeds and I can vouch it does make a difference on some cars. It's a more precise balance than a traditional balance and I figure if I'm going to drive 100+mph sometimes, precision on moving parts is never a bad idea.

However, if the vibration continued with different wheels on the car, it probably isn't the wheel lol.

 

I personally think road force balancing is more of a sales gimmick than anything. Out of all the times I have road forced tires or forced match them I can think of maybe 2 or 3 times it actually did anything. That's just my opinion tho.