Looking For Advice About Tire Wobble With Coker Tires and 40 Ford Steelies

This is kind of a long story, and I'm looking for some advice or anyones opinion, thoughts or anything. It all started when I was building the car. I ordered 4 tires from Coker and got the car drivable. First test drive car shook like hell from 40 MPH and up. The tires are 7.50 x 16 rear and 450/475 x 16 front Firestone Deluxe Champion. I jacked the car up and spun the front tires and found both had a wobble to them. I checked the runout of the front wheels and found them to be fair with the worst being about .060". One tire was considerably worse than the other, so I called Coker and ordered a replacement. The tire came, I got it mounted and had the same problem. This all took place in 2006. For the next few years I worked on the car some and drove it a little. Didn't drive it much because I couldn't stand the shaking. Fast forward to 2009; I decided I wanted to drive the car, so I started to study the problem again. I did a search on the HAMB and found the thread from 2008 about the 450/475 x 16 Firestone tires and found that some people had problems and some didn't. Some people recommended lowering the tire pressure. I lowered the pressure progressively down to about 12 psi and found the problem got better as I lowered the pressure, but it was still annoying. The car pretty much sat until 2010 and I decided to try to fix it again. I found one of the brake drums was warped, so I orded 2 new brake drums and hubs and put them on. Same problem. The car sat until this year and I decided I was going to fix it. I ordered 2 new tires from Coker, only this time I ordered 500/525 x 16 so there was no chance of getting some of the presumed bad 450/475 x 16's. I got them mounted and one runs true and the other had tread wobble again. I figured the wheel was bent and found a shop 50 miles away that would straighten it. They straightned it and said it is probably better than new. I took it home and the tread still wobbles. I called Coker and they said I would could buy a new one and send them the old one on my dime and if they didn't find a problem they will send it back on my dime and I'm stuck with it. They recommended I have the radial and lateral runout checked on the tire. I took it to the shop and the machine said it exceeded the limits and didn't give a number. The wheel passed the runout test with the front at .013 and the back at .050. He turned the tire 180 degrees and it was the same. I already have 3 of the 450/475's and I don't want to end up with three of these tires too. I have already bought five tires trying to fix this. Here is a short video of the tire wobbling. I have spent about $1500 trying to fix it and am about to give up. If anyone has any ideas, thoughts or anything I would like to hear them before I scrap the car. Do you think the tire is bad?

 

about the only thing you can do is have the tires shaved and then road-force balanced

 

Bias ply tires are real prone to flat spot if the set for prolonged periods and until they warm up will tend to wobble up and down,,

I'm not saying that the tires are not bad they very well could be,,have you talked to the guys at Coker?

BTW,,the bias ply tires are not radials so don't expect them to preform like them,,why do you think few company's produce bias ply tires anymore.

Are the rims true? HRP

 

Sorry...in the vid it appears that the rim is wobbling...am I looking at something wrong...is that not the rim on the right of the tire...

 

im having problems with my tires to, they arent cokers but my tires wobble to,not sure how much is acceptable

 

So you've replaced the drums, did you check run-out on the spindles? Another thing to consider is flatspotting.

Bias ply tires will develop flatspots from sitting for long periods of time. Sometimes they smooth out after you've driven on them, sometimes not.

Balancing tires, particularly new tires is a bit of a waste of time. The tire has to go through several heat cycles before it finally settles on it's permanent shape.

At that point, that's when you should get them re-balanced and then possibly shaved.

 

Put a dial indicator on the hub, with no wheel mounted.
Put a dial indicator on the wheel, installed on hub, no tire.
Put a dial indicator on the tire, wheel, hub as installed to run down the road.

Remember to measure radial and axial run out on the inside and outside edges of each component. Write down everything. Swap wheels and tires from left to right and repeat. This will get you to the component at fault. Tolerance is pretty fat on these things at certain speeds, but even a small run out can have a sweet spot at a speed you frequent that will result in a wobble, shake or vibration that is intollerable.

IF the wheel and hub are OK, you may need to shave and road force balance a tire, but I have heard more than a few first hand accounts of dyna beads solving some tough issues.

 

Bias ply tires don't behave like radials..cross the center line on a crowned ridge..you'll feel it...but it still looks like somethings off to me...

 

It isn't the car it's the tires you chose to use. Plus sitting around for six years doesn't help any tire from any manufacture.
You might get the tires trued and that would help some but it isn't going to help with the lateral runout. Different tires are all that are going to help with that.

Right now I'd borrow another set of tires and wheels that were known to be good and run the car down the road with them on. That will prove to you that the car it's self is ok. They don't even have to be the right size just close and have wheels that bolt on the car.

Outside of truing the tires you have already done everything that I did in the tire shop and later in dealerships to fix similar issues in the early 70's at the tail end of the bias tire era. It sounds like your rims are about as true as any vintage steel rims you will find. They are a lot closer than the allowable tolerances for oem wheels in the mid 70's at any rate. If the tires were mounted correctly and balanced correctly and you already turned them 180 degees with no improvement I would say you need different tires.

I would do as 3wLarry suggested though and have the tires shaved/trued and then have them spun balanced on the car if you can find a shop that has an on the car balancer. if they have one that uses a strobe rather than the Hunter style hubs so much the better.

 

What you are seeing on the right side is a rib on the sidewall of the tire. This tire just came on Monday, there hasn't been weight on it for more than a couple of hours.

 

ROAD FORCE BALANCE

worked for me.

Rich

 

All it looks like in the video is you have high and low spots on the tire, Need to have it shaved and trued.As stated earlier,bias ply tires that sit long periods of time will ride rought the 1st few miles.

 

Not the first post on bad Coker tires. Wouldn't even think about buying them.

 

I've seen them wobble after they been shaved too. I had a set that were just plain terrible. Jumping up and down and shaking the front end violently. Nothing to do with them handling like bias tires. A little skitching around is nothing. What these tires were doing was criminal. I haven't had a problem since I took them off my car. Those front tires are only good museum cars.

"I called Coker and they said I would could buy a new one and send them the old one on my dime and if they didn't find a problem they will send it back on my dime and I'm stuck with it."

That's great right there!! What do you think they are going to find? These tires are great because you have nothing better to do than spend hours and hours aligning and truing and shaving and balancing on the car and off the car and blah blah blah. Then when you do report what you find it always comes back to them saying that ultimately there must be a problem with your car.

You should just be able to mount the tire, balance it and run it like any other tire. Then if you can't get those to work, we've got these very expensive radial look alikes for you to try. Seems like everyone sinks a grand in a set of bias that don't work very well, then another or more in a set of bias look a likes. I'm at least glad I never bought the look a likes.

The problem should be dealt with by the manufacturer. I am not sure if Coker doesn't just sell these small front bias tires.

 

It is possible to orient a tire with simple runout on rim with siimple runout with high spots opposite and reduce the runout of the assembly. By simple runut I mean measured runout that has a fairly smooth sweep from a single low spot to a single high ~ 180 degrees opposite. Radial and axial/lateral runout must be measured separately.

 

I would check the wheel, voodoo jim had this same problem, several sets of tires. turns out it was the wheel. we changed the hubs, shaved tires, had static balanced, years of messing around, the center where wheel bolts was bent.

 

I had a brand new rim from Coker that was bent from the start. I contacted Coker and they were happy to send me another rim. My dad recently had balancing issue with two new Coker rims. After calling Coker they asked if we had "hub balanced" them. (Uses a bolt up hub to bolt the rim just like your lug nuts to the balancing machine rather than the cone type so many tire installers use) Had a hard time finding a company with this machine but after the balancing the wheels were fine. Good luck. Don

 

This is why we used to put cars up on blocks when they were going to sit for any length of time. Depending on the weather a bis ply tire will flat spot overnight. The usually smooth out when they get some heat in them.

This is not to say that the OPs tires don't have a problem. Perhaps at least on the newer ones it is something that can be worked out with coker.

It was mentioned that bias ply tires don't perform the same as radials this is absolutely true. It is like getting into one of our cars and driving it after only driving a late model all your life. they are just different and can't be expected to perform like a late model or a newer up to date product. it is just the nature of the beast.

 

After a quick review of your video post it appears that the tire is not revolving concentric to the spindle hub center line. This produces a high spot in the tire and a lumpy or vibrating ride. This is a quick way to check for out of round, if boost the air pressure to 30 lbs + you will experience a very rough ride or harmonic as you increase speed almost immediately . If you drop the air pressure down to 18 lbs the vibration is delayed until a more significant speed is reached.

The easiest way to determine a tire issue is to find someone with wheels and tires already mounted with the same bolt pattern as your ride and swap out the wheels for a test drive. They don't have to be the same size, just being used with no major evidence of balance issues.. If the tires don't vibrate on their car they shouldn't on yours. If their tires produce a vibration then you have to address issues with the the hub or brake drum balance on your car. If the swap tires eliminate the vibration problem you can then address the out of round tire issue.

From the video it appears that the tire is out of round.

 

I have seen many sets of Coker tires with run-out. In fact, I would say that it's the rule rather than the exception.

 

All the advice you guys are giving is nice, but he's already changed tires and wheels and it looks to me like that tire is just not fricking round! If that were a radial it would shake just as bad at speed. My father, who worked for Goodrich at the time, stopped buying Goodrich tires in the late 1970s because he AND a friend had the same exact problem with brand-new radials. They gave both guys the same runaround ("must be your wheels, must be your car, etc.") NO new tire should be expected to roll badly! I have owned several cars that drove smooth and straight with bias-ply tires on them. This is a whole other issue.

Put on a set of borrowed wheels and tires like Mr48Chev said and that will answer all the questions everyone has. If they solve the problem then it's either wheels or tires, and it sounds (and looks) to me like it's the tire.

Personally, I would recommend switching to a different manufacturer if you can find one.

 

I worked for years at a place where we made the Duesenberg II, a luxury car. We used Coker tires and ended up buying a tire shaver that we had to use on almost every tire. I think the tire is your problem.
Tom

 

The local tire shop I use is the best place in town for drivability issues like you are describing, even new car dealerships bring them cars with tire/wheel vibration issues. Despite the possability of losing a sale they will try talking customers out of using Coker tires because they've had so many problems with Coker Tire's QC issues.

 

Less advertisinig , more enginerring !

 

There are wheels on the market that are "hub-centric" and others that aren't and those that aren't can be a problem when they are placed on a cone type arbor on a balancer. This can be a problem on any car with any tires, on or off topic, steel or alloy wheels, bias or radial tires.
Im amazed though, at the reply's like "Have you checked the wheels?" when the OP has even posted runout figures!
Jeez!!!!!!!!! Do some of you people even READ THE WHOLE POST BEFORE YOU POST??????????
Dave

 

I had the same problems with coker bias ply tires. I tried everything but couldnt get the shake or handling I wanted. I finally bought a set of diamondback radial tires and solved the problem. It was radial tires to drive the car or sit and look at it. I have put about 6 thousand miles on the car and havent had any problems since.

 

I have had a ton of issues w/ the 450/475. A friend of mine suggested upping the air pressure in the tire to 45lbs. It sounded kind of crazy to me, but helped 100 percent. Still not perfect but I can cruise 65 no problem at all. It starts to shake above that, but I think my buick drums need balanced.

 

Whats your tow in set at ? Try some Dyna Beads !

 

The 45/475 -16's are known to be bad. You couldn't give me a set of them. I know from experiance.

Now I am suprised Coker is making you send the tire back on your dime.

When i had a bad set they took them back, no questions asked and paid for the shipping. A sign they know they have a problem.

We went up a size to 500 -16 and had no problem.
Clark

 

You can shave the tire but you shouldn't have to go through all that bullshit when you're paying good money for a product.

I've seen as much as a 1/4 inch shaved to get them round.
Clark