PK

I just changed to new tires - BF GoodRich All Terrian TA KO. 265/75R16.

Changed from: same size but less agressive tread (BF Goodrich Rugged Terrain)

It seems like my truck now "bounces" or vibrates at around 40 mph.
I've had it back to the shop to re-balance the tires. They were off about 1.5 oz. on each tire, but he said it shouldn't have made that much difference to a truck my size.

After they re-balanced them it feels about the same.

They checked my stock rims and said they look fine.

Any suggestions or am I just feeling the more aggressive tread?

Thanks in advance.

runamuk

Sounds as if they did not check your track bar, tie rods, alignment.

The infamous death wobble awaits you! Get it checked out pay special attention to caster and camber issues!

Rick

PK

They did the once-over and said that my front end looks tight and true.
They thought everything seemed good. ( However instruments were not used).
Just seems a bit strange that no problem existed with the old tires but as soon as new ones were put on, I started getting this problem.

Mopar1973man

The only thing that rings a bell with me is a bad tire that is out of round. Is there any tires with a lot of weights on it? If it got more than 2-3 ozs. of weight I would look that one over.

Also try rotating the tires (Front to the rear and rear to the front) and seeing if the problem changes.

GSP

Check the DOT #'s 0n all the tires. I think they should all match from the same lot of tires. Maybe you have a bad tire. I got a tire once that was actually larger than my other 3 but had the same size marked on it.

I also had some wights that got knocked off by my brake caliper .

SoTexRattler

Take them to someone with a tire machine that puts a real load on them via a roller as they check for roundness.. Discount Tire has such a machine. I took it back twice for the 1st rotation and re-balancing and on the 2nd trip back after I wasn't happy, they put it on the "other" machine and found two tires that were causing my bed to "hop" or "bounce" only at 45mph. One tire was the worst, they replaced it. The other was curable by rotating it on the rim to neutralize it's runout with the rim's very slight OEM runout. Fixed it!

K.

Tate

I'd advise against one of those road-force balancers. When I was working at a tire shop, we had a lot of vehicles coming in for vibrations after being balanced on the road force machines. I don't know what the parameters they were using, but we could easily see the runout by eye on our balancers. They would never pick up seperations with those machines. I balanced the tires on my moms truck after going to the dealer several times for the issue, had two seperated tires on the front. Pretty hard to miss the bulges when you actually look at the tire spin.

Are you running the same pressure in your tires as before? Different pressures will give you different rides, which may be part of your problem.

Danderson

I had K'O's on my truck for 16,000 miserable miles. Vibrations started from mile one and persisted despite multiple re-balancings. Seemed like a sturdy tire but "hopping" drove me nuts. I recently replaced them with Toyo M-55's and voila,back to normal. These tires are louder than I'd like,but even with load range "E" they ride better than BFG's with "D" ratings.

snowrodeo

pk,
i'll echo what mopar1973 just said. i just got back from les schwabs just now. had new toyo's put on about 200 miles ago and its been a full time job to keep my truck in my lane at freeway speeds. dart back and forth bad. they found one tire out of round. replaced it. problem solved. prolly more common than you'd think, that a new tire can be defective, just from the way the techs at the shop acted....

Mopar1973man

Just even place a bad tire on a spin balancer and you should be able to see the swell in the tire as it rotates. Once again the tire will require a large amount of weight on one side inside and outside of the rim.

Just for kick and giggles have them take the tires off and check the rims for true. All that leaves is tires then huh???

js

check the tires. i bought a set of michilens for the wifes car and drove 10 miles and went back. everyone of them was out of round . 4 new tires again and everything is great. they do make bad tires every day.

Tate

Thats pretty surprising you'd get 4 bad michelins, especially at the same time. When I worked at the tire shop, I could count on both hands how many bad michelins we had, all the others, there was no point in keeping track, too regular of an occurance.

SoTexRattler

Dunno whatchacallit...
First they mounted the tire and rim to a precision mounting flange that takes away some of the regular balancing machine plate errors. Next they entered the tire brand, type and size into the machine so it knew exactly what to expect. Then this machine had a pneumatically actuated measuring roller wheel that applied known rolling pressures against the tire as it SLOWLY rotated and measured the runout. With this, the machine was able to quantitatively MEASURE the runout of the tire under load and could quickly identify if the tire had a "lump" or if the tire was just uniformly eccentric(simple radial runout). Also there were two 2-axis sensors that were placed up against each lip of the rim measuring its inboard and outboard axial and radial runout too. The eccentricity of the rims was measured simultaneously and they simply rotated the slightly out tire on the rim X degrees from an index mark and the net was essentially zero runout. With this machine they determined the stock rims were good, one tire was definitely bad and was replaced 100% under mfr's warranty, the other was just slightly out. THEN it ran the tires in simple dynamic balance mode (without the load roller) and determined where the weight should be just like the run-of-the-mill tire balancing machine would do.
End result? No more 45mph "humping" and a much smoother ride up to 70+mph(and beyond ). Also, IT made the GO/NOGO decision on the replacement of the tire.. No weasling,lying,reluctance, etc... "Tire is defective, excessive radial runout...".
I am sure some of these machines can be misused, misoperated or misinterpreted.. But, I was VERY happy with the operator and the end result.

K.

PK

Just got back from having my tires rebalanced for the second time!

This is driving me crazy.... They checked all tires for defects/roundness etc.
Looks like one of my rims is slightly out....... Its throwing everything off.
They tried 3 sets of new tires all with the same results.
Guess I need to find a rim at the autowreckers or Maybe I can talk the wife into a set of customs.

Thanks for everyones help.

Amos

I agree with Danderson. The BFG All terrain KO's I had (265/75/16) were the most expensive and yet worst tires I have ever had. I'll admit that they worked great even in 24" of snow but on any other regular surface (dry pavement, wet pavement) were terrible. They had very bad "on road" manners and lasted only about 18,000 miles to boot. It may have something to do with the D load range but either way unless BFG drops the price to $50 a tire I'll never get them again.