Balancing BFG KM2's on an FJC

[BretEdge]

I've got a 2007 FJ Cruiser with a 3" lift and 285/70/17 BFG KM2's on aftermarket rims. The tires have about 18,000 miles on them and they've never been properly balanced despite multiple attempts by the tire shop here in Moab where I bought them. Currently, between about 45-65 MPH the steering wheel shakes pretty badly. Below those speeds it's relatively smooth (for a mud tire) and above that it's better, but still rough. Prior to these tires I ran Wrangler MT/R's in the same size and never had this issue. Am I the only one with KM2's who can't get them balanced? Any suggestions aside from switching to a different tire? I doubt I'll ever buy another BFG tire after this experience.

 

[Derek24]

Might be the aftermarket wheels. Try running factory steel wheels or aluminum and see if that helps. Then you can factor out either or. I agree with you, my brother had the MTRs and they were smoooooth!

 

[BretEdge]

Might be the aftermarket wheels. Try running factory steel wheels or aluminum and see if that helps. Then you can factor out either or. I agree with you, my brother had the MTRs and they were smoooooth!

I was running factory rims when I bought the KM2's and still had the same problem. I appreciate the suggestion, though.

 

[Cabrito]

It's a known FJ issue.. My stock setup has been like this since day one. Changed tires to some Coopers with a more aggressive tread and it got worse. Multiple balances done with mild temporary results. Most complain about it being between 50-60 mph.

 

[Derek24]

Weird. I just bought a 2011 Fj that came with 295/70/17 Toy open Country MTs, brand new on factory wheels and I have no shaking at any speeds. Hopefully it stays that way....

 

[Zac808]

My km2 255/85/16s were a PITA to balance as well. The tech had to spin each wheel about 5+ times to get them in. Each time adding or removing weight. Zero problems wih shaking.

cent frum my fone so don't cumplane about spelling or grammer

 

[BretEdge]

It's a known FJ issue.. My stock setup has been like this since day one. Changed tires to some Coopers with a more aggressive tread and it got worse. Multiple balances done with mild temporary results. Most complain about it being between 50-60 mph.

I never had a problem with mine until I had the KM2's installed. It had no issues with the stock tires or the MT/R's.

 

[ebg18t]

I read several threads of folks using dynabeads with km2's to eliminate the balancing issues.

 

[austintaco]

I just put 255/85/16's KM2's on my 03 Tacoma DC, and they were smooth for our 3000 mile trip. I had a set of Cooper in the same size that were vibrating, but I think I finally figured out that the issue with them was a misaligned coil that was causing cupping.
I am running stock 4runner wheels on my tires and they have to be balanced as lug centric to get them right. Are FJ's lug centric as well? Maybe the shop is balancing them as hub centric.

 

[loup407]

FJCs ARE hub-centric. I am on my second set of KM2s on my 2008 FJC and have not had a problem with balancing the wheels. There was the time I thought I'd lost a weight, but turns out I had a fair bit of dried mud on the wheels (on the back side, hard to see) that once I washed off, the shimmy disappeared.

 

[BretEdge]

FJCs ARE hub-centric. I am on my second set of KM2s on my 2008 FJC and have not had a problem with balancing the wheels. There was the time I thought I'd lost a weight, but turns out I had a fair bit of dried mud on the wheels (on the back side, hard to see) that once I washed off, the shimmy disappeared.

I definitely don't have any mud on the inside of the rims but I will check with the shop to determine whether they're balancing the wheels via a hub or lug-centric method. Thanks for the idea.

 

[austintaco]

One more thing that came to mind is the lug nuts. Some have a tapered shank and some are flat with a washer. Balancing them correctly (hub centric or lug centric) and then using the correct shank matters too. I forgot that I ran into this issue with my Tacoma and the 4runner rims. Your shop in Moab should be able to tell you what lugnuts your style of wheel will use, but you might want to ask.

 

[ssc45]

I had the same problem when I first got my KM2's. A friend rebalanced them on his machine and to this day no problems. I am on my second set with aftermarket rims and all is good. You can read about it in my write up. I think I was one of the first FJ's to get the km2's. Here is the link http://www.fjcruiserforums.com/forums/wheels-tires/37079-report-bfg-km-2-a.html
If I remember it is a road force balancer machine. I always run weights on the inside and keep an eye on the inside of your rims, as dirt and mud can throw off the balance.

Cheers, Steve

 

[STREGA]

My KM2's (255/85-16's) have been very smooth running up to 80 mph, I haven't been over that speed though and have about 20k on them as of now. I did have a little bit of a issue with the OEM KO's, one tire in particular but was able to get it to balance out eventually.

 

[BretEdge]

Thought I'd post an update so all those who responded and followed the thread will know how I resolved the balance issue. Chip's Grand Tire in Moab installed Magnum Plus Balancing Compound, which are "ultra-smooth microbeads" that are placed inside the tire. The company website looks like something from the 90's Geocities era but the product seems to be getting the job done. I've got about 300 miles on the tires with the Magnum product and it's a super smooth ride at all speeds up to 85 MPH. If you're having balance issues, this might be something to consider.