76 severe steering shimmy - Kings wheels & KO2s

#1
Hi all,

After finally replacing the stock GXL wheels on my 76 (2008) with Kings steelies (-55 rear, 0 front) and BFG KO2s, I've noticed a severe steering shimmy above 70km/h. On freeways it's bad; on windy roads it's downright dangerous. The steering wheel can rock 2-3 cm in either direction when it's bad.

Has anyone experienced similar after changing wheels/going up a size, or using Kings rims or BFG KO2s?

Troubleshooting so far:
* Rotated tires, as much as I can with the different offsets
* Returned to the tyre place and had them re-check wheel balance, all was okay
* Visual check of tyres/wheels for defects/round issues
* Checked and re-greased tie rod ends
* Adjusted wheel bearing nuts - I thought this would fix it, as the left was a little out. After adjusting and test driving, the problem is possibly worse

Tomorrow's plan is to put the old GXL wheels back on the front, then depending on the outcome, on the back as well. I probably need a beefier steering dampener, but I'd like to minimise this issue before hiding it with a shock.

If none of the above helps and things are okay with the GXL wheels, it'll probably mean a fight for a refund on the wheels and tyres, which won't be fun.

FYI the 76 is an upgrade from a 75 series which had BFG 33s on old Sunnies, and never had this problem; so it not just that the 76 is agricultural. It's a real problem.

Any ideas would be greatly appreciated; I'm willing to try anything at this point. Cheers!
 
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mac_man_luke

Well-Known Member
#3
Sounds like a bad rim, not totally uncommon with steelies

When the wheels were balanced were they finger balanced? makes a big difference with steel wheel.

I have a very similar setup with no issues - dynamic rims instead of kings but tyre shop said both are basically the same when i got them.
 

discomatt

Well-Known Member
#4
I spent ages trying to track down savage steering shake after putting Superior Engineering super flex arms on, replaced nearly everything and only made it slightly better or worse depending on what was replaced. Had it almost gone but still there and really annoying. I pulled off the panard rod to replace it with a heavy duty adjustable one, which never ended up being fitted but thats another story, and found the bolts had worn grooves in them which gave an extra .5mm movement, replaced the bolts and praise the Lord all shimmy gone.
The old girl now has about 400,000 km on it so probably not your issue being a relatively new car.
 

Tink

Well-Known Member
#5
Either something is loose or one of the Kings rims is out of whack.
First thing, swap back to old rims and tyres as you have already considered.
Next, check every nut and bold under the front end.
Have you done a wheel alignment?
Did you change offsets?
Have you pulled the front bearings and checked them for wear?
Good luck and keep us informed.
Tink
 
#6
Thanks everybody for the speedy replies. I agree, the dampener is likely to hide a more serious issue. I'm not sure what balancing method the tyre mob used, but it's something I'll ask them - I had no idea what finger balancing was until I googled it.

The steering components all seem to be okay, though I haven't checked the panhard rod - I'll check that out tomorrow, cheers for the idea.

I'll see how things feel with the GXL rims tomorrow; after that I'll be going down that path, Tink, checking everything from top to bottom in case it's a bad bush or something somewhere.

I have not done a wheel alignment yet, which is something I'll add to the list, though it's something I can't do myself. The front bearings are both okay as far as I can tell, though I only took the front-left apart as I could feel some slack in it; the front-right feels fine but if I can't figure this out, it's something I'll do further down the track.

I haven't changed offsets for testing purposes as the rears would protrude a bit too much on the front, though I have rotated 3 tyres through the front end (original front and left, and the spare which is also a 0 offset).

Thanks everyone for the responses! I'll certainly update this thread as try to figure this out.

Cheers
 

phs

Well-Known Member
#7
chances are it's rim or balancing related

And just because you went back to the same place to have them rebalanced does nt mean there balanced.

To my surprise machines vary and even more common people vary

Do some research on good place local you can get an alignment done, have them balance the wheels again as well.
 
#8
Quick update, the problem disappears with the GXL rims on the front, as expected. I'm sure it looked pretty ridiculous driving around with those on the front and the Kings on the back.

I'm currently having the wheels checked out by another mob, so we'll see how that goes.
 
#10
So as it turns out, 2 out of 5 tyres are bad. "Severe" run out (radial and lateral) that should have been picked up the first, let alone second, time around.

Speaking to the vendor, they don't believe it's possible to have missed something like that with their equipment. The rep for Michelin/BFG will be out on Monday to inspect the tyres.

Had it been one defective tyre this would have been a simple diagnosis. Two defective tyres, out of only three being usable on the front, pointed me in the direction of a mechanical issue exacerbated by the increased size and weight of the tyres.

The lesson, as usual, is that the simplest solution is usually the correct one.
 

Spooner

Well-Known Member
#11
I find that hard to believe that the tyres are to blame .
Good luck on getting refund mate.
You got a 10 year old car and cheap crappy rims with different offsets on them.
Not to mention that they are probably oversize tyres?
Without even getting a proper 4x4 wheel alignment done when you fitted them ?
 
#14
I find that hard to believe that the tyres are to blame .
Good luck on getting refund mate.
You got a 10 year old car and cheap crappy rims with different offsets on them.
Not to mention that they are probably oversize tyres?
Without even getting a proper 4x4 wheel alignment done when you fitted them ?
Rims or rubber, it's up to the vendor to deal with it; and they will, either by their own good will or by my persistence.

I'm not sure what you're getting at otherwise. It's a 10 year old car with 50k on the clock in mint condition, as I've kept it. The rims have as good a reputation as any steel rim, and the tyres are appropriately sized to both the vehicle and the wheel. Wheel alignments aren't necessary when changing tyres unless there's an indication otherwise, such as uneven wear or untrue tracking.

Let's keep ego out of this thread and leave it for solutions and problem solving.
 
#15
So the original vendor, with Michelin rep present, checked out the tyres today. 3/3 of the 0 offset tyres were out of round.

Two were reseated, resealed, and balanced within tolerance. The third was so bad it's being replaced.

A proper road test will have to wait, but it seems that the tyres were to blame, with a little help from poor fitting.

Thanks to everyone that contributed useful information once again.
 

phs

Well-Known Member
#16
So the original vendor, with Michelin rep present, checked out the tyres today. 3/3 of the 0 offset tyres were out of round.

Two were reseated, resealed, and balanced within tolerance. The third was so bad it's being replaced.

A proper road test will have to wait, but it seems that the tyres were to blame, with a little help from poor fitting.

Thanks to everyone that contributed useful information once again.
That's great it got sorted,
 

phs

Well-Known Member
#18
Wow that is surprising that Michelin tyres were faulty, would expect that from cheaper tyres but not a premium brand
I had a Nitto trail grappler with the same problem, I had it put on the back was not an issue there. Probably would not have been an issue on an IFS front either, solid front ends pick up everything
 
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