285/50/18 Rubs, Right Only

[South Hills]

Just returned from a trip to NTB and need to get some suggestions. I got the following tires:

245/45ZR-18 Dunlop SP 9000 (F)
285/50WR-18 Dunlop SP 9000 (R)

The 285's are mounted on stock rims widened by Lido. The left rear, no problem; the right rear rubs the shock about 1/2 the way up its length. Don't know why one side rubs, the other does not.

Rubs when jacked-up, rubs when on the ground. I did also make sure the air suspension was off when up, turned back on when down.

I have read all the many threads here about different fitments, the "does it or doesn't rub" exchanges, and even something about a shock adjustment. I do not think anyone has tried this specific tire, but I can tell you, at least on my MM, this size tire rubs. And only on the right side. And enough so you absolutely don't feel like driving it anywhere.

Wanted to share this bit of 411 on a 285/50/18 fitment (really lack thereof), and ask if the only option besides returning the rear tires and going with a lower aspect ratio (45) is to add spacers. If so, what size spacer?

Any advice will be appreciated. I had them put the winter tread back on, and am regrouping pending some recommendations.

Thank you in advance,

Phil

[RoyLPita]

Have you tried to cross rotate the rear tires? Is it possible that one rim may be a little too wide?

[KillJoy]

I would also suggest swapping the rears to see if the rubbing follows the Wheel / Tire, or the side of the car.

KillJoy

[Bradley G]

If you want to spend a little more, you could upgrade the rear suspension.
I read thier is more clearance with the coil overs.

[magindat]

Remove the bottom shock mount.
Use a band saw to cut the amount you see fit off of the inboard side of the pinion. Take that cut-off and place it on the outboard side of the bolt. You can move the shock inboard about 1/2" with this method.

This, of course, this about 1/2" at the bottom which only translates to about 1/8" where the tire hits. Sometimes, that's all you need.

Good luck.

[Marauder]

What about a simple spacer? I have 7/32" spacers on my rear and the rims are still hub centric and it pushes the wheels out a bit...looks more aggressive.

[magindat]

What about a simple spacer? I have 7/32" spacers on my rear and the rims are still hub centric and it pushes the wheels out a bit...looks more aggressive.

I agree.

For a safe, permanant, solution maybe accompany spacers with longer studs? 7/32's isn't that much loss, though.

[SergntMac]

If it were me, I'd be headed for the alignment rack, get a 4 wheel alignment inspection. Could be that your rear end has shifted ever so slightly.

If you can't do this, try to get under the car and measure across the car, from the center of the rear end housing to a fixed point on the frame. If you can't get under it, throw some water across a level dry level surface, and slowly drive through it. Check the tire tracks for dog-tracking?

[Warpath]

Alignment measurement will tell you if its dog tracking. The thrust angle measurement is essentially the angle between the axle and the vehicle centerline. Anything over/under +/- 0.5 deg is excessive. Although, there isn't much you can do about it.

[snowbird]

South hills,

If it can help, I have the same dimension tires on the back since last year, but Pirelli made. They are mounted on the stock rims (the safe limit according to tirerack) and they don't rub.

[KillJoy]

South hills,

If it can help, I have the same dimension tires on the back since last year, but Pirelli made. They are mounted on the stock rims (the safe limit according to tirerack) and they don't rub.

You put 285/50's on the stock rears?!?!?!

hmmmmmmmm.......

Got any pics?

KillJoy

[magindat]

You put 285/50's on the stock rears?!?!?!

hmmmmmmmm.......

Got any pics?

KillJoy

...widened by Lidio...
^^^LOOK^^^

[KillJoy]

I quoted snowbird. He said his are mounted on the stock rims.

I know SouthHills are.

KillJoy

[Vortech347]

Thats the size i'm running on the back with stock wheels. They don't rub

[SergntMac]

Wider wheels or not, 285 wide tires should not be rubbing. Worse yet, on just one side. Something is wrong, in the frame/axle/shock placement, maybe bent control arms.

[snowbird]

You put 285/50's on the stock rears?!?!?!

hmmmmmmmm.......

Got any pics?

KillJoy
PM sent ! (not to jack this gentleman tread)

[South Hills]

Gentlemen:

Thanks for the ideas and comments; all are good points, well made. I am thinking about this and it may be that the problem here has as its root cause an accident my MM was in a year ago January. You may recall my story about the L/M mechanic wrecking my car while driving it on a state required road test subsequent to an annual inspection. Slammed it into a guardrail while accelerating; so happens the right side of the car was hit, tip to tail, and the right rear wheel had to be replaced (rim gouge). Claimed to have encountered the dreaded black ice.

I have an appointment with the body shop that did the repairs on Wednesday. I have asked them to diagnose the problem. Seems like there must be an underlying issue that wheels spacers and shock adjustments would only serve to mask not fix.

Likely there is something a bit out of spec from this accident, although a four wheel alignment inspection was done as part of the post-accident repair and was on-spec, reportedly. I do have the Metco Control arms (I’d guess a non-factor) on the car and I have not seen any unusual wear on the tires post accident. Could be a nominal spec-out deal here exposed by the additional rubber.

Any ideas as to specific potential causes I should high-light to the body shop owner, adding in the information about the right-side hit? I assume they will make it right, whatever it is, as they do an excellent job of standing behind their work quality.

I am also glad to know others are using this tire size with out problem; helps make the case that mine has an undiscovered/unfixed problem.

I will also say that for the 10 minutes these tires where on the car (all stationary), they really look awesome; the 285/50 really fills up the wheel well (its overall diameter is + .61 stock and its section width +1.57) and it adds to the rake when set-up with the 245/45's in the front. I am hoping I can get this fixed and the tires will be a go. I will let you all know how this turns out.


Thanks again for the suggestions, thoughts and comments.

[Warpath]

If you still have the stock Watts link on, have them check it to make sure its not bent. If the RH wheel was gouged, its possible that there was enough force applied to the wheel to bend one or both of the Watts link arms. Doing so would shift the axle to the left and rub the right wheel on the frame or shock.

[Black Mac]

Has any of you replaced your tires with something different than OEMs on the the stock rims, I'm looking for a front and rear match maybe 255/55-18 rear and still use a 235/50-18 for the front any givers

Joe

[South Hills]

Warpath: If you still have the stock Watts link on, have them check it to make sure its not bent. If the RH wheel was gouged, its possible that there was enough force applied to the wheel to bend one or both of the Watts link arms. Doing so would shift the axle to the left and rub the right wheel on the frame or shock.

Thank you for this idea; I do still have the stock Watts Link; I will have the body shop check this.

SergntMac: If it were me, I'd be headed for the alignment rack, get a 4 wheel alignment inspection. Could be that your rear end has shifted ever so slightly.

If you can't do this, try to get under the car and measure across the car, from the center of the rear end housing to a fixed point on the frame. If you can't get under it, throw some water across a level dry level surface, and slowly drive through it. Check the tire tracks for dog-tracking?

Good call here; I did something a bit different, but I think it begins to get at the underlying issue here of the right-tire only rubbing the shock.

I took a level, centered on the cap, and held true perpendicular per the bubble, and measured the distance between the most outboard-point on the tire and the wheel well.

1/2" on the left side, 1 1/4" on the right. After knowing this, you can also see the difference visually when standing at the left and right rear of the car.

For all, besides the Watts Link, what else might be causing this shift to the left?

Thank you.

[Warpath]

The Watts link locates the axle left to right in the vehicle. I think its the most likely cause. If its OK, the Watts link attachments are messed up. But, I seriously doubt it. The next most likely cause is the axle is bent if its rubbing the shock which is another doubtful cause. It could be that there is nothing wrong with your MM. It could be that everything on your vehicle happens to be stacked up in the wrong direction and you just got unlucky.

[jimlam56]

Thats the size i'm running on the back with stock wheels. They don't rub
Pictures please.