What is the proper way to adjust for rims being too large? - PeachParts Mercedes-Benz Forum

spinedoc · #1 02-27-2003, 04:48 AM

I just bought my 91 500SL and it had some killer 18 inch rims on it with nice Yokohama's. The front rims rub a bit, only with large potholes or with very tight turning like U-turns. But they also are starting to rub out on the fenders themselves. This is only on the fronts as far as I can tell.

I know I can put spacers in, but I would rather fix this the proper way and not cut corners if I dont have to. What should I do? Should I look at new shocks or something else? If I do spacers should I do all 4, or just the front 2? Are there any other solutions I am missing?

The car rides quite stiff with the 18's, I dont mind it too much as the tradeoff is the handling is phenomenal. I still havent figured out what the button on my console with the tire is, Im assuming its the ADS, so maybe that will soften the ride up if I experiment with it.

Thanks guys.

Luke@tirerack · #2 02-27-2003, 08:30 AM

spacers would actually make the problem worse .... the wheels obviously do not fit the car correctly or maybe it's a simple as the wrong size tire .... you should be using a 245/40-18 size in the front

Ashman · #3 02-27-2003, 12:51 PM

I thinkt he button with the tire is winter mode. makes the car start in 2nd gear or something. not sure on that. I just know on my dad's sl600 when you turn that on the car lags on takeoff somewhat.

Alon

New2Mercedes · #4 02-28-2003, 01:00 AM

The switch is the "snow chain" switch. This button is to be depressed when you have opted to use snow chains on the car. I have not been able to find out what it technically does to benefit you but is only operational at speeds up to 25mph. I suspect Ashman is on the right track that it plays with the differential or transmission to ensure smoother acceleration.

Personally I never plan to use mine with chains so unless some Member can explain what this actually does it will remain unused on my car. I have been curious bout this for a while but none of my technical advisors at the dealer could answer.

spinedoc · #5 03-04-2003, 06:09 PM

Luke, Im actually runnning 245/40 18X8.5 on both front and rear so I am not sure what is wrong. They are rubbing against the side fenders.

Is there a smaller tire I can go with? Im not sure what to do here. I really love the wheels and would like every possible option before getting rid of them. Hopefully we can price something out that fits.

If it helps the rims are "Neeper Haas" 18 inch. The current tires on it are Kumho Ecsta supra ZR18. They are pretty worn so its not a big deal for new tires. I think I would like to check out yokohama;s, but I have to be sure they wont rub.

Thanx much for the help.

Luke@tirerack · #6 03-05-2003, 07:53 AM

245/40-18 is the correct size for your car so, it sounds like the offset is wrong. The wheels probably have an offset that is too low which causes the wheels to stick out further than they should which would allow the tires to rub on the fenders ..... do you know what offset your wheels have ?????? It should be 20mm - 25mm .... If the offset is within that range the next items to check are the suspension for possible worn and sagging springs or bad bushings allowing the control arms to move forward and backward which could also cause your rubbing.

PaulG · #7 03-05-2003, 08:54 AM

Why not get a bodyshop to relieve the areas where there's contact?

Bet it would be cheaper than new tyres and wheels.......

spinedoc · #8 03-05-2003, 01:53 PM

Luke, how do I find the offset of the rims? They are Neeper Concept rims, specifically the "Haas" ones.

The odd thing is that the left one rubs way more than the rigtht one. The right one is just starting to rub out the fender not very much, but the left one actually pulls out the fender and has lots of scarring on the tire itself.

The car just got out of the dealer, who did the 120k mile service on it. They said there were no suspension issues with the vehicle, just that the rims were the wrong size. I do get weird suspension problems , sometimes the car seems to "roll" to one side or another on uneven roads, just for a second or two.

All in all I still do need new tires so would like to price out a good set of all season yokohama's. But I guess Ihave to solve this first. Im taking it to a body shop this weekend to see about rolling out the fenders a bit, then next week I am going to have the suspension looked at again.

PaulG · #9 03-06-2003, 04:46 AM

Spinedoc,

The "roll" to one side or another on uneven roads" you mention is called "tramlining" and is a natural consequence of very wide tyres. It is normally kept to acceptable levels by carefully balancing the various aspects of the front suspension and steering geometry.

This delicate balance can be screwed-up if the offset is wrong (as Luke says). If you want the wheels to look as wide as possible, there's a price to be paid (not just in dollars).

spinedoc · #10 03-06-2003, 07:13 AM

I'm wondering if my setup has spacers. I am going to pull the tires today if the weather allows and take a look. These really are beautiful wheels and I HATE to let them go.

Can anyone venture a guess as to why only the left one rubs significantly?

spinedoc · #11 03-06-2003, 07:44 AM

OK I found out that my concept neeper Haaz wheels can be offset in either 15, 34 or 45. What is the bolt pattern on my 1991 500SL? This way I can look up exactly which rim I have and figure out the offset.

If my offset is 3 or 45 am I screwed? Any possible solutions to this?

Luke@tirerack · #12 03-06-2003, 07:52 AM

Quote:

Originally posted by spinedoc
Luke, how do I find the offset of the rims?

on the back side of the wheels you will find some writing it should be some like this

18H 8.5J ET35

this is just an example and it would mean

wheel size 18" x 8.5"
offset 35mm

all of the writing may not be in the same spot so look carefully for it because on some wheels it is very hard to find

spinedoc · #13 03-06-2003, 08:01 AM

OK by process of elimination I have found that I have the following wheel

N16688544P0A 18X8.5 5X112 Offset 15

OK so if my offset is 15 why the heck do I keep rubbing on the fenders?

Luke@tirerack · #14 03-06-2003, 09:07 AM

the 15mm offset is to low .... thats causing the wheels to stick out to far which is why you are rubbing the fender ..... there are a couple of options for your situation ... some of them you may not like and some are rather easy

#1.) get wheels that fit you car correctly
#2.) roll the fender lips up to allow for more room for the tire
#3.) get new tires because even in the same size not all tires have the same tread width so, get a narrower tire
#4.) adjustable shocks set on really stiff so the suspension won't compress

I would go with number 2 or 3

need2speed · #15 03-06-2003, 03:10 PM

Luke is being pretty optimistic...your offset is way off stock specs but the ET34 rims would be right on.

You have very little tolerance on the front of the R129 to vary from stock offset...perhaps by up to 5mm but certainly not by 19mm! I've only seen fitmets as low as ET30 recommended for an 8.5 rim width.

I think Luke's option #1 might be your eventual solution.

You can replace just the front rims if you're having no problems at the back. But ET15 is even extreme for rear rims on the R129....don't even consider lowering springs!