Rear Flare Rubbing on Tire

[mark928gt]

Hello everyone. I'm new to the forum. I bought a project car that has wheel flares already installed. I won't go into the whole long story about the car. Bottom line is that with the coil overs adjusted equally on both sides of the rear the DS flare hits the tire but it does not on the PS. I've measured the frame to see if it is twisted. I do not believe the frame is twisted. Checking the bodywork I find that the DS flare is mounted about a 1/2 lower on the DS. Right now I have to adjust the coil over up about 2 inches on the DS to get a similar tire/flare gap as on the PS. It seems to me there must be something else going on beside the difference in bodywork that could cause me to have to adjust the suspension so much on that side. I did take the suspension out and measured springs, perches, struts, housing, etc. make sure all the suspension pieces were the same. I have not take off the control arms or other major parts to measure although I see nothing that is bent. Any suggestions on where to look next? Thanks for the help. 

[LLave]

My DS rear quarter is different than my passenger. No evidence mine was ever replaced, but the wheel well opening is 3/8" off from the PS side. I have a feeling it was build "close enough" from the factory. 

[mark928gt]

3 hours ago, LLave said:

My DS rear quarter is different than my passenger. No evidence mine was ever replaced, but the wheel well opening is 3/8" off from the PS side. I have a feeling it was build "close enough" from the factory. 

Wow. That's interesting. My flares were definitely added by the PO. I ordered a laser measurement device today so I can more accurately measure the frame in different places. Then I think I am going to just start taking everything off the back end and measuring them. 

[BrandenZ]

I too have ~1/4" clearance difference between the DS and PS with no evidence of prior collision in the rear. The easiest fix is probably going to  be to pull the DS flare and mount it 1/2" higher to match the PS. Another option may be to get wheels with a different backspacing (less positive), pushing them more inboard so they'll clear the flares. The cleanest, hardest, and most expensive option would be to ditch the flares and go with a kit (like what Ztrix offers). 🤪

 

[NewZed]

My 76 had about 1/2" smaller gap on the passenger side.  Not sure why.  Tokico lowering springs on the back, cut Nissan springs up front.  The front was the same on both sides.  I shimmed the strut studs to get rid of most of it.

 

People should say less or more, by side, instead of different.  We might see something consistent.

Edited March 5, 2020 by NewZed

[mark928gt]

Interesting that people see such a difference between the sides with stock fenders. In my case removing the flares is a huge deal because they are fiberglassed in.  I think I will take everything off of the rear end and measure each component to make sure something is not bent or put together differently. I know the coilovers were not installed correctly but they do seem to be the same from side to side. I made a cardboard template of the inside of the flare and then measured seven different points on the template. I then switched the template to the other side to make sure the flares were the same shape and to measure the location of the flare. Roughly the same shape although the DS flare appears it was pulled down a little in the middle and that is most of my side-to-side difference. Seems strange but the bottoms of the flares are in roughly the same location on each side and the top seems to be off. However that happens. I like the idea of maybe leaving the flare alone and changing the wheels to a different offset to make sure it clears. This should be done regardless probably. 

 

[BrandenZ]

Wow! I just assumed you had the usual bolted on flares. That is indeed quite the conundrum. It looks like great work too, I also wouldn't want to touch it. One other possibility is, if your struts are sectioned (likely with coilovers), that they're sectioned at uneven lengths. Either way if so, that just confirms your issue but doesn't solve it. Ignoring the wheel gap and coilover adjusted length, have you measured the distance from ground to pinch weld on both sides? This is what you should be going by, as cross weight likely is not 50/50.

 

Where is your rubbing / interference occurring and under what driving conditions? Do you have wheel spacers installed at the rear? Do you believe moving the tires inboard more, or adding more negative camber could be enough? What are the rims, tires, and associated offsets? If it's super close, you may also be able to simply swap tires. There's a surprisingly large variance of track width across different brands.

 

PS upvote because chewy.com  

Edited March 6, 2020 by BrandenZ

[NewZed]

I would find a level surface, and some good reference points on the car body, and see if the car is tilted or the flares are one the car incorrectly.  Or if something else is going on.

 

Reference points might be something obvious like the back bumper, or the bumper mounting points.  Or the inner wheel well arches.  Or the sub-frame mounting points for the suspension.

 

If the car boy is tilted,then adjusting the suspension is reasonable,and will bring the body back in to line.  If the flares are off, then adjusting the car body will introduce other weirdness, like a tilted look from the back.  

[mark928gt]

Thanks guys. It's good to talk through it with somebody else. 

8 hours ago, BrandenZ said:

Wow! I just assumed you had the usual bolted on flares. That is indeed quite the conundrum. It looks like great work too, I also wouldn't want to touch it. One other possibility is, if your struts are sectioned (likely with coilovers), that they're sectioned at uneven lengths. Either way if so, that just confirms your issue but doesn't solve it. Ignoring the wheel gap and coilover adjusted length, have you measured the distance from ground to pinch weld on both sides? This is what you should be going by, as cross weight likely is not 50/50.

 

Where is your rubbing / interference occurring and under what driving conditions? Do you have wheel spacers installed at the rear? Do you believe moving the tires inboard more, or adding more negative camber could be enough? What are the rims, tires, and associated offsets? If it's super close, you may also be able to simply swap tires. There's a surprisingly large variance of track width across different brands.

 

PS upvote because chewy.com  

Branden and NewZed. I have the car supported on four identical jack stands on my garage floor at the same locations on each side. The floor is level. I have measured from the control arm mounting points on each side down to the floor. It seems to be the same but I have ordered a laser measurement tool to get better measurements. Where is the pinch weld? 

 

The rubbing occurs just on the outside of the tire. I think you are right that a different tire or offset wheel would take care of the rubbing. The wheels are 17" Rota wheels. Not sure of the model or offset. I'll measure. I'm mainly concerned about having to adjust the suspension so different at different corners. I'll measure the strut sectioning again to make sure it is the same. 

 

BTW. I say the flares are off because when I measure from the rain gutter (non modified part of the car) down to the flare opening I have about a 1/2" difference. 

 

Thanks again for the help guys!

 

[BrandenZ]

I would highly encourage you to read the thread here:

 

What you should really do is:

- Set desired ride height, front and back and side-to-side (measuring with car on the ground)

- Have the car corner balanced (optional for tracking/racing)

- Have the car aligned as desired

 

Of course, you want this done without any rubbing or clearance issues. In my case, I had to go with less positive caster than I would've liked to clear the front air dam. In your case...

Do you have the last known good alignment specs?

What's the tire brand, make, and size on both the front and the rear (same tread profile F/R)?

Are there any wheel spacers installed in the rear?

Do you have the ability to adjust rear camber?

Can you trim the inside of the flare or the lip based on your point of contact?

 

My guess is that you do have variance side to side on how the flare is installed. However first you need to set desired rear ride height correctly, not going by wheel gap or coilover threads. That alone may do the trick. If not, you may also be able to dial in more negative camber on the rear and/or do some trimming.