Rear Camber & Tire Wear

[jmettee]

I know our cars come from the factory with such great suspensions designs that we can only adjust toe on the front & rear...so we're stuck with our existing caster & camber on the stock setup. However, I'm wondering if the values for other cars are as far off as my car is or if I just have a unique example.

The attached alignment sheet done on my car @ 45K show all values within reason EXCEPT for rear camber (the RR tow should be closer than shown as I installed 1 more shim when I got home after the alignment). The specified range is -.75º to -.25º...mine is about -1.70º on both wheels. Due to the different, the attached photo of my rear tire tread is what happens after 8K of driving. The inside shoulder of the tire is almost smooth. Seems like the only answer is to install a set of adjustable lower links.

Is this much of a camber difference seen in ALL cars, or do I have a unique situation somehow? Since most all values are within reason, & both rear cambers are almost the same, it would seem to me that my car's frame is not twisted or out of whack, but the tires are just not made to run with that poor of an alignment!
25522553

[Ozzie]

Are you sure your rear suspension was not lowered from stock, previously?

If so, what you are showing, I have seen the same with lowered cars that have not had adjustable links installed at the same time.

I know you know this, but it bears repeating for others who may not, the geometry of the hub changes when the rear suspension is lowered and as such, there is no way for the stock setup to be re-adjusted for a proper camber.

Edit: Are the springs stock, i.e, same number of coils and overall height?

[Patrick C]

http://www.midstatedmc.com/parts/adjarm.html

These are wonderful.

[jmettee]

Is you sure your rear suspension was not lowered from stock, previously?

If so, what you are showing, I have seen the same with lowered cars that have not had adjustable links installed at the same time.

I know you know this, but it bears repeating for others who may not, the geometry of the hub changes when the rear suspension is lowered and as such, there is no way for the stock setup to be re-adjusted for a proper camber.

I have Marty Maier's shock setup, which you can partially see in the picture. He set the collar to stock height & judging from the rear wheel gap, it is close to stock. Here's the most recent picture that you can see the rear gap. I don't have a straight shot of the side right now. My alignment was done after the shocks were installed (over a year ago) & the picture below is from last fall.
2558

[dhaney]

http://www.midstatedmc.com/parts/adjarm.html

These are wonderful.

What I would do is order some brand new bushings and have them pressed in then send the new arms to Marty and have them made into adjustable arms.

I agree these are a great upgrade, my alignment guy loves them and was able to put my car into 100% spec with them.

Dan

[jmettee]

What I would do is order some brand new bushings and have them pressed in then send the new arms to Marty and have them made into adjustable arms.

I agree these are a great upgrade, my alignment guy loves them and was able to put my car into 100% spec with them.

Dan

Yep, they are in the plans. Just wondering is many/all stock DMCs have this significant issue or if I am in a minority.

[David T]

Rear camber is only a problem if the car is lowered or something is bent. Front caster and camber is adjustable, just not easily. You have to drill out the rivets and reposition the ball joints. Should never have to be done under "normal" circumstances.
David Teitelbaum

[DMCMW Dave]

What I would do is order some brand new bushings and have them pressed in then send the new arms to Marty and have them made into adjustable arms.

I agree these are a great upgrade, my alignment guy loves them and was able to put my car into 100% spec with them.

Dan

I usually keep in local stock a set of "Marty Arms" made from new arms with NOS bushings in them if you don't want to mess with having your car off the ground waiting for the mod. You can keep your old ones. A very slight premium over buying a set of new arms and mailing them to Marty.

[stevedmc]

This is what I don't understand about DMCH's suspension kit. It includes lowered eibach springs all the way around but doesn't really take into consideration messing up rear alignment when you replace the rear springs.

[content22207]

... Front caster and camber is adjustable, just not easily. You have to drill out the rivets and reposition the ball joints....

You can decrease front caster (negative) by inserting washers between the sway bar bushings and the crumple extension.

Bill Robertson
#5939

[delornut]

This is what I don't understand about DMCH's suspension kit. It includes lowered eibach springs all the way around but doesn't really take into consideration messing up rear alignment when you replace the rear springs.

I've had my car lowered for about 90,000 miles and currently have the Houston Eibach set up with no significant wear, maybe just a bit more on the inside tread on the rear tires. I've said this before but some negative camber at the rear enhances handling, more so with a rear engine car.

Bruce Benson

[Rich]

Yep, they are in the plans. Just wondering is many/all stock DMCs have this significant issue or if I am in a minority.

You are not in the minority. The OEM spring/shock setup gives correct rear camber if everything is straight. As others note, dropping the rear ride height with all of the rest of the parts staying OEM results in negative camber.

The lower you go the more you'll get. It's just the suspension geometry at work and they all do it since they all have a similar geometry, setting aside production tolerances.

If you move to DMC/Spax/Marty/other rear aftermarket shocks that have the ride height adjustment collar/nut then you have options.
a. Adjust rear ride height to stock/OEM spec - then the camber will be similar to what you had with the OEM shocks. Normal tire wear.
b. Lower the rear ride height via the spring collar adjustment and either
- Swap in adjustable lower links, dialing in the camber per specs - OR
- Stick with the OEM links with the larger neg. camber and the asymmetric rear tire wear and whatever handling change comes with it

Your car is not in the minority. And the DMC-12 is not in the minority. Similar tradeoff is found in lowering many other cars, too.

[jmettee]

OK, so since I'm home for the weekend, I checked into the shock height setting. It is set within 1/8" of the OEM setup, & based on the suspension geometries, this should not make a significant difference. For reference, on the flat garage floor, it is 6-1/8" from floor to the bottom of the frame under the engine (i.e. the rear ground clearance).

[Ozzie]

You made me curious, so I went out to check on my car.
Same measurement: 6 1/4"
Same location of measurement, bottom of rear engine frame to ground.

Don't know if yours being an extra 1/8" lower would be the difference for your inside wear, but I checked both my rear tires, which have been on the car since I got it in 2006 (nearly 10K miles ago), and there is no visible inside wear relative to the outsides.

[DMC5180]

This got me thinking about the Control link bushings. Given that most are now 30 years old, it would be plausible that the bushings have taken set to their loaded positions. Also that's why Most cars have full adjustability to compensate for wear.

Example. The upper link is always under Compression so the weighted Overall length could be 1/4-3/8" less than Nominal. The lower link is in Tension creating the opposite effect by ADDING 1/4-3/8" to overall length. That might explain why a NEW part spec of .25-.75 Deg NEG is possible. Versus old part reading 1.75 Deg NEG.

[Kevin]

I was about to post this same exact problem and question. Did you ever get your rear camber sorted, Justin? Did you end up using the adjustable LCAs?

I know the front of my car has been lowered with Grady's springs, but not sure about the back. I've posted a photo (excuse the mess). You can tell even in that photo that there is obvious negative camber.

[DMCMW Dave]

I was about to post this same exact problem and question. Did you ever get your rear camber sorted, Justin? Did you end up using the adjustable LCAs?

I know the front of my car has been lowered with Grady's springs, but not sure about the back. I've posted a photo (excuse the mess). You can tell even in that photo that there is obvious negative camber.

You can get adjustable lower control arms. We sell them ready to install or you can get yours modified by Mid-States (Marty) if you don't mind leaving the car off the ground for a week or two.

[Bitsyncmaster]

I was about to post this same exact problem and question. Did you ever get your rear camber sorted, Justin? Did you end up using the adjustable LCAs?

I know the front of my car has been lowered with Grady's springs, but not sure about the back. I've posted a photo (excuse the mess). You can tell even in that photo that there is obvious negative camber.

That looks way off. Must be missing a bushing. Are both sides the same?

[Kevin]

You can get adjustable lower control arms. We sell them ready to install or you can get yours modified by Mid-States (Marty) if you don't mind leaving the car off the ground for a week or two.

Sounds great, Dave. I'll probably be contacting Julee soon.


That looks way off. Must be missing a bushing. Are both sides the same?

Yes the other side looks the same. I've posted a few more photos to try and show the angle of both wheels, you can tell the difference by comparing it to the front wheels. I included a photo viewing from the side as a reference of ride height.

Everything feels solid in the back end, and I haven't heard any strange noises, so I'm guessing all my bushings are there. It may simply be a case of lower springs, which I'm not sure if my rear springs or original or not which is why I included a photo above, and I don't have any measuring tape handy right now to measure the ride height.

[Mickfly]

I know our cars come from the factory with such great suspensions designs that we can only adjust toe on the front & rear...so we're stuck with our existing caster & camber on the stock setup. However, I'm wondering if the values for other cars are as far off as my car is or if I just have a unique example.

The attached alignment sheet done on my car @ 45K show all values within reason EXCEPT for rear camber (the RR tow should be closer than shown as I installed 1 more shim when I got home after the alignment). The specified range is -.75º to -.25º...mine is about -1.70º on both wheels. Due to the different, the attached photo of my rear tire tread is what happens after 8K of driving. The inside shoulder of the tire is almost smooth. Seems like the only answer is to install a set of adjustable lower links.

Is this much of a camber difference seen in ALL cars, or do I have a unique situation somehow? Since most all values are within reason, & both rear cambers are almost the same, it would seem to me that my car's frame is not twisted or out of whack, but the tires are just not made to run with that poor of an alignment!
25522553

I lower my car and added adjustable lower links. I have not had any problems withe the rear camber on the car. See picture.

[JAS037]

Does anyone know if adjustable control arms are still available anywhere?

[Delorean Industries]

We offer both:

http://www.deloreanindustries.com/36-top-link-arm-adjustable-pair/


http://www.deloreanindustries.com/16-adjustable-lower-control-arms-rear/

[JAS037]

We offer both:

http://www.deloreanindustries.com/36-top-link-arm-adjustable-pair/


http://www.deloreanindustries.com/16-adjustable-lower-control-arms-rear/

Great! Thank you.

[David T]

You should only need them if the car is lowered. If your camber is way off and the car is NOT lowered these adjustable rear lower arms are not meant to fix that. Usually means something is bent or badly worn. If the car IS lowered you MUST have them and properly adjusted to get good tire wear and handling.

[JAS037]

You should only need them if the car is lowered. If your camber is way off and the car is NOT lowered these adjustable rear lower arms are not meant to fix that. Usually means something is bent or badly worn. If the car IS lowered you MUST have them and properly adjusted to get good tire wear and handling.

Yes, my car is actually being lowered at the moment by DMCNW. Mike has told me that it is NOT essential that I use adjustable arms. In fact, he indicates the handling improves a bit because of the altered stance, although tire wear could be an issue. When I get the car, I'll be watching for poor tread wear on the inside. If that starts to happen, I'll get the adjustable control arms.

[Delorean Industries]

You are being improperly informed on this. With the dmch kit the camber is thrown severely out of alignment. This is not a driving advantage and will cause excessive wear very quickly. We correct this for owners who are sold this configuration regularly. I believe this is because the adjustment configuration is not something they offer and it would cause issues with the over the counter sales of their suspension package.

[JAS037]

You are being improperly informed on this. With the dmch kit the camber is thrown severely out of alignment. This is not a driving advantage and will cause excessive wear very quickly. We correct this for owners who are sold this configuration regularly. I believe this is because the adjustment configuration is not something they offer and it would cause issues with the over the counter sales of their suspension package.

Fair enough, I'll be checking with them ASAP. Thanks for you help!