That's interesting, I throw my hat at you for doing this. I suspect that my rear axle needs the same alignment method. I should ask an alignment shop I know in town. Hyundai will tell me that my car is within specs.

 

Hyundai will tell me that my car is within specs.

Yes they all do that.
As an example I also have an 05 BF Falcon that used to scrub the inside right front from new, it would always wear out in half the time of the other three.

Ford Dealers said that was standard for that car,, so I said fix it so it doesn't do it. They said we can probably make it a little better with an extreme wheel alignment.
They did this & charged me $200 & it made no difference to the right wheel but it did make the left wheel start scrubbing out the same way.

So I took it to suspension a specialist & he said that when these cars where originally drawn up, the front suspension was designed & based on a northern Hemisphere left hand drive floor plan.
The Aussie Ford factory then redesigns the body, interior etc to suit the Aussie consumer & then builds these pigs on the same left hand drive floor plan, but as righthand drive vehicles.
He said that the best way to describe what you need to do to get them to drive straight is to reverse everything to suit our cambered roads.
So that is what he did & shimmed the **** out of it & now it drives perfectly with no scrubbing.

 

I decreased the front toe in by adjusting the right front tie rod length, rotating the adjustment 60 degrees. The steering wheel now appears about centered and should be about where it was before the previous shop adjustment. I also added a 0.003” shim to the right rear hub. I then took the Elantra to a third alignment shop for an alignment check. See Alignment 2-4.

Looking at the results, I see that I have a problem. Comparing these results with the previous results:
1. The left and right toe in for the front are identical, even though I decreased the toe in and the steering wheel position confirms it.
2. The right rear toe in shows a decrease from 0.15 degree to 0.10 degree as expected, but the left rear shows an increase from 0.05 to 0.20 which is puzzling. The total toe for the rear increased from 0.20 degree to 0.30 degree with the addition of the 0.003” shim.

At this point I need to step back and think about what is going on. As an Engineer, I am used to dealing with calibrated measurements with calculated uncertainty factors. I blindly assumed that I could get an alignment check at one shop, trust those readings, make my adjustments and go to a different shop and trust those readings.

Here are some issues as I see it:
1. All these shops used computerized alignment. Is there any variation with the skill of the operator?
2. When was the last calibration performed on the alignment equipment?
3. Is there a quick check performed to verify that the alignment is still good?
4. The resolution of the Caster on the print out is 0.1 degrees, what is the accuracy?
5. The resolution of the Toe on the print out is 0.05 degrees, what is the accuracy?
6. How repeatable are the results?
7. What is the variation from shop to shop?

I now suspect that my initial calculations may have under estimated the required shim thickness for the rear hub. This first calculation provides an initial shim thickness which when installed, provides a first guess. Alignment measurements are repeated and the shim thickness is adjusted. This process is repeated until the alignment is acceptable.

 

sbr711 is our local tech guru. Especially when it comes to alignments. If he gets a chance to see your figures and read this post, he'll surely have some remarks that might help you with this.

Regarding operator skill variables: I would say, yes. I did a test once in a calibration lab. Provided a micrometer standard (calibrated to NIST) to two different machine operators and asked both to give me a measurement reading on a gauge block (also certified). Although they both came close, neither were spot-on exact nor any of their two measurements identical.

But we're not talking about building the next lunar module rocket engine. It's just an alignment, yes? No, it's not JUST an alignment. For OCD people like me, it matters. :laughing:

Besides, tires cost money. While I am not that concerned with my daily/weekly MPG's, I am not thrilled with the prospect of going to the tire store every so many thousands of miles because my car's rear alignment can't be adjusted and prematurely wears out the tread. So, my only line of defense (at this time) is tire pressure vigilance, routine rotations, & wheel balance.

 

Too bad you have to do this yourself - Hyundai should have come op with a solution by now. This version of the Elantra is now 3 years old. My current set of tires will be down to the tread wear indicators at 18K miles.

 

Have you had your alignment checked? I would really be interested to know what the numbers are, considering your poor mileage. The Hyundai dealer will check the alignment for free if you complain about poor tire mileage. Many other tire shops will also do a free alignment check. Post your results.

 

I have had several alignments - the last one shown below. On a previous alignment they shifted the axle from about equally bad on both sides in the back to good on the left and rediculous on the right.

 

Your total Toe in the rear is similiar to mine before I added the shims. Adding a shim to the right rear hub would reduce the rear Toe in. However, my tires without the shims definately lasted longer than yours.

 

Man, wish there was a way to just turn in a set of specs and say align it to this.
Another complication is if the tires are rotated every 5K miles, won't it be somewhat difficult to narrow down tread wear pattern locations without having to get alignment specs to compare with? Even then it's still somewhat a guess especially with non-directional tires.
I have free oil changes and rotations every 5K miles as long as I have the car, so I'm not going to pass on that.

 

The front end numbers on my vehicle look good for camber, castor and toe in. With the shims, I can also adjust the rear toe in and also if needed, rear camber. My question is what are the best rear toe in and rear camber settings for the Elantra?

 

My guess is that you are in good shape in the rear. I doubt anyone will suggest an optimum alignment. If you want to tweek some more you might consider getting the left toe down to 0.1 also.

 

Conclusions

After doing additional research, which confirmed my desire reduce to the rear toe to near zero, I placed six 0.003” shim layers for a total of 0.018” on both rear hubs. At this time, I decided to not adjust the rear camber, although this could result in increased inside tire wear. A good source of info on tires and alignment is CapriRacer’s web site: Barry’s Tire Tech http://www.barrystiretech.com/alignmentrecommendation.html . Due to the inconsistency in results between alignment shops, I had my alignment checked at two additional shops. Maybe I should have gone for the best two out of three. See attached results.

Observations:
1. The results at Greulichs look reasonable. The Firestone toe results look strange. Total toe measurements were similar for both shops.
2. I observed that during the Firestone alignment, the Elantra was angled a little to the left on the rack. Don’t know if this would affect the results.
3. Both shops used the same Hunter computerized alignment equipment.
4. I asked both shops when the last calibration was performed on the equipment. They both thought in the last 6 months, but were not sure. They commented that there was an annual update.
5. I asked if any verification checks of the alignment system were performed. They both looked confused and stated that the system was accurate.

Final Conclusions:
1. Be careful which alignment shop you use. Check around to see which one has a good reputation. Of the five shops I used, only the Hyundai dealer and Greulichs provided results that I am comfortable with.
2. Camber and Castor measurements were reasonably consistent at all shops. Toe measurements varied from shop to shop.
3. The only easy adjustment on the Elantra is front Toe. Going to a random alignment shop will result in hit or miss front Toe adjustment.
4. Total rear toe was reduced from 0.55 degrees to 0.06 degrees with the use of two 0.018” shims.
5. My adjusted formula for estimating shim thickness is: Thickness = TAN degree * 4.2
6. My Elantra handles well and I should get excellent tire wear.

So how does this apply to other Elantra owners?
1. This was my first attempt at adjusting alignment. The process was enjoyable for me, but did take some time for the research and initial work. The last change took me about 15 minutes to make the two additional shims and 30 minutes to install the shims on both sides. Getting the free alignment checks took about 1 hour each.
2. One would need to get an alignment check at a Hyundai dealer or other reputable alignment shop. Using the rear toe measurement, the thickness of the shim for each side would be calculated. Make the 3” by 1” shims and install on each side. Repeat the alignment check to verify the new rear toe.
3. At this point the results may be close enough. This should definitely reduce the rear tire wear.

 

After doing additional research, which confirmed my desire reduce to the rear toe to near zero, I placed six 0.003” shim layers for a total of 0.018” on both rear hubs. At this time, I decided to not adjust the rear camber, although this could result in increased inside tire wear. A good source of info on tires and alignment is CapriRacer’s web site: Barry’s Tire Tech http://www.barrystiretech.com/alignmentrecommendation.html . Due to the inconsistency in results between alignment shops, I had my alignment checked at two additional shops. Maybe I should have gone for the best two out of three. See attached results.

Observations:
1. The results at Greulichs look reasonable. The Firestone toe results look strange. Total toe measurements were similar for both shops.
2. I observed that during the Firestone alignment, the Elantra was angled a little to the left on the rack. Don’t know if this would affect the results.
3. Both shops used the same Hunter computerized alignment equipment.
4. I asked both shops when the last calibration was performed on the equipment. They both thought in the last 6 months, but were not sure. They commented that there was an annual update.
5. I asked if any verification checks of the alignment system were performed. They both looked confused and stated that the system was accurate.

Final Conclusions:
1. Be careful which alignment shop you use. Check around to see which one has a good reputation. Of the five shops I used, only the Hyundai dealer and Greulichs provided results that I am comfortable with.
2. Camber and Castor measurements were reasonably consistent at all shops. Toe measurements varied from shop to shop.
3. The only easy adjustment on the Elantra is front Toe. Going to a random alignment shop will result in hit or miss front Toe adjustment.
4. Total rear toe was reduced from 0.55 degrees to 0.06 degrees with the use of two 0.018” shims.
5. My adjusted formula for estimating shim thickness is: Thickness = TAN degree * 4.2
6. My Elantra handles well and I should get excellent tire wear.

So how does this apply to other Elantra owners?
1. This was my first attempt at adjusting alignment. The process was enjoyable for me, but did take some time for the research and initial work. The last change took me about 15 minutes to make the two additional shims and 30 minutes to install the shims on both sides. Getting the free alignment checks took about 1 hour each.
2. One would need to get an alignment check at a Hyundai dealer or other reputable alignment shop. Using the rear toe measurement, the thickness of the shim for each side would be calculated. Make the 3” by 1” shims and install on each side. Repeat the alignment check to verify the new rear toe.
3. At this point the results may be close enough. This should definitely reduce the rear tire wear.

What for the life of me is 'steer-ahead'? No
satisfactory explanation can be found on
line or from any alignment place I've asked.

smh*

*SCRATCHING my head!

 

Nice write up and great effort. Thanks

Though the proof is what happens with tire wear and if you have any negative side effect on brake wear. Please update when appropriate.

 

You might want to check the disk brake clearences pad to rotor after your alignment tweek. If they are off too much you might want to shim the caliper assembly as well.

 

You might want to check the disk brake clearences pad to rotor after your alignment tweek. If they are off too much you might want to shim the caliper assembly as well.

My disclaimer - I am not a mechanic so do the above at your own risk.

 

The toe was adjusted out by 0.25 degree on each side. This results in less than 1/100 of an inch difference over the width of the brake pad. My brake pads tend to last a long time, but I will monitor the wear.

 

Just to let you know. your local car part does have a part number for the shim on the elantra, it cost around 20$, and come with a chart that tell you ln what direction to put it and what it will affect.
Also it should have been but behind that backplate, so the caliper and disc would still be lign up perfectly

I charge around 200$ for all wheel, with 2 shim install, for an alignment at my job

 

Just to let you know. your local car part does have a part number for the shim on the elantra, it cost around 20$, and come with a chart that tell you ln what direction to put it and what it will affect.
Also it should have been but behind that backplate, so the caliper and disc would still be lign up perfectly

I charge around 200$ for all wheel, with 2 shim install, for an alignment at my job

Specialty Products 75800?

 

The plastic composite shims are another way to adjust the rear Toe and Camber. I preferred to use a metal shim. Mounting the shim behind the back plate would have the same effect on the caliper to disc alignment, since the caliper is mounted to the axle.

 

Reasons for adjusting the rear alignment

Reasons for adjusting the rear alignment.
1. There is a difference between the left rear and right rear alignment readings that is causing a handling issue.
2. Rear tire wear caused by rear toe in.
3. Desire to change rear camber settings.

What are the effects of reducing the rear toe setting?
1. Reduced rear tire wear.
2. Increased oversteer.

From a post by only1db in the veloster alignment forum:

what happens is when you point the wheels in the rear toward the inner portion of the car / \ the rear tires will want to go IN. When you toe the rear out | | the rear tires will follow the path of the front tires. This will end up with the rear of the car rotating around and when pushed will induce oversteer. Hyundai intentionally puts toe in...in the rear to help with the oversteer. People are more apt for dealing with understeer then oversteer. Especially in a FWD car.

We can NOT fix the alignment without some modifications to the suspension as noted before by placing shims behind the bearing assembly or some other mod.

the argument here is that one person thinks it is excessive amount while me and others thinks that while not ideal...it is acceptable and other manufactures do the same thing...not just Hyundai.

 

Reasons for adjusting the rear alignment.
1. There is a difference between the left rear and right rear alignment readings that is causing a handling issue.
2. Rear tire wear caused by rear toe in.
3. Desire to change rear camber settings.

What are the effects of reducing the rear toe setting?
1. Reduced rear tire wear.
2. Increased oversteer.

From a post by only1db in the veloster alignment forum:

what happens is when you point the wheels in the rear toward the inner portion of the car / \ the rear tires will want to go IN. When you toe the rear out | | the rear tires will follow the path of the front tires. This will end up with the rear of the car rotating around and when pushed will induce oversteer. Hyundai intentionally puts toe in...in the rear to help with the oversteer. People are more apt for dealing with understeer then oversteer. Especially in a FWD car.

We can NOT fix the alignment without some modifications to the suspension as noted before by placing shims behind the bearing assembly or some other mod.

the argument here is that one person thinks it is excessive amount while me and others thinks that while not ideal...it is acceptable and other manufactures do the same thing...not just Hyundai.

I think he is basically correct.

Stock settings are usually a compromise between handling performance and tire wear. If you notice stock tolerances do allow a tiny bit more rear toe-in. These tolerances are for the car's stock bushings and common suspension flex in normal driving.

Any change from stock for any kind of improvement has to be evaluated over time for any desired and/or negative results. And the results will be affected by many different conditions such as driving style and tire air pressure. Not to mention that if starting off from out of spec to preferred spec will make a big improvement in both handling and wear. But then manufacturer should replace the defective suspension parts.

 

8,500 Mile Update

Its been 8,500 miles since I added shims to the rear hubs of my Elantra. After I added the shims, I carefully measured the tread depth on the Hankook Optima H426 tires at the four grooves on each tire using the depth gage of a dial caliper. I just repeated the measurement when I rotated the tires at 45,700 miles. It is difficult to get repeatible results, since the tread depth varies along the circumference of the tire. Repeating the measurements at my next rotation in 10K miles should give a more accurate reading on tire wear.

The overall average tread wear over 8.5K miles for the front tires was 1/2 of a 32nd of an inch. The rear tire wear was 1/6 of a 32nd of an inch. These results seem low, and imply that I should get another 40K miles on these tires. My next measurements in 10K miles will provide a better estimate. The insides of the rear tires are now wearing faster than the outside.

The handling is good. It corners well. I checked the rear brakes. There is little additional wear, although most of the miles are highway miles.

 

The entire thread is fascinating. Keep us posted at 10K.

 

8500 Mile Thoughts

Based on my 8500 miles results with shims installed, the following are my thoughts:

1. The Elantra frontend has adjustable toe and camber that can be adjusted with cam bolts or camberplates.

2. If the front end is near the center of Hyundai specs, the front tires should last as long as tires on other front wheel drive vehicles that are in alignment.

3. The Elantra rear end has no easy adjustments. Axle shims can be installed to adjust for toe and camber.

4. If the rear end is near the center of Hyundai specs, the rear tires will wear perhaps twice as fast as the front tires due to toe and camber.

5. Reducing the rear toe to near zero will result in rear tire mileage similar to the rear tire mileage of other front wheel drive vehicles that are in alignment.

6. The OEM HankookOptimo H426 tires are noisy and have poor winter traction. However, the short tread life is due to the Hyundai design of the Elantra rear axle.

7. Unless alignment changes are made to the Elantra rear axle to reduce the toe, replacement tire tread life is likely to also be short.

8. I recommend checking the alignment on your Elantra to determine where it is set. The rear toe will give you an estimate of how long your tires will last.

 

Just returned from having new tires installed and an alignment. My car is lowered on Eibachs and I have Veloster Koni inserts with Veloster struts. I purchased ±1.75°. cam bolts. I asked for a printout and was told that they could snap a pic with a phone. Ok I said. They couldn't get the left front camber in spec with the bolts so they "didn't bother to take the pic." I'm done with that shop. Another alignment place bites the dust with me. I did see the machine and my rear toe is .39 left and .49 right. Ugghh. I got 90K mi. on the tires I just replaced, Goodyear Fuelmax. The car has been lowered for 12K and the wear is not too bad. I am going to get ±2.25° cam bolts, Rockauto will take my others back. I am going to let my son take the car to his work place and check and adjust front camber. I am going to shim the rear. I have to further study to calculate thickness for each side. I program a turret and laser at work and I think we have some laminated material around that may work, probably burn some shims on the laser. Any suggestions for thickness to start with appreciated.

 

For rear use Northstar Manufacturing .25 Degrees Rear Camber/Toe Shim (Burgandy)
Part # 46-1301 SKU: 8475464
Can buy from Pepboys

Check on manual I mark on degree L & R

 

My total rear toe was reduced from 0.55 degrees to 0.06 degrees with the use of one 0.018” shim on each side. Thus 0.018" shim adjusted each side by .25 degree.

My estimate, assuming you want zero toe, 0.018 / .25 * .39 = 0.028", 0.018 / .25 * .49 = 0.035"

My adjusted formula for estimating shim thickness is: Thickness = 4.2 * TAN degree

4.2 * Tan .39 = 0.028"
4.2 * Tan .49 = 0.036"

 

Thanks wblanford, I found your equation and agree with your math (I rounded up to .029) Did you use 3.5" dimension for the hole center distance for the pins, and the center hole is Ø2.9" Thanks

 

My original calculation, see first post in this thread:

What I wanted to determine is what thickness of shims on the two sides would be needed to reduce the toe in to near zero. I made a tracing of the flange and measured the bolt spacings, see Hub Dimentions photo:
1. 3.5” between upper bolts
2. 3.3” between lower bolts
3. 2” between upper and bolts
4. There is also a 0.25” guide pin on each side.
5. The center opening for the bearing is 2.9”

I decided to use a 3” long by 1” wide shim. In order to calculate the required shim thickness, I reviewed some high school geometry:
TAN angle = opposite side / adjacent side
TAN angle = thickness / bolt spacing
Thickness = TAN angle * bolt spacing
I used 3” for bolt spacing since I was not sure where the pivot point would be for the hub with the shim. I wanted to reduce the total toe in from 0.55 degree to 0.05 degree so I used 0.25 degree for each side.
Thickness = TAN 0.25 * 3”
Thickness = 0.013”

However, this estimate resulted in too thin a shim. I therefore adjusted the formula to reflect my actual results.

I now recommend: Thickness = 4.2 * TAN degree

 

schulykill "I got 90K mi. on the tires I just replaced, Goodyear Fuelmax. "

That was great tire mileage on those tires. Did you happen to get any alignment readings prior to lowering your Elantra? Also, which OEM tires, what mileage and what tread depth did you get on your original tires?

What tire pressure do you maintain? Any other thoughts on how to get such great tire life?