Steering squirrely at 50 mph and above

[apexi]

I mentioned it earlier in this thread.. but everything you guys are describing sounds like tramlining to the T. The tires want to follow any grooves, or uneven pavement in the road. If the tire suddenly hits a patch of pavement that is uneven, the car will absolutely pull in that direction with tramlining. If you're traveling on a highway and you can see two ruts in the road where tires typically travel, that's a nightmare with tramlining.

 

I'll admit I don't know much about suspensions, but I've experienced this before and understand how frustrating and sometimes scary it can be.

 

Tirerack says camber and toe can play a big role in this, I don't know what you would consider "extreme" positive or negative camber, but it looks like a poor alignment can certainly cause what you guys are experiencing.

 

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=47

 

"Using higher tire pressures than recommended by the vehicle manufacturer for your driving conditions will unnecessarily stiffen the tire and make it even more willing to cause tramlining. If you are running higher tire pressures than necessary, simply dropping the tire pressures to those recommended by the vehicle manufacturer will help reduce tramlining.

 

Alignment settings can be key as well. The "camber" and "toe" settings both play a role in vehicle stability and the propensity for tramlining. Extreme positive or negative camber settings will make a vehicle more sensitive, especially when only one wheel encounters a longitudinal rut and/or groove at a time. Even if all the tires are "aimed" straight ahead when the vehicle is in motion, a tire that is "cambered" wants to turn. This is the result of the "camber thrust" generated by a leaning tire (it is also part of the explanation of how motorcycles turn). A vehicle suspension using lots of negative camber for competition or the track will experience more tramlining on the street.

 

Additionally, the drivers who use additional toe-out settings to encourage their vehicle to turn into corners better also encourage tramlining because the extra toe-out will reduce vehicle stability in a straight line.

 

In the case of the competition driver who uses non-factory alignment settings, the amount of tramlining that is acceptable has to be left up to the driver. For only street-driven cars, getting them aligned with negative camber and toe settings within the factory's specifications is an important first step."

[OTKing]

I will find a local (Louisville KY) alignment place to align my car. What do I tell the alignment shop? "Car wanders at interstate speed and I want a 4 wheel alignment?" I also want a print out of the alignment specs for before and after alignment and also required alignment ranges - toe, camber and caster. What about measurements for cross camber or measurements that are not adjustable on our car? I want to be as specific as possible with the alignment shop.

 

I have a 2015 Legacy Limited with the wandering at highway speed problem. My car now has 21000 miles and although not as bad when new the problem still exists (after 3 dealer alignments). I am very glad to read in this forum some experts in car alignment are investigating.

 

Concerning the previous writers comments on "trammeling." According to Tire Rack my 18" Goodyear tires are slightly more than 1/2 wider (each tire) than the 17" stock tires, but according my dealer both width tires (17 inch and 18 inch) have the same alignment specs. A cause for trammeling? Has anyone with a 18 inch Legacy wheels with wandering issues switched wheels to a 17" Legacy wheel? Does it make any difference?

 

Thanks

[Beamercub]

I mentioned it earlier in this thread.. but everything you guys are describing sounds like tramlining to the T. The tires want to follow any grooves, or uneven pavement in the road. If the tire suddenly hits a patch of pavement that is uneven, the car will absolutely pull in that direction with tramlining. If you're traveling on a highway and you can see two ruts in the road where tires typically travel, that's a nightmare with tramlining.

 

I'll admit I don't know much about suspensions, but I've experienced this before and understand how frustrating and sometimes scary it can be.

 

Tirerack says camber and toe can play a big role in this, I don't know what you would consider "extreme" positive or negative camber, but it looks like a poor alignment can certainly cause what you guys are experiencing.

 

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=47

 

"Using higher tire pressures than recommended by the vehicle manufacturer for your driving conditions will unnecessarily stiffen the tire and make it even more willing to cause tramlining. If you are running higher tire pressures than necessary, simply dropping the tire pressures to those recommended by the vehicle manufacturer will help reduce tramlining.

 

Alignment settings can be key as well. The "camber" and "toe" settings both play a role in vehicle stability and the propensity for tramlining. Extreme positive or negative camber settings will make a vehicle more sensitive, especially when only one wheel encounters a longitudinal rut and/or groove at a time. Even if all the tires are "aimed" straight ahead when the vehicle is in motion, a tire that is "cambered" wants to turn. This is the result of the "camber thrust" generated by a leaning tire (it is also part of the explanation of how motorcycles turn). A vehicle suspension using lots of negative camber for competition or the track will experience more tramlining on the street.

 

Additionally, the drivers who use additional toe-out settings to encourage their vehicle to turn into corners better also encourage tramlining because the extra toe-out will reduce vehicle stability in a straight line.

 

In the case of the competition driver who uses non-factory alignment settings, the amount of tramlining that is acceptable has to be left up to the driver. For only street-driven cars, getting them aligned with negative camber and toe settings within the factory's specifications is an important first step."

 

---I wish it was something as something as simple as you mentioned in your post.. But it isn't... My alignment has been checked 3 times in the past 6 months.... This time I'm going to get the spec sheet and check out the numbers myself.... Keeping the car is not an option at this point if I can't get some resolve on this issue. Additionally i'm still wanting to know what the build dates are for affected cars...

[n2oiroc]

I will find a local (Louisville KY) alignment place to align my car. What do I tell the alignment shop? "Car wanders at interstate speed and I want a 4 wheel alignment?" I also want a print out of the alignment specs for before and after alignment and also required alignment ranges - toe, camber and caster. What about measurements for cross camber or measurements that are not adjustable on our car? I want to be as specific as possible with the alignment shop.

 

I have a 2015 Legacy Limited with the wandering at highway speed problem. My car now has 21000 miles and although not as bad when new the problem still exists (after 3 dealer alignments). I am very glad to read in this forum some experts in car alignment are investigating.

 

Concerning the previous writers comments on "trammeling." According to Tire Rack my 18" Goodyear tires are slightly more than 1/2 wider (each tire) than the 17" stock tires, but according my dealer both width tires (17 inch and 18 inch) have the same alignment specs. A cause for trammeling? Has anyone with a 18 inch Legacy wheels with wandering issues switched wheels to a 17" Legacy wheel? Does it make any difference?

 

Thanks

 

Tell the shop you want .020" toe in on all 4 wheels, and the front camber set to max negative but matching. So if the right front goes to -.9 and the left front goes to -.7 set them both to -.7. Caster and rear camber are non adjustable. Cross camber is just the difference between sides and is non adjustable in the rear. You can go more toe in on the front and rear, but mine drives quite good at that # and the more toe in, the harder the tire wear.

[n2oiroc]

---I wish it was something as something as simple as you mentioned in your post.. But it isn't... My alignment has been checked 3 times in the past 6 months.... This time I'm going to get the spec sheet and check out the numbers myself.... Keeping the car is not an option at this point if I can't get some resolve on this issue. Additionally i'm still wanting to know what the build dates are for affected cars...

 

Unless there are red boxes on the sheet, most shops will call it good. You need to specify the exact #'s you want and make them hit them. The alignment can be "in spec" and the car will still drive terrible.

[08SpecB_DE]

The little dash at the center of the green is THE spec. Anything beyond that still in green is "within spec". It can be extremely hard to get all the specs dead on but I like to stay within .02 degrees for toe and .2-.3 degrees for camber.

 

Telling them the history you have with the car is not necessary unless they ask. Simply ask to get your alignment checked and see what happens.

[Beamercub]

I thought the same thing until i got an alignment. It seriously changed the car a ton.

 

Thanks for the post.. But what is the build date of your car?

[n2oiroc]

Thanks for the post.. But what is the build date of your car?

 

May 2015.

[XT-sub]

I posted most of this previously but for anyone who needs it these are the wheel alignment specs for our model Legacy/Liberty with inspection & adjustment values added. Where degrees & minutes were listed in the SM I have also added in dark red italic text, degrees to one or two decimal places, plus the calculated spec range.

 

Legacy wheel alignment specs from the 2015 SM: (also confirmed for Australian 2016 Liberty)

Figures for tyre size: P225/55R17 and P225/50R18

 

Front:

Toe-in: 0mm +/- 3mm (0.00" +/- 0.12") Toe angle (sum of both wheels): 0º00' +/- 0º15'. 0º +/- 0.25º

... Inspection value: 0mm +/- 3mm (0.00" +/- 0.12"). Range = +3mm to -3mm. (+0.25º to -0.25º).

... Adjustment value: 0mm +/- 2mm (0.00” +/- 0.08”). 0º +/- 0.16º. Range = +2mm to -2mm (+0.16º to -0.16º).

Camber: -0º15' -0.25º (tolerance: +/- 0º45' +/- 0.75º Differences between RH & LH: 45' 0.75º or less)

... Inspection value: –0°15′ +/- 0°45′. -0.25º +/- 0.75º. Range = +0.5º to -1.0º.

... Adjustment value: –0°15′ +/- 0°30′. -0.25º +/- 0.5º. Range = +0.25º to -0.75º.

Caster: 5º50' 5.83º (referential value)

Steering angle: Inner wheel: 37.6º Outer wheel: 32.8º (tolerance: +/- 1.5º)

Kingpin angle: 13º55' 13.92º (referential value)

Track: 1580mm

 

Rear:

Toe-in: 3mm +/- 3mm (0.12" +/- 0.12") Toe angle (sum of both wheels): 0º15' +/- 0º15'. 0.25º +/- 0.25º

... Inspection value: 3mm +/- 3mm (0.12" +/- 0.12"). Range = 0mm to +6mm (0º to +0.5º).

... Adjustment value: 3mm +/- 2mm (0.12” +/- 0.08”). 0.25º +/- 0.16º. Range = +1mm to +5mm (+0.09º to +0.41º).

Camber: -1º25' -1.42º (tolerance: +/- 0º45' +/- 0.75º Differences between RH & LH: 45' 0.75º or less). Range = -0.67º to -2.17º.

Thrust angle: 0º (tolerance: +/- 0º30' +/- 0.5º) Mean value of L & R wheel toe angles in relation to vehicle body centre line.

... Inspection value: 0º +/- 0º30’ 0º +/- 0.5º. Less than 30′ 0.5º when F/R centreline difference is 23mm (0.9”) or less.

... Adjustment value: 0° +/- 20′ 0º +/- 0.33º. Less than 20′ 0.33º when F/R centreline difference is 15mm (0.6”) or less.

Track: 1595mm

Wheelbase: 2750mm

 

The SM states: When the suspension-related components have been removed or replaced, perform “VDC sensor mid point setting mode” of the VDC.

[n2oiroc]

update: after my friend aligned it the wandering was dramatically reduced. it still pulled to the right a little though. a guy i work with has a brother with a shop and a new hunter alignment rack. we went over and double checked the #'s and it appears my rear toe was off. my friends rack read it as good.

 

today i went to the dealer for them to check out the rear camber and they realigned everything. i wasnt happy seeing the rear camber still off so i talked to the tech. he said that if the boxes are green, soa will not pay for any further work. i mentioned the .75* cross camber spec and he said the boxes are green so they wont do anything further. he said he could loosen the rear subframe and shift it to the drivers side a bit and that would even it out a little. i still need to get it on the highway and up to 80+ and see how it handles. if there is still an issue, ill have them shift the subframe and try again.

 

first pic is the check on a different rack after my friend aligned it. second pic is the dealer before and after. one thing to take away from this is alignment racks arent terribly accurate or consistent.

 

http://i153.photobucket.com/albums/s201/n2oiroc/C1FCB2AC-EC30-4D2B-A406-9B94FDDD4B91_zpsdxpxinbt.jpg

 

http://i153.photobucket.com/albums/s201/n2oiroc/2B8843FA-D59D-47AD-B0AF-231A7BECF6E0_zpsdm2zfbdk.jpg

[MrCobbs]

Installed the sway bar and new end links yesterday and it's solid on turns and straight on highway (60-80mph). The bounce on turns is reduced drastically as well. Decided to go with the 22mm for the WRX and not problem.

 

I will now do some research into the front sway and endlinks since I haven't really seen any clear and easy installs like in the rear.

[tigger73]

Installed the sway bar and new end links yesterday and it's solid on turns and straight on highway (60-80mph). The bounce on turns is reduced drastically as well. Decided to go with the 22mm for the WRX and not problem.

 

I will now do some research into the front sway and endlinks since I haven't really seen any clear and easy installs like in the rear.

 

Rear sway bar is a relatively easy job - bolt off and bolt on in your driveway.

 

Front sway bar is a different story. Generally it needs to be done in a workshop on a hoist and requires a non-trivial amount of disassembly (i.e. drop the sub-frame) to get the bar in/out. It's not a DIY job.

[MrCobbs]

Rear sway bar is a relatively easy job - bolt off and bolt on in your driveway.

 

Front sway bar is a different story. Generally it needs to be done in a workshop on a hoist and requires a non-trivial amount of disassembly (i.e. drop the sub-frame) to get the bar in/out. It's not a DIY job.

 

Have you done this install? If not I won't give this a try and will just take a the car to a shop nearby to get properly done.

 

Do you know which one will fit exactly? Such as the WRX or BRZ?

[tigger73]

Have you done this install? If not I won't give this a try and will just take a the car to a shop nearby to get properly done.

 

Do you know which one will fit exactly? Such as the WRX or BRZ?

 

I did this on my previous car and it was a BIG job. Though a decent workshop should be able to complete it in a couple of hours.

 

Not sure on correct front swaybar for the gen6 Legacy. If I was going to do it I'd be looking at the Tribecca as I think they are beefier than most going around. Though can't confirm fitment for gen6 - they do fit previous gens though.

 

There's a decent thread/discussion on Tribecca front sway bar here: http://legacygt.com/forums/showthread.php/2-5i-subaru-25mm-front-sway-bar-111718.html

[andrew_l_s]

IIRC the front sway bar simply rotates and slides out. Just have to pull a wheel for access.

 

I almost pulled the trigger on a 25mm bar from member CwhillVT until I realized my exhaust drone needs fixed ASAP. Had him compare to these measurements:

http://legacygt.com/forums/attachment.php?attachmentid=235723&d=1471306460

http://legacygt.com/forums/attachment.php?attachmentid=235724&d=1471306460

 

"I took the measurements and here is what I found:

Yellow 111.4cm - was a match

Red 94.7cm - is pretty close depending on where you take the measurement. The way the eibach bar bends are done is slightly different.

White 82.5cm - was a match

Teal 11.5cm - was a match

The bumps across the strait portion do not really match up. The eibach pockets are longer."

 

Based on this, a WRX front bar will fit. If someone wants to find out for cheap, pick up a stock WRX 24mm. They only run like 50 bucks on ebay. http://www.ebay.com/itm/222271270931?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

If I wasn't short on cash right now I'd be the guinea pig and find out.

[XT-sub]

i wasnt happy seeing the rear camber still off so i talked to the tech. he said that if the boxes are green, soa will not pay for any further work. i mentioned the .75* cross camber spec and he said the boxes are green so they wont do anything further.

Did you ask him where the green box was for the rear cross camber? That printout doesn’t show a box for rear cross camber, it can only be calculated from left & right. The rear cross camber of 1.1º is clearly outside the spec “Differences between RH & LH: 45' (0.75º) or less” set in the SM. So if there was a box it would be in the red - or am I missing something?

 

In the SM under RS-3 Rear Suspension for non-adjustable items it mentions; if other items exceed the tolerance range of the specification chart, check the suspension parts and connections for deformation. If defective, replace with new parts.

 

The rear toe being out could have been the reason why you still had a bit of wandering after your first alignment. I assume with all the alignments you had a full tank of fuel & no extra gear in the car.

 

I’ve struck differences between wheel aligners or results from different aligner operators before, but not as much as on yours. This is why I check as much as I possibly can & adjust what I can if needed. It isn’t difficult if you have a good level garage floor but it can be very time consuming. There are some good aligners around but some don’t spend the time to do it properly.

 

I wonder how much slack is in the rear sub-frame mountings before tightening. It doesn’t say much in the SM except; Always tighten the bushing in the state where the vehicle is at curb weight and the wheels are in full contact with the ground.

[XT-sub]

Installed the sway bar and new end links yesterday and it's solid on turns and straight on highway (60-80mph).

...

Decided to go with the 22mm ...

So how bad was your vehicle wandering on the open road prior to fitting the rear 22mm bar? I assume it was wandering.

[MrCobbs]

So how bad was your vehicle wandering on the open road prior to fitting the rear 22mm bar? I assume it was wandering.

 

 

 

Here in NJ, on the parkway, the lanes and 5 wide and pretty narrow and vary in elevation a lot. Before I used to constantly correct on the daily drive and bounce when exiting, even when the car was brand new. I read up on this forum and asked a nearby tuning shop and they agreed after checking my alignment, etc. that a sway bar would help. That proved right and it's a lot sportier now and I'm more confident.

 

I know the issue was gone when my wife noticed it when she drove the car and said, "That's so cool. How come it doesn't wobble anymore?". I explained to her what a sway bar is and how it would help with that and she replied, "You're such a nerd and I appreciate it".

 

 

Sent from my iPhone using Tapatalk

[Beamercub]

I dropped my car off monday, and it's thursday. I called yesterday wednesday and while waiting for the shop manager my call got disconnected... I would have thought he would have called back, nope... I'm beyond annoyed going to call them now.. Argh..

[XT-sub]

Before I used to constantly correct on the daily drive ...

 

Interesting, perhaps the stiffer 22mm (257% vs 99% over the stock 16mm) takes enough of the independence out of the rear suspension to make an improvement. But we shouldn't have to do this if the car is set up right.

 

I don’t want to turn this thread into another sway bar topic, but why I asked the question was because on our Liberty there wasn’t any improvement with wandering at all on a smooth highway at 110kph between the stock 16mm & the STi 19mm rear bars, & I’ve swapped them back & forth a couple of times when testing. The only difference has been less squirminess on the rear end when exiting a bridge approach, marginally better in a corner with throttle off, & a harsher ride when one rear wheel hits a bump independent of the other.

 

Looking at videos I took with an action cam of the rear sway bars & rear suspension doesn’t show any obvious difference between the two bars when driving at the same speed over the same paved streets with good surfaces near where I live, which includes a couple of corners & roundabouts. Even on what feels like a smooth street surface, the video shows the rear lateral links working up & down through their normal arc due to what is obviously not as smooth a surface as it feels – so I would guess the rear camber & toe are changing all the time.

[XT-sub]

Has anyone tried the recommended rear toe in an endeavour to try & fix the open road wandering?

 

The recommended (mid-point) total rear toe is 3mm (0.12 inch) which equals 0º15' or 0.25º.

 

It sounds like a lot of positive toe for the mid point but there must be a reason why Subaru specifies this setting.

[n2oiroc]

Did you ask him where the green box was for the rear cross camber? That printout doesn’t show a box for rear cross camber, it can only be calculated from left & right. The rear cross camber of 1.1º is clearly outside the spec “Differences between RH & LH: 45' (0.75º) or less” set in the SM. So if there was a box it would be in the red - or am I missing something?

 

In the SM under RS-3 Rear Suspension for non-adjustable items it mentions; if other items exceed the tolerance range of the specification chart, check the suspension parts and connections for deformation. If defective, replace with new parts.

 

The rear toe being out could have been the reason why you still had a bit of wandering after your first alignment. I assume with all the alignments you had a full tank of fuel & no extra gear in the car.

 

I’ve struck differences between wheel aligners or results from different aligner operators before, but not as much as on yours. This is why I check as much as I possibly can & adjust what I can if needed. It isn’t difficult if you have a good level garage floor but it can be very time consuming. There are some good aligners around but some don’t spend the time to do it properly.

 

I wonder how much slack is in the rear sub-frame mountings before tightening. It doesn’t say much in the SM except; Always tighten the bushing in the state where the vehicle is at curb weight and the wheels are in full contact with the ground.

 

Ill push things further on my next trip. The tech thinks there may be up to 1/4" of room to move the subframe. Any chance you can post a pic of the page from the service manual so i can show them? As of now the car doesnt seem to pull, but i havent went past 55 mph. Im working the next 3 nights so ill have plenty of 80+mph time to see how the wandering is compared to the less toe of the last alignment.

 

More good news is the guy i work with that has access to a rack, offered to make any adjustments i want. No reason i cant find the "perfect" alignment to share with everyone that has this issue.

[n2oiroc]

This new alignment sucks. Its like driving on train tracks, it darts. Not sure if its from too much toe in on the rear or the slight toe out in the front. I left a message for the service manager, them not fixing the cross camber is unacceptable. Its out of factory spec, it needs to be fixed.

[XT-sub]

Any chance you can post a pic of the page from the service manual so i can show them?

I should have that a bit later today.

This new alignment sucks. Its like driving on train tracks' date=' it darts. Not sure if its from too much toe in on the rear or the slight toe out in the front.[/quote']

Front toe-out should make it turn in better but less stable. I found when I tried front toe out on mine it wasn’t too bad (better than the toe in it originally had) but I don’t think it would have done the tyre wear any good so I went to 0º front toe. Not sure about the rear toe in – mine is 1.44mm (0.0576”) which is 7.2’ (0.12º). Inches & mm I calculated from the degrees I measured.

[XT-sub]

n2oiroc, the following links should be helpful:

 

Rear sub frame (RS-14). Note the 2nd dot point at the top.

Rear sub frame (RS-15)

Rear suspension (RS-4). (For anyone who uses the torque figure for T2, IMO that figure is too high).

Rear suspension (RS-5)

Rear suspension (RS-3). Note the 3rd dot point.

 

Edit: Added the below pages & post link.

Front suspension specs (FS-2)

Rear suspension specs (RS-2)

For adjustment figures see my earlier post here.

 

I’ve re-scaled the drawings smaller, but you can zoom in & right click ‘save image as’. That site is sometimes very slow to load from here.