Swaying with new rear tires.

[NitroYellowMKV]

The electric power steering rack on my 2021 went out when my car had 1,500 miles and the dealer had to replace the whole assembly.

It’s bone stock and has never been tracked. All I was doing the day it failed was picking up steaks for the grill and I doubt that put any stress on it!

I guess my point is the Supra sometimes has issues with the electric power steering rack failing (similar to the Z4). It seems kind of random.

good to know it is an issue that happens, what symptoms did you experience? mine the car has very unpredictable steering, loose, lots of play, any quick maneuver and the wheel goes left and right and makes the car dangerously uncontrollable and then traction control goes crazy trying to correct itself but can't. Under straight line acceleration its constantly fighting you to go straight.

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[SpeedRacer]

good to know it is an issue that happens, what symptoms did you experience? mine the car has very unpredictable steering, loose, lots of play, any quick maneuver and the wheel goes left and right and makes the car dangerously uncontrollable and then traction control goes crazy trying to correct itself but can't. Under straight line acceleration its constantly fighting you to go straight.

My car threw a ton of stability & safety control related codes for several days before the electric power steering (EPS) went out completely.

It never fought me but threw around a dozen codes ranging from issues with stabilization, chassis, rear differential, pedestrian detection, combined with notices of decreased performance and increased steering effort.

The Supra tech reset the computer but couldn’t get the EPS to communicate with the car so he replaced the whole steering rack and it’s been fine ever since then.

 

[Cyph]

I got new stock PSS rears put on last week and they were swaying real bad going highway speeds. I couldn’t imagine driving with vsc off while swaying like it was.

Any hard acceleration and the car would sway the faster it went. My older rear sets of PSS didn’t do this.

Makes me think it’s just a coincidental batch of tires that have too much of that factory grease still on them.

 

[underdonk]

I got new stock PSS rears put on last week and they were swaying real bad going highway speeds. I couldn’t imagine driving with vsc off while swaying like it was.

Any hard acceleration and the car would sway the faster it went. My older rear sets of PSS didn’t do this.

Makes me think it’s just a coincidental batch of tires that have too much of that factory grease still on them.

Again, swaying is just a weird word. Under hard acceleration are you just on the cusp of the breaking the tires loose and it's shimmying at the edge of adhesion like a RWD car does?

 

[Count Mackula]

Again, swaying is just a weird word. Under hard acceleration are you just on the cusp of the breaking the tires loose and it's shimmying at the edge of adhesion like a RWD car does?

It feels “floaty.” You don’t feel anything different from a dead stop. But when you get to 70-80 MPH it feels like you tires aren’t touching pavement.
As I mentioned earlier, I was on the freeway and the ESC would kick on at the slightest turn. It was strange.

 

[Thraxbert]

A car that feels floaty at speed and is constantly triggering ESC has a faulty rear alignment, likely rear toe is wildly out of spec.

Doesn't matter if you've never touched the alignment. Jacking the car up can alter the alignment. It's the alignment.

 

[VA90]

Assuming alignment is fine and tire pressures are correct (and tires aren't tramlining), it's the LSD and traction control doing what it's supposed to do.

 

[underdonk]

Assuming alignment is fine and tire pressures are correct (and tires aren't tramlining), it's the LSD and traction control doing what it's supposed to do.

That's what I'm thinking too.

 

[razorlab]

Jacking the car up can alter the alignment. It's the alignment.

You have WAYYYYY bigger problems if this was actually true.

I need to correct you here so people don't think this is an actual thing. Jacking the car up properly will not make anything move out of alignment. Completely false.

 

[Count Mackula]

As mentioned earlier, I alleviated the problem with reducing my tire pressure.

You have WAYYYYY bigger problems if this was actually true.

I need to correct you here so people don't think this is an actual thing. Jacking the car up properly will not make anything move out of alignment. Completely false.

I was thinking the same thing. How does jacking your car up screw with the suspension? Makes no sense.

As I have mentioned previously, the problem was solved when I adjusted the tire pressure to a lower psi. The only thing I can think of that MAY have resulted in the “floaty” feeling in the rear is having brand new meaty tires inflated really high with older tires in the front.

The old rear tires were wearing quicker on the insides. So I presume the front tire must be doing the same. Perhaps that could be the root cause of it.

 

[Thraxbert]

You have WAYYYYY bigger problems if this was actually true.

I need to correct you here so people don't think this is an actual thing. Jacking the car up properly will not make anything move out of alignment. Completely false.

Not false at all.

I am not saying:

1. Jacking up your car is guaranteed to alter your alignment.
2. That you shouldn't jack up your car for fear of altering your alignment.
3. That this is a common occurrence.

I am saying:

1. Factory Toyota alignment can be pretty poor.
2. Factory Toyota alignment can and does have control arm bolts that are loose enough to be disturbed by common maintenance work. Toe arms are especially suspect on the Supra.
3. Horsing wheels on and off the hub can affect toe.
4. And most importantly of all: taller and wider-than-factory wheel and tire setups can and will change suspension geometry.

 

[razorlab]

Lol, but you did say it.

Also, taking off wheels can move toe settings?

Come on. People aren’t driving down glass roads with no bumps. We drive on roads with bumps, we turn through corners that put wayyy more load on the suspension than taking a wheel off.

Also, I would LOVE to hear you explain how a taller and/or wider wheel with the exact same center point changes actual suspension geo. Please tell us more… or tell people that use hub mounts for alignments, I’m sure they would also love to hear as well.

Not false at all.

I am not saying:

1. Jacking up your car is guaranteed to alter your alignment.
2. That you shouldn't jack up your car for fear of altering your alignment.
3. That this is a common occurrence.

I am saying:

1. Factory Toyota alignment can be pretty poor.
2. Factory Toyota alignment can and does have control arm bolts that are loose enough to be disturbed by common maintenance work. Toe arms are especially suspect on the Supra.
3. Horsing wheels on and off the hub can affect toe.
4. And most importantly of all: taller and wider-than-factory wheel and tire setups can and will change suspension geometry.

 

[underdonk]

 

[calmeda1]

I'm also having this issue after the same condition. Got brand new PSS's on the rears and now my car sways left and right when going in highspeeds. I adjusted the pressure and not much inprovement. I might just change my fronts and re-align

 

[FLtrackdays]

I'm also, having this issue after the same condition. Got brand new PSS's on the rears and now my car sways left and right when going in highspeeds. I adjusted the pressure and not much inprovement. I might just change my fronts and re-align

OEM wheels? A good alignment does wonders for this car. Especially if you’ve changed your wheel & tire size. I have SPL parts and eccentric lockouts so we can set it and attempt to forget it the beginning of track season. At the end of season, I’ll put my OEM wheels back on and go back to a spec alignment.

Do you have a race alignment shop in your area? They tend to have better equipment and know how to deal with nuances than your big box cookie cutter “throw it on the machine Charlie!” place

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