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Jacksonville, Fl
 
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Could a recent tire rotation cause front end looseness?

Quick question:

I recently put new rear tires on the 911 (245/45/16s) and rotated the fronts (225/50/16s). The car was aligned, but I am noticing that the car feels a bit looser in the front. Noticeably at high speed. But still corners like a champ

I'm hoping this is just from the uneven wear of the fronts and it will settle with time. Anything else I should look at?

They are uni-directional, and on correctly
The pressure is 36R/ 30F
No change in brand or size.

Thanks!
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Alex
Jacksonville, Fl
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Old 04-15-2018, 11:33 AM
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...
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Old 04-16-2018, 01:26 AM
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Tire Rotation

Alex, forgive me if if i am wrong , you mean you
changed both front tires from left to right, so does that mean
one tire is not rotating in the correct direction, or
am i incorrect here. regards.
Old 04-16-2018, 04:50 AM
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or maybe he put the 225 up front that were at rear before?

a "loose" front is lacking downforce and weight... did you change anything? did your fuell tank get empty?
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Old 04-16-2018, 05:10 AM
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Did you get a print out of the alignment, before & after?
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Old 04-16-2018, 05:39 AM
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Jacksonville, Fl
 
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Sorry for the confusion. In addition to putting on new rears tires, I had the front tires rotated. Switched LF and RF tires. No weight or aero changes. I wouldn't say its extremely loose, but just a little more floaty at high speeds

My thoughts about the tire rotation were: If a uni-directional tire that wears more on the outside of the tread, gets switched to the other side (where the worn side is now on the inside), would that make for less "planted" steering? I'm thinking the current toe of the car is causing less tread on the road.

Potential "bro-science" here...
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Old 04-16-2018, 05:40 AM
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i would check toe with tape measure just to make sure they didnt royally screw it up. But changing tires usually does change the feel of the steering iv found especialy on the 911
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Old 04-16-2018, 06:03 AM
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My thoughts, worth what you're paying.

You state the front tires are unidirectional. Did you have them removed from the rims and remounted so they continue to rotate in the correct direction, or were they just swapped side-for-side?

If they were remounted, then any irregular wear from camber/toe settings will now be on the opposite side of the tread and the amount of tread making firm contact will be diminished. Imagine a FR tire worn a bit more on the outside due to toe settings and steering. Move that tire to the FL, mount it so it rotates in the same direction, and the worn side is now on the inside.

This can certainly lead to a different, more squirrely, feel, IMO.
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Old 04-16-2018, 06:53 AM
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Did you get the exact same model of tires installed on the rear as the front?
Old 04-16-2018, 06:56 AM
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I would Jack each front side up, one at a time, and manually shake the tire at 12 and 6, then at 3 and 9. You might get suprised. This will check your steering rack, ball joints, bearings, tie rods. You can also place a rod, stick crowbar under the raised tire and lift the tire by hand against the suspension. I was in the process of changing to turbo tie rods on my 86 Carrara, and found that the bearings on both sides were loose, one worse than the other, and they had been worked on by PO. And the shocks needed replacing. Also found the brake flex lines to be too stiff. I changed everything out. The car is stored in the winter and has 86,000 mi.
Old 04-16-2018, 07:22 AM
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Quote:
Originally Posted by ossiblue View Post
My thoughts, worth what you're paying.

You state the front tires are unidirectional. Did you have them removed from the rims and remounted so they continue to rotate in the correct direction, or were they just swapped side-for-side?

If they were remounted, then any irregular wear from camber/toe settings will now be on the opposite side of the tread and the amount of tread making firm contact will be diminished. Imagine a FR tire worn a bit more on the outside due to toe settings and steering. Move that tire to the FL, mount it so it rotates in the same direction, and the worn side is now on the inside.

This can certainly lead to a different, more squirrely, feel, IMO.
Yes the tires were ripped from each front wheel an swapped. Your summation in the second paragraph is what I was wondering. Hoping it will settle over time
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Old 04-16-2018, 07:31 AM
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Quote:
Originally Posted by old man neri View Post
Did you get the exact same model of tires installed on the rear as the front?
Same model, different sizes. Proxies T1R.
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Old 04-16-2018, 07:32 AM
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Quote:
Originally Posted by Oneredspyder View Post
I would Jack each front side up, one at a time, and manually shake the tire at 12 and 6, then at 3 and 9. You might get suprised. This will check your steering rack, ball joints, bearings, tie rods. You can also place a rod, stick crowbar under the raised tire and lift the tire by hand against the suspension. I was in the process of changing to turbo tie rods on my 86 Carrara, and found that the bearings on both sides were loose, one worse than the other, and they had been worked on by PO. And the shocks needed replacing. Also found the brake flex lines to be too stiff. I changed everything out. The car is stored in the winter and has 86,000 mi.
I will try that... And hope your wrong...
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Old 04-16-2018, 07:33 AM
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correct rotation with directional tires

This is the correct way with directional tires.
Change them back to the way you had them on the front,
until you need to fit new ones regards.
Old 04-16-2018, 07:00 PM
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Check your air pressure, they were prob a bit low previously, the combo of the wear and extra pressure will make the rpfrint end feel light. Mine is sensitive to a pound or two...
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Old 04-16-2018, 07:14 PM
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Quote:
Originally Posted by wayne robson View Post
This is the correct way with directional tires.
Change them back to the way you had them on the front,
until you need to fit new ones regards.
Not with different width tires front and back. That would be exceptionally squirrely.
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Old 04-17-2018, 05:31 AM
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Quote:
Originally Posted by RDM View Post
Not with different width tires front and back. That would be exceptionally squirrely.
LOL. Yeah running 7 and 8s doesn't really make that an option
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Old 04-17-2018, 06:14 AM
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Check all four pressures. Under inflated rears could cause floaty fronts. Over inflated fronts could cause floaty fronts too.

I've spaced out and done some dumb stuff to my cars late in the day.

I'm guessing it has more to do with your new rears than it does your old, rotated fronts. Probably just have to fool with the pressures to get the right feel all around.

(and just to ask a dumb question: are you sure they put the rears on the rears and the fronts the fronts?)
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Old 04-17-2018, 06:28 AM
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Check the Toe, if its zero or out, it takes some getting used to.
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Old 04-17-2018, 07:37 AM
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Jeez, take the easy route:

Swap them back (un rotate them) and see if the floaty feeling goes away. If so you have your answer. 10 minute exercise, depending on how far away from a freeway speed road you live.
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Old 04-17-2018, 08:09 AM
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