HELP, rear end feels loose and wobbles at higher speeds after putting two new tires . - Ford Mustang Forum
Reply
 
LinkBack Thread Tools
post #1 of 16 (permalink) Old 03-10-2016 Thread Starter
Rookie
 
Luis Ceballos's Avatar
 
Joined: Oct 2015
Posts: 7
 
HELP, rear end feels loose and wobbles at higher speeds after putting two new tires .

Hey guys I need some advice here, couple days ago I installed two brand new nitto nt555 g2 on the rear of my 13 5.0 , they are 275/40/19 mounted on 19x9.5 sve drift wheels, my car is lowered on HR ss springs and has aftermarket control arms with poly bushings, also rear relocation brackets and the alignment is in spec. Well I installed the tires and set the pressure first at 36psi and went out for a test, initial impressions is that they hooked pretty good rolling from a 35-40 roll. Now it gets weird when I get up to highway speeds, when going straight at around 60+ mph if I start jerking the steering wheel left and right slightly the rear end feels really loose almost like if its hydroplaning. Feels like if the panhar bar was not in the car and the rearend was moving side to side while driving. What could be causing this on the tires? It has to be the tires, this happens now after they were put in. Does the pressure need to be higher to stiffen up the sidewalls? Do they need a brake in period or maybe doing a good burnout and heating them up can change how the act. ?

Luis Ceballos is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 03-10-2016
PONY Member
 
FuelforFire87's Avatar
 
Joined: Apr 2011
Location: Lombard
Posts: 412
 
Were the tires balanced correctly? I would take it back to the shop that installed the tires and have them check that they are balanced. Improperly balanced tires will cause vibrations at high speeds, and is probably what is causing your issues.

Sent from my SAMSUNG-SM-G890A using Tapatalk


2014 Mustang GT 6R80, Procharger Stage 2 D1SC, BBK 85mm TB, Boss IM, Sai Li fuel system. Circle D 3C, 1-7/8" Kooks Long Tubes w/Offroad X Pipe, Lethal Over-Axle Pipes, Corsa Quad Axle-Back, Eibach Pro System Plus, BMR K member, Shaftmasters DS, Forgestar CF-5 Wheels and Nitto NT05 tires. Lund Tuned

Lots of suspension goodies and some other stuff I can't remember.
FuelforFire87 is offline  
post #3 of 16 (permalink) Old 03-10-2016
GT Member
S197 Member
 
csamsh's Avatar
 
Joined: Mar 2012
Location: OKC
Posts: 2,259
       
Is it the first time you've had the aftermarket wheels on the car? Take them off and make sure you took off the clips that are on two of the rear wheel studs from the factory.

What tires are on the front? Could be that the 555's are harder and lose grip while the fronts hold on

2002 C5 Z51. MCS 2WNR TT2 coilovers, 18x11 Forgestars, 315's, yada yada. Built Z06 T56. Bolt ons. Coming soon to a CAM event near you.

2013 F150 6.2L. 9mpg.

csamsh is offline  
 
post #4 of 16 (permalink) Old 03-10-2016
Apprentice
 
Kestral's Avatar
 
Joined: May 2015
Location: Hinsdale
Posts: 108
 
May sound dumb but check your lug nut torque make sure they are tight! It is easy to overlook. The odds of it being the tires is slim it's definitely possible but slim. Have the wheel balance checked on the wheels in question.
Kestral is offline  
post #5 of 16 (permalink) Old 03-10-2016 Thread Starter
Rookie
 
Luis Ceballos's Avatar
 
Joined: Oct 2015
Posts: 7
 
I work at a dealer as a tech so I mounted my own tires and balanced them, I torqued all the lugnuts to 95lbs, my problem is not vibration, my car is very smooth at highway speeds as far as tire vibrations. And I have had my wheels for 1.5 years now and this is the 3 set of tires I have on the rear, all previous tires including Pirellis Corsas that were similar to these nittos as far as grip did not have this problem. The last set was a pair of Michelin Pilot Sports, they did not grip for crap but they handled directional input better than these nittos. Im going to try and bump up the tire pressure 42 psi tomorrow to stiffen the tire up and see if that fixes the issue. Today while driving I aimed my mirror down to take a look at my sidewall and while moving the steering wheel left and right I could see the sidewall flex and that is with 32 psi. Nitto told me from their calculation that the equivalent air pressure or this tire on my car was 25.5 psi when converted from the stock pressure and stock wheel and tire size, but 25 psi is way to low to be driving everyday , it probably works at the drag strip but not the street. Anyways lets see if increasing the tire pressure will stiffen the sidewalls to not flex so much and cause the rear to wobble so much. And I have already looked everywhere and visited other forums of people having the same issue when putting new tires in their car and its always a high performance tire with soft compound. Other people are saying to break them in but comeone does a tire really needs to be broken in, a nice hot burnout should do it.
Luis Ceballos is offline  
post #6 of 16 (permalink) Old 03-11-2016
GLOBAL MODERATOR
S197 Member
 
5.0 Coyote's Avatar
 
Joined: Oct 2010
Location: San Carlos Park
Posts: 2,339
               
You might have a defective tire,I have seen brand new tires where the tread is loose from the carcus of the tire, and it squirms around,take it back and have the tires checked.
5.0 Coyote is offline  
post #7 of 16 (permalink) Old 03-11-2016
GT Member
 
5LHO's Avatar
 
Joined: Dec 2011
Location: Point Roberts
Posts: 1,741
 
Are you mixing brands compared to what's up front, since you say you bought two new? The two sets might not be liking working together.

2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85

2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP
5LHO is offline  
post #8 of 16 (permalink) Old 03-11-2016
GT Member
 
dusman59's Avatar
 
Joined: Oct 2010
Location: Mesa
Posts: 1,191
 
I'm really interested in whats causing this problem. I have been considering the 555 g2's. 275 40 19 on Brembo 9 inch wide wheel might exhibit the same problem. Maybe the sidwalls are not stiff enough.


2011 Red Candy /build 2/1/11/ 401A
MT with Redline MTL/ Brembos/355's/glass roof
Shaker 1000/Scoops/Clear bra/Steeda UCA and PH bar
Redline hood lifts/Bilsteins with Ford Racing P springs & axle bks
UPR catch can/whiteline kdt928/MGW shifter with Epco ball
Shaftmasters DS/BMR loop & relocation brackets
Nitto 555 G2's/Steeda jack rails
dusman59 is offline  
post #9 of 16 (permalink) Old 03-11-2016
Rookie
 
TMSBOSS's Avatar
 
Joined: Aug 2011
Location: Steward
Posts: 50
 
What tires do you have on the front?

A mismatch front to rear with tires that are either stiffer or softer can cause issues like you describe

2012 KB Boss: MGW Shifter & Knob, FRPP LCAs, Relocation Brackets, Adj Panhard Bar,P Springs, Enkei & Nittos, MM Plates, Girodics rotors, Pagid pads, DSS Driveshaft, Trans scoop, Brake cooling ducts.
2013 V-6: MT-82, MCA edition, Recaros, Performance package, American Racing classics W/Pilot Sports.
TMSBOSS is offline  
GT Member
 
PMDmustang13's Avatar
 
Joined: Jun 2012
Location: Omaha
Posts: 1,651
 
Maybe I am wrong. But I don't think adding air in the tire will stiffen your sidewall. And I don't know if going over the recommended tire pressure indicated in the owners manual is good either.

And I believe the proper torque on the lug nuts is supposed to be 100 ft-lbs dry threads. No lubricant.

2013 GT, Track Pack, Recaros, Kooks Axlebacks, Airaid CAI, BMR Rear Adj. LCAs, BMR Relocation Brackets, JLT Oil Separator(s), Barton 2 Post Shifter Bracket, Steeda Motor Mounts, Barton Shifter, JHR Clutch line, BMR adj. UCA and Mount, Kooks 1 3/4 headers/catted H, DSS Al Shaft, BMR Loop, Vogtland Sport Springs front/BMR rear, Strange Adj. Struts/Shocks, Extended ball joints, Steeda Bumpsteer Kit, Whiteline Tranny Mount Bushing, Borla Overaxles, BMR Watts, Vorshlag 3" Ducts
PMDmustang13 is offline  
SHELBY GT 350 Member
 
2oo5GT's Avatar
 
Joined: Nov 2007
Location: Valdosta
Posts: 5,089
 
Bump it down to 30psi. Had the same thing happen years ago and it was too much pressure. Too much will ballon the center and make it loose feeling.
2oo5GT is offline  
GT Member
4.6L Member
S197 Member
 
Norm Peterson's Avatar
 
Joined: Dec 2012
Location: Delaware Twp
Posts: 1,685
 
Garage
Brand new tires are likely to still have some of the mold release agent in/on the tread rubber. Don't expect them to perform as intended until you've scrubbed it off. This should occur within a couple hundred miles of normal driving, and that's arguably the better way to get this done. Get this done and see if the problem goes away.


There isn't enough information for me to suggest a different rear tire pressure.


Norm

'08 GT coupe, 5M, wheels, tires, pads, fluid, a few suspension mods . . . still almost stock height
'19 WRX, 6M (the "family sedan")
'01 Maxima 20AE, 5M (the spare and occasional winter driver)
Norm Peterson is offline  
Rookie
 
TheJMan48's Avatar
 
Joined: Apr 2014
Location: Anthem, AZ
Posts: 41
 
Quote:
Originally Posted by Norm Peterson View Post
Brand new tires are likely to still have some of the mold release agent in/on the tread rubber. Don't expect them to perform as intended until you've scrubbed it off. This should occur within a couple hundred miles of normal driving, and that's arguably the better way to get this done. Get this done and see if the problem goes away.


There isn't enough information for me to suggest a different rear tire pressure.


Norm
This. I just put 4 new tires on my car and noticed the exact same sensation when driving it home. After a few days of driving to and from work (and some spirited cornering for good measure), the car drives just like it did before replacing the tires. Give it a few days and see if it's still a problem.
TheJMan48 is offline  
BOSS Member
 
Thereaper's Avatar
 
Joined: Jul 2007
Location: Mobile
Posts: 4,571
 
Garage
Bump for update. Did the problem go away?

Shadow Black 2018 GT 10R80-355
Thereaper is offline  
post #15 of 16 (permalink) Old 03-18-2016 Thread Starter
Rookie
 
Luis Ceballos's Avatar
 
Joined: Oct 2015
Posts: 7
 
Ok guys sorry I have been away for some days, well I lowered the tire pressure to 30 psi and the car feels way better, like the nitto rep said lowering the pressure helped. Its funny because my front tires are some use takeoffs from a Mercedes benz s class and they are Michelin runflats 275/40/19 just like the rears, im pretty sure these tires are playing a role on how the rears behave because of how hard those tires are and runflats I guess act different. Well as far as for the person that was wondering on the nt555 g2, get them, I love the tires, they got decent thread wear at 320 and they hook really good, not like drag radials but man once heated up they stick to the ground. I think having it at 36 psi was too high and caused the tire to ballon a bit and that's why I was getting that looseness sensation on the rear.

Luis Ceballos is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1