Rub after new wheels/tires

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
Hi All,

I have a rubbing issue when the body compresses going over large bumps/sharp change in elevation. Noise is transferring through the driveline and I can hear it through the console (that's what it sounds like). The rubbing will repeat in short bursts after the suspension has settled sometimes (really lost at this one). Couple of facts:

1. Has a T56 Magnum XL transmission with the 3" DSS driveshaft.
2. Changed from stock 18x8 wheels to 2010 GT500 18x9.5 wheels with a 45 offset.
3. Went from 235/50/18 to 275/40/18 at all four corners.
4. Has FRPP Adjustable handling pack (1 inch drop)

According to the tire calculator my ride height dropped another .3 inches. I've looked underneath and can't find anything rubbing. DS looks OK and the axle is centered using my adjustable panhard.

Any ideas?

Thanks.
 
Last edited:

redfirepearlgt

forum member
Joined
Mar 19, 2011
Posts
2,497
Reaction score
263
I run a 27.2" 305/30/20 on a 20x10.5 +45mm rim on the rear and have no rubbing in the back at all. I only run a 255 up front so I can't give you any help there. My car is on a 1.5" BMR drag spring front and rear. I would be more inclined to think your problem is up front. You may need a +40mm offset up front or a spacer to give some clearance from the struts. As I recall GABE runs a pretty wide setup both front and rear. Hopefully he will see this and give you some first hand advise. I think he runs 275's on the front of his cars.
 

stkjock

---- Madmin ----
Staff member
Administrator
Super Moderator
S197 Team Member
Joined
Jul 10, 2007
Posts
40,218
Reaction score
3,135
Location
Long Island NY
Can u replicate the noise when the car is still by pushing down on the front or rear end? that could start to isolate where it's happening.
 

oldVOR

forum member
Joined
Apr 9, 2015
Posts
1,746
Reaction score
483
Location
Northern Virginia
I've run 18x9.5 ET45 with 275/40 square and had no rubbing issues front or rear. There's tons of clearance on both ends with this setup. I doubt that any rubbing would happen with this setup.
I'm presently running 19x10 ET43 with 285/35 square and have no rubbing issues front or rear. There's ton's of clearance on both ends with this setup as well.

Have you checked the constant velocity joint on the drive shaft?
Did you adjust the pinion angle when the Mustang was lowered?
Is the rear suspension stock? How many miles on the components?
 

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
I've run 18x9.5 ET45 with 275/40 square and had no rubbing issues front or rear. There's tons of clearance on both ends with this setup. I doubt that any rubbing would happen with this setup.
I'm presently running 19x10 ET43 with 285/35 square and have no rubbing issues front or rear. There's ton's of clearance on both ends with this setup as well.

Have you checked the constant velocity joint on the drive shaft?
Did you adjust the pinion angle when the Mustang was lowered?
Is the rear suspension stock? How many miles on the components?

Thanks for the input. It's a one piece Aluminium Drive Shaft made for the T56, so no joints. Or do you mean where it meets the axle? How do you adjust the pinion angle and what should it be?

Rear suspension is Ford Racing setup, P springs, adjustable panhard, sway bar. Less than 10K miles on the package as a whole. Thanks for the help.
 

Pentalab

forum member
Joined
Mar 5, 2013
Posts
5,208
Reaction score
1,092
The DSS uses a constant velocity joint at differential end.... and a U joint at tranny end. On paper, by using the CV joint at differential end, the pinion angle should not be critical. If pinion angle requires to be adjusted, it's done via an adjustable UCA.

You won't have a rubbing issue with those 275's and GT-500 wheels, not gonna happen. A 275-40-18 is only 26.66" tall. Your oem 235-50-18 is 27.25" tall ( a .6" difference). .6 /2 = .3"
You just lowered the car another .3". Measure between exact center of wheel hub..and top of wheel well arch.... that method eliminates the wheel diameter completely from the equation, when calculating how much you really lowered the car..via lowering springs.

IF the new DSS is rubbing anywhere, you will see score marks on the shaft....= bad news. Any score marks will be readily apparent.
On a side note, DSS sez their CV joints are field replaceable..for $100.00

DSS also sez they are balanced to 9200 rpm.

Before you rip something up, check everything in there.... tire to front strut clearance, camber, toe, loose / trashed wheel bearings, adjustable pan hard bar, front + rear springs... spring perches etc, etc.

Are you sure it's only a 3.00" DS ? My DSS is 3.5"..on my 2010 auto...which still leaves plenty of clearance. Was your DSS installed correctly ? What year is your car ?

Try driving over a speed bump, slow like, and see if it's coming from front end.... or back end. Or drive over a speed bump, slow, at a gross angle, so the right front hits the speed bump 1st...followed by the left front.
 
Last edited:

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
^ Pentalab, this is the driveshaft I'm using, 3.5" you are right: http://www.driveshaftshop.com/ford-...shaft-for-oe-pinion-flange-spicer-forged-yoke. Driveshaft was installed correctly. My car is a 2010 GT.

My problem is why after only a .3" drop and wheels/tires that are known to be no issue, why is it rubbing? I'll jack the car up, take all the wheels off, reinspect the DS and see if anything pops out. I did not see any marks on the DS or the tunnel when I looked last time. I usually have to be going faster than parking lot speeds to hear it, but I can try that too. Thanks for your time.
 

Gabe

Whippled Coyote
Joined
Aug 7, 2011
Posts
8,437
Reaction score
1,520
Location
NC
I run 2010 GT500 convertible wheels (18x9.5 w/45mm offset) and I run 285/40/18 fronts and 305/40/18 rears.
No rubbing.

I highly doubt that whatever noise you're hearing is tire-related.

I've even briefly run the rear 305/40/18 set-up on the front.
I autocrossed the car like that. Still no rubbing.

I think I ran a small 4-5mm front spacer with the 305's, but regardless, your 275's aren't rubbing.

Also, the .3" shorter tire means the car only dropped .15" since that .3" is for the whole tire height and the car bolts up in the middle of the tire.
So that's a negligible difference.

To me it almost sounds like you might have a rear diff noise going on.
 

redfirepearlgt

forum member
Joined
Mar 19, 2011
Posts
2,497
Reaction score
263
^^^ Bodda Book, Bodda BOOM! You got it from one of the experts OP. This guy knows his tire and wheel fitment. And he's pretty savy with a lens as well.
 

Pentalab

forum member
Joined
Mar 5, 2013
Posts
5,208
Reaction score
1,092
His tire is .6" smaller diameter than oem. He's effectively lowered by just .3" . Moot point, it's not tire / wheel related. Something else in there has cut loose.
 

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
Well, I spent quite a while underneath the car today. I found absolutely nothing. Axle is not hitting, exhaust isn't either, driveshaft is fine, tires/wheels have plenty of clearance. I'm at a loss.

I will mention that I bought it used (2 owners before me) and noticed that there had been a smaller rear end collision on the passenger side that wasn't on the Carfax. Nothing major, but enough to break one of the plastic rear bumper brackets and mess up the gap. About ready to take it to a shop. Can anyone recommend a Mustang shop in the NJ/NY/PA area?
 

redfirepearlgt

forum member
Joined
Mar 19, 2011
Posts
2,497
Reaction score
263
When I'm troubleshooting a problem that arose right after a modification or repair at work, I first undo (when possible) what had been redone to see if the problem goes away. While the consensus is that there is not a rubbing issue due to tire/wheel fitment, the first thing in troubleshooting is to establish probable causes. The second then is to narrow the list down to the final cause through elimination. Hopefully you don't have to repeat steps one and two again. So the first thing I would do if I were you as simple as it would be, would be to put the front original wheels back on and go for a ride. If the problem is still there, put the back two original wheels on and go for another ride. If the problem still exists you have at least proved to yourself that the consensus here is correct and move on to other potential causes.

PS - while pulling the wheels take a moment to inspect for anything bent or damaged around the rotor or caliper. Check the the protective covers on the back side of the rotors. Make sure any aftermarket fake caliper covers are rubbing if there may be some installed. Inspect for rubbing on the inside of the tires and on nearby struts, springs, etc. I seriously doubt you are going to find a rub issue, but you might find something that was knocked loose or bent during the swap out.

BTW - You are telling the whole story correct? This isn't another one of those "Oh btw I forget to mention that in addition to wheel mod, I did a full suspension coil over mod as well, and exhaust, and LT's and ......fill in the blank. Nothing more frustrating when a person seeks help on a website and two pages into the process says, "Oh btw I also did this or that at the same time...or I wrecked the car just after I did the mod, or ...again.......fill in the blank. Be kind enough if you have not, to elaborate. Thanks.
 
Last edited:

Gabe

Whippled Coyote
Joined
Aug 7, 2011
Posts
8,437
Reaction score
1,520
Location
NC
Is the car running factory gears in the rear end?
My '13 GT and my wife's '08 GT500 both have rear gear noise, usually only heard at highway speeds, but it comes and goes as we let off the gas or go over undulating sections of road (where the load changes on the gears).
My car has factory 3.73's and my wife's has non-stock 3.73's. Both are noisy.

How many miles on the car?
Also, did you replace any rear control arms around the same time as doing the wheels/tires?


Pentalab, you're right about the height differences. I apparently ignored his stock size of 235/50/18 that normally calculates out to 27.25" tall.
But like you said, the .3" drop in vehicle height is not causing whatever noise he has.

Unless the extra drop is affecting the rear pinion angle just enough to make it noticeably noisy.
 

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
Guys, appreciate all the help and the suggestions. T56 Magnum, 2010 GT, 3.31 gears, Full Ford Racing Adjustable Suspension and the wheel/tire combo change.

I just remembered about this, but the car fell off the jack when putting the new wheels on. Jack fell to the passenger side and was wedged under that axle, so the car didn't really hit the floor. All other tires were on (Driver/Passenger front and Driver Rear). I inspected for damage and didn't see anything. No odd vibrations.

As a basic idea (and I know this is not very scientific) I measured from the ground to the wheel well lip (car sitting on the ground). Rear driver side was approx. 29" and rear passenger side was approx. 28". Front sides are equal at about 28". Is it possible the axle is bent on the passenger side? Wouldn't it be that the axle was bent upwards on the passenger side and have the higher height? Sorry for not mentioning this before.

Bought the car with 29K, has 44K now. Have had the suspension on since about 35K or so. Just did the wheels/tires this spring. Calipers/rotors OK, dust shields OK, no caliper covers. Stock exhaust except for axleback Corsas. Rear control arms have not been touched. No longer have the stock wheels/tires unfortunately - but I know there was no rubbing with them on.
 

oldVOR

forum member
Joined
Apr 9, 2015
Posts
1,746
Reaction score
483
Location
Northern Virginia
Have you checked the rubber bushings in the UCA and LCA's? If they are worn out or gone, the vibrations could easily be coming from them.

When you lowered the suspension, did you loosen the UCA and LCA mounting bolts to allow the arms to be clocked to their new positions? If not, it can cause the rubber bushings to wear at an accelerated rate.

It's not unusual to have differences in ride height from side to side. Most vehicles are not symmetrical and will have more weight from one side to the other, thus, causing the ride height to differ accordingly.

I highly doubt the axle housing would bend from your description of the jack slipping on the axle.
 

Norm Peterson

corner barstool sitter
Joined
Feb 5, 2011
Posts
3,615
Reaction score
316
Location
RIP - You will be missed
Unless the extra drop is affecting the rear pinion angle just enough to make it noticeably noisy.
"Drop" that's coming from shorter tires does not affect pinion angle at all. Pinion angle is strictly a function of drop between the axle and the body.

Check that . . . between axle and body, plus between body and engine/transmission. If the engine was lowered and/or if the transmission crossmember sits the new transmission higher or lower than the OE transmission was sitting, that could be causing a pinion angle shift.

Adjustable LCAs can also be used to correct pinion angle, but you do have to be careful to adjust both of them by the same amount (this is easier to do with off-car adjustables).


On edit - what is the condition of the bushings in your current LCAs? Are they the OE LCAs? Badly deteriorated ones whether OE or aftermarket could be allowing pinion angle shifting going from acceleration to deceleration and/or when the rear axle goes over bumps.


Norm
 
Last edited:

Norm Peterson

corner barstool sitter
Joined
Feb 5, 2011
Posts
3,615
Reaction score
316
Location
RIP - You will be missed
Separate thoughts occurring because I'm giving thought to a Magnum XL and some other driveline bits for my '08.

Doesn't the Magnum XL transmission require either a different transmission mount or crossmember?

Are the crossmember and tranny mount bolts all properly torqued?

If you aren't getting a vibration at highway and higher speeds, chances are that the pinion angle isn't all that far off.


Norm
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,903
....... Can anyone recommend a Mustang shop in the NJ/NY/PA area?

I'm near the PA/DE/MD border. I had my ASE master cert while I was turning wrenches for a living. I am available to diagnose your car for less than any shop would charge you. Send me a PM if interested.

Norm, as for the magnum XL, yes, the crossmember is different because the trans is longer. The rear mount is moved toward the rear a few inches. You get a crossmember with the trans. Pinion angle MUST be set, so an adjustable upper needs to be installed. I'm running the JPC shaft, which has U-joints at both ends. If the shaft has a CV joint or double U joints at the rear, that would eliminate the need for pinion angle adjustment.

Ps: I biased my pinion angle @0.7*
 

2010GlassGT

Junior Member
Joined
Oct 27, 2017
Posts
33
Reaction score
1
From what I could tell yesterday, the LCAs and UCA bushing are pretty shot. The LCAs were NOT loosened when I put the suspension kit in, however. The Ford Racing instructions said nothing about this. The driveshaft is the one that comes with the JPC kit, so U joints at both ends. See link in post above. The transmission and crossmember bolts have all been torqued (I've had it in and out twice for a different issue - clutch).
 

oldVOR

forum member
Joined
Apr 9, 2015
Posts
1,746
Reaction score
483
Location
Northern Virginia
Given the diagnosis that your LCA and UCA bushings look shot, I'd say the noise your are hearing is from the axle moving around over bumps and taking a few cycles to calm down.

I'd recommend a set of LCA's and a UCA with mount. My personal preference would be BMR, no affiliation, just well made parts with excellent customer support.
 

Latest posts

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Sponsor Links

Banner image
Back
Top