2013 rear noise (diff maybe)

kwarnerjr

Active Member
Established Member
Joined
Oct 23, 2016
Messages
172
Location
Florida
I've had a number of issues lately so I think my ears may be biased. I remember reading awhile back about differential noise in our SVT GT500's. I recently got a new axle under Warranty and during the Install the Ford Techs had to wait for "guidance" to complete. With that little fact in the back of my mind I thought I heard somewhat of a hum coming from my rear. Maybe they failed to replace or ensure diff fluid was up to par? I attempted to document it with my phone but the hum is very subtle. Since it's subtle I decided maybe I was only hearing it because I wanted to hear a hum. At that I'm gunna turn it over to you guys as I can't decide if I'm searching for an issue that doesn't exist. The cars drivability has been unaffected.

Below is a video of my car on the highway. I think I hear a hum when lightly on accelerator and no hum when off the accelerator.
Thanks in advance


Sent from my iPhone using the svtperformance.com mobile app
 

paluka21

Well-Known Member
Established Member
Joined
Aug 24, 2004
Messages
2,599
Location
Maryland
It's probably just the tolerances of the gear installation. Unfortunately when Ford put in the rear they did in a pig heavy car with over 600ft/lbs of torque, the rears in these cars were bound not to last.
You could always return to the dealer to request shimming the gears, but it's most likely going to end up the same way eventually anyways. (Ask me how I know).
 

Imatk

Well-Known Member
Established Member
Joined
Aug 21, 2008
Messages
2,306
Location
Texas
Yeah I think these things are just noisy :/

I do hear the hum your talking about. I'd take it back just to see if they can fix it... that would drive me bonkers.

I just recently replaced the diff cover on my car ('07) with the 2013 diff cover because of the fins and access bolts.

Now I can hear an audible change in the rear of the car... and the gears weren't touched.
 

fmylife

Member
Established Member
Joined
Feb 18, 2015
Messages
198
Location
Irmo, SC
What gear ratio? I went from stock 3.31s in my '08 to FRPP 3.73s and they whined just like that. Readjusted 2-3 times without any change. Changed to Motive 3.73s, same problem and they readjusted 2-3 times without much difference. Dropped back to FRPP 3.55s and no noise now! I also had a Scott Drake diff cover/bearing girdle installed at the same time and maybe that helped as well.

With my 3.73s, they whined immediately after install, being very easy on the throttle. Didn't beat on them and they made all kinds of noise.

Mine were extremely noisy....louder than your video and also made noise on decel. Someone here mentioned adding another bottle of Ford friction modifier and it actually cut some of the whine. It was still annoying but it could possibly cut yours down to barely noticeable. Worth a shot for how inexpensive it is.
 

RedVenom48

Let's go Brandon!
Established Member
Joined
Sep 29, 2014
Messages
7,973
Location
Arizona
Mine are noisy as hell, just like that. Of course, i have a shitload of passes on em too.... Not to mention all the noise transferring suspension modificationa. So while they might be noisy and out of spec, they havent failed me thus far.
 

SirShaun

Well-Known Member
Established Member
Joined
Jun 9, 2014
Messages
1,392
Location
Virginia
My tru trac with 3.73s chatters, clunks, whines. I'll give it hell until it goes.
 

kwarnerjr

Active Member
Established Member
Joined
Oct 23, 2016
Messages
172
Location
Florida
What gear ratio? I went from stock 3.31s in my '08 to FRPP 3.73s and they whined just like that. Readjusted 2-3 times without any change. Changed to Motive 3.73s, same problem and they readjusted 2-3 times without much difference. Dropped back to FRPP 3.55s and no noise now! I also had a Scott Drake diff cover/bearing girdle installed at the same time and maybe that helped as well.

With my 3.73s, they whined immediately after install, being very easy on the throttle. Didn't beat on them and they made all kinds of noise.

Mine were extremely noisy....louder than your video and also made noise on decel. Someone here mentioned adding another bottle of Ford friction modifier and it actually cut some of the whine. It was still annoying but it could possibly cut yours down to barely noticeable. Worth a shot for how inexpensive it is.

It's got the stock 3.31's, figure I'll go ahead change the fluids and lube everything up and hopefully that solves it


Sent from my iPhone using the svtperformance.com mobile app
 

PistolWhip

Resident Man Dime
Established Member
Joined
May 17, 2005
Messages
6,021
Location
South Jersey
Mine have been somewhat noisy since it was new. It hasn't gotten any worse in 12k miles and gobs of added power, so I'm assuming like the Ford tech told me originally, "it's just a characteristic of these cars."
 

fmylife

Member
Established Member
Joined
Feb 18, 2015
Messages
198
Location
Irmo, SC
It's got the stock 3.31's, figure I'll go ahead change the fluids and lube everything up and hopefully that solves it
Check this out as well.

http://www.teamshelby.com/forums/index.php?showtopic=34907&hl

There's supposedly another TSB doc that said adding another bottle of friction modifier assisted in quieting the gears but I haven't found that one yet. Still worked for me.

I think most people use 75w90 gear oil but I went with 75w140 this time around and I think it's helped as well.
 

kwarnerjr

Active Member
Established Member
Joined
Oct 23, 2016
Messages
172
Location
Florida
Ford Techs said the rear on these cars are naturally noisy. They acknowledged the noise and checked the diff fluid which was normal. They mentioned that I have BMR Lower and upper control arms which (the bushing style) can amplify the noise. Scheduled a more in-depth look at the drivetrain for Wednesday but they think there is probably nothing functionally wrong.


Sent from my iPhone using svtperformance.com
 

RedVenom48

Let's go Brandon!
Established Member
Joined
Sep 29, 2014
Messages
7,973
Location
Arizona
Have them do a contact wear pattern check of the gear mesh, that will show what part of the gear tooth the mesh is at. If its not centered on the ring gear tooth, or the pattern is splotchy and uneven thats your noise.

Backlash also needs to be checked. Too much and it will amplify worn gears throught the diff and cause excessive slop in the drivetrain
 

gimmie11s

I Race Pontiacs
Established Member
Premium Member
Joined
Jun 1, 2004
Messages
18,488
Location
la la land
Shouldn't make a lot of noise with the 3.31s.

My 2014 Gt came with factory 3.73s and they were loud.

Swapped to 3.27s in that car in my garage and noise disappeared.
 

Users who are viewing this thread



Top