Thud from rear/d.s. area when cold on 07 GT manual

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northy_polk

New Member

Jan 9, 2007

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Aug 20, 2007

#1

• Aug 20, 2007

• #1

i've searched around with no luck. i have an 07 GT 5spd. when i first drive the car in the morning, or after it has been sitting for a while enough to cool off completely, i hear a very pronounced "thud" like the driveshaft is hitting the area around it. this can when shifting from first, second, and third gears. it occurs for the first 5-10 minutes of the drive, but completely disappears once the car is warm.

it is not that i just can't hear it anymore, it actually goes away.

the car is on steeda sport springs and i have spohn adjustable LCAs. i have properly [OR SO I THOUGHT] adjusted the pinion angle. it is not the exhaust hitting the underside because the sound is wrong. it may be the poly bushings on the forward ends of the LCAs [rear ends are spherical].

anybody have this problem or have a solution?

thanks!

 

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homebrewer

Member

Nov 12, 2006

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Richmond VA

Aug 20, 2007

#2

• Aug 20, 2007

• #2

I'm not sure if I'm hearing you right, but I also have a slight thud when taking off cold. After the start up, I'll pull off in first, and then as soon as I push the clutch in, I hear a slight thud/clunk from the rear. Once I shift into second, everything is fine, and I don't hear it again until the next time I run the car cold. Outside temp, shift point, etc seem to have no effect on it.

I'm completely stock, and don't worry about it much. But it sounds like yours may be a bit more complicated. The only thing I could think of is a wider aluminum driveshaft hitting the tunnel while lowered, but you don't seem to have one.... so I'm at a loss.

 

SpartaPerformance

10 Year Member

Nov 5, 2006

2,517

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89

Long Island NY

Aug 20, 2007

#3

• Aug 20, 2007

• #3

It could just be the driveshaft hitting the rear differential, it happens manuals make all sorts of clunking at knocking noises. I've heard them and even other noises if i'm next to cars and it echoes. Also if your lower control arms are adjustable then it might be them usually adjustable control arms have what is called a Hym-joint (dunno if i spelled it correctly) Those always make noise because it actually has a 360 degree functional angle.

 

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northy_polk

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Jan 9, 2007

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Aug 21, 2007

#4

• Aug 21, 2007

• #4

you may be right on the adj LCAs. i do have the spherical rod ends on one end and the poly bushings on the other. this morning i slid a bit taking off around a turn and got a similar sound to the one i was describing. sounded like 'something' related to ds/axle/LCA/LCA lowering brackets/etc. maybe i just won't shift hard for 5 minutes and just worry about the other problems i have with the car 8-(

 

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myfirstii

Founding Member

Feb 28, 2002

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chicago,Il.

Aug 21, 2007

#5

• Aug 21, 2007

• #5

I also have the thud/clunk when i start off cold and begin to shift into second As homebrewer stated. Is this normal? This is my first manual car but i have driven many others and have never experinced this before. Btw It is a 07 Gt 5spd.

Pat

 

stang8urimport

Autozone Junkie

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Jun 21, 2002

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Daytona Beach, FL

Aug 22, 2007

#6

• Aug 22, 2007

• #6

I have the same problem. Dealer tried to fix that and my gear whine many times, and finally told me it was "normal". When I had my 4.10s installed the thunk went away, but then came back after a couple hundred miles. I'm just so sick of my rear axle problems right now I want to sell the damn thing.

 

mustangmike6996

5 Year Member

Nov 10, 2005

483

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29

clinton twp, MI

Aug 22, 2007

#7

• Aug 22, 2007

• #7

OPERATING AS DESIGNED

what you are hearing (to the best of my knowledge) is basically the transmission still spinning due to the motion of the input shaft and it clunks the gears when shifiting.... sounds like its coming from the final drive gears... normal with almost all manual transmissions....

 

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northy_polk

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Jan 9, 2007

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Aug 22, 2007

#8

• Aug 22, 2007

• #8

you could very well be correct. . . it's just that i'm 99.9% positive the sound is coming from the rearward end of the driveshaft. it isn't under the center console, but more like between the middle of the rear seats. and it's after the shift, when i take my foot off the clutch and accelerate, not mid-shift. it's right as i hit the gas that it thuds.

 

93GrunT

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Dec 17, 2000

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NC

Aug 22, 2007

#9

• Aug 22, 2007

• #9

I was reading somewhere that a carbon fiber DS will clear the problem up to a certain degree however, I have not heard any competent reviews done outside of merchant claimed results to support this. I doubt I will be going out and spending 600-900 bucks to find out anytime soon either, I guess I will just listen to it for a while.

 

mustangmike6996

5 Year Member

Nov 10, 2005

483

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clinton twp, MI

Aug 22, 2007

#10

• Aug 22, 2007

• #10

93GrunT said:

I was reading somewhere that a carbon fiber DS will clear the problem up to a certain degree however, I have not heard any competent reviews done outside of merchant claimed results to support this. I doubt I will be going out and spending 600-900 bucks to find out anytime soon either, I guess I will just listen to it for a while.

Click to expand...

i dont see it getting rid of the problem just muffling it due to not being metal... IMO

 

stang8urimport

Autozone Junkie

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Jun 21, 2002

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Daytona Beach, FL

Aug 22, 2007

#11

• Aug 22, 2007

• #11

mustangmike6996 said:

what you are hearing (to the best of my knowledge) is basically the transmission still spinning due to the motion of the input shaft and it clunks the gears when shifiting.... sounds like its coming from the final drive gears... normal with almost all manual transmissions....

Click to expand...

You can tell you're a Ford (or some other Stealership tech) with that "operating as designed" bull ****. That's your companys way of getting out of having to fix a ****ty product. EVERY vehicle I have owned has been a manual, and NEVER have I heard this thunking noise EVER. My 90 has the ORIGINAL tranny and motor, and rear end... And has all spherical rod ends out back and it has never ever made this noise in it's 108,000 mile, almost 18 years in exsistance.

 

SlideWRX

Member

Jan 8, 2007

126

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16

Westland, MI

Aug 23, 2007

#12

• Aug 23, 2007

• #12

northy_polk said:

you could very well be correct. . . it's just that i'm 99.9% positive the sound is coming from the rearward end of the driveshaft. it isn't under the center console, but more like between the middle of the rear seats. and it's after the shift, when i take my foot off the clutch and accelerate, not mid-shift. it's right as i hit the gas that it thuds.

Click to expand...

Maybe the middle joint of the two piece driveshaft?

Tom

 

N

northy_polk

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Jan 9, 2007

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Aug 23, 2007

#13

• Aug 23, 2007

• #13

ahhhhhh! now that is a good theory. i honestly forgot that this has a 2 piece. and the sound is more from the joint area than the very back of the driveshaft. so, what does that mean? did i screw up the pinion angle? i think it's set at minus two or three degrees [does that make sense?] with the driveshaft being at more of an angle up than the flat part of the pinion housing from where the other msrmnt is taken.

 

CRoberts91

Member

Jul 10, 2007

148

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18

Northport, AL

Aug 23, 2007

#14

• Aug 23, 2007

• #14

I think i'm hearing the same noise, although i think its just my transmission. when i head out in the morning i hear a thud when i shift into 2nd. i think its just the actual tranny and after that first 2nd gear shift i dont go into 2nd for another 6-7 minutes. and then when i do, its gone. i think its just because my car isnt warmed up. oh and i do have a manual