What's the deal with shift "clunk"?

[mu22stang]

It's the Mustang clunk that's amplified by the Diff being bolted to the frame in the IRS. Billetflow IRS Brace and stiffer bushings may make the clunk worse - best advice is to get used to it. My 14mm bolts did nothing to the clunk, IRS brace did nothing to the clunk, MM Diff bushings did nothing to the clunk, but new transmission fluid and diff fluid made the clunk worse. It's in the drivetrain itself, somewhere...

 

[Nsan3Stang]

i just bought an 04 cobra with 24k miles on it and it does it perdy loud, from what i hear they all have it, it bugged me at first but after hearing everyone has it, i got over it

 

[hotcobra03]

diff mounts

My car clunks ever since I got the IRS swapped into it. I have the DSS level 5's with the upgraded inner CVs and Bruces bushing kit on the car. The whole diff was just rebuilt with a new differential, gears, bearings, seals, etc. The clunk still persists.

Now, we believe the clunk to be the rear differential mount bushing. Maybe I missed that one when installing Bruce's kit...I don't know...but I'm going to be trying another one of Bruce's bushings for $45 to see if it solves the problem (one of these days). If not, then I'll try the Billetflow IRS subframe mount pieces as that is another area that could possibly be causing the clunk (along with larger bolts).

i read on one of this sites that someone now is selling the rubber mounts less than before..when i was at ford finding them my first time they showed me that they have 2 different rear housing bushing,,, its a stock style but changes pinion angle,,,ford found a problem thier,,

 

[tonys87]

i also have this problem

I just bought a 04 with 56k miles still under factory warrantee.. after driving it I thought there was something wrong with it because of the clunk,spoke with two friends that also own cobras. They also said it was normal but it still bugged me, so being it still had warrantee I just took her in to get checked. They tore down the rear end and found that it needed ring and pinion in the rear.. ill update after I get the car back to see if that was the problem.

 

[IUP99snake]

It's called "The Cobra Clunk". It's a hollow sound as if something's banging or tapping up against one of the exhaust pipes.

 

[desert_gypsy]

get some grade 8 9/16" bolts to replace the 12mm bolts in the front IRS subframe mounting points. Much of the clunk comes from the play there. The rest of it is diff movement due to crappy rubber bushings and driveline lash. The majority of the clunk is those two subframe bolts, though.

 

[NateTermi]

turn your music up.

exactly what I do...

 

[DocButters]

The bushings fix it?

 

[tonys87]

clunk fixed

Well, I got the car back from the dealer. They replaced "gear and pinion" and insolators.. that's what the paper work says.. car feels super tight with no clunk at any point in time. I'm super happy,cause that crap really buged me.

 

[gamebred26]

to me it sounds like driveshaft slack...mine does it to...when going in to first some times...but have it super tight may night be a good idea...

 

[STAMPEDE3]

To the new guy who bumped this thread,

1. go read the rules.
2. Go check your email. That name will not fly here.