7 years later and this video is brining a LOT of peace of mind! I just took delivery of a 39k mile cobra that I purchases sight unseen and was very nervous about the clunk. Glad to know I didn't end up getting somebody else's problem! Cheers!
Thanks again SJ. My Aussie 2002 Mustang Cobra does the same thing. I have replaced everything on the IRS. New diff, gears, diff bushes, cross axis bushes you name it. Only thing left is the diff brace which is on its way from USA. Also I am installing gearbox mount from CJ Pony. 99-04 V8 POLY TRANS MOUNT & CROSSMEMBER KIT EXCEPT 03-04 COBRA. So if it is still 'clunking' after this I am turning the music up louder. Like you said, just get used to it. Will keep you advised. Mine clunks when you let off the gas more. Weird...... Great job as usual mate. I download all your Mustang Cobra vids and put them into my library..... :)
Mine makes the same sound when I depress the gas pedal in a low gear. Figured it was a bushing or something, but the video and forums say it's just normal... Will look into FTBR bushings in the future. Love the videos Danny. ❤Happy Holidays!
It's so funny to look back on this topic! When I first drove my Terminator I thought the driveline was gonna blow right out of the car! lol Especially in the beginning when my Cobra had the real hard pedal (centerforce)clutch in it, the clunk was very distinct. Now with the bushing kit and irs brace along with a light pedal, twin disc clutch(McLeod RXT), the clunk is very slight, but it is an '03-'04 Cobra characteristic for sure!
Yeah, one day I need to do some bushings. I’m a lot more confident now after dropping the IRS for the lowering springs install. Thanks for the comment and your loyal following 😉
I actually fixed this clunking problem by re tightening the bolts that hold the differential in place, turns out they where loose, probably from all that wheel hop I get from trying to make sick burn outs. But owned my Cobra for about a year until my cousin with +10 years working on cars told me that wasn't normal lol
Just finishing build , took out car for the first time, turned around in minutes put it back on lift looking to see something horrible, lol oh it’s normal wtf awesome video thanks dude
Your videos are great man. I just replaced the engine mounts on my 01 cobra I just bought and was really disappointed that I now had a clunk in the rear also to fix, but now maybe not. Mine sounds just like that.
Wow that’s crazy, my car does the same thing. The original owner told me it had some kind of driveline slack that was causing it. My car has a +3 spec clutch in it and I thought it also could have been just violently engaging into gear. Now I know.
My 03 with 10,735miles now, I bought 3 weeks ago with 10,180 miles makes this clunk when starting off in first gear. The seller told me it was the full-tilt boogie rear-end he had put in and was perfectly normal. Lots of forums say it's not normal. I was scared maybe something inside the differential was damage when he installed the Ford Racing cover or something. Mine only does it at take off in first gear and is like a hard solid clunk kinda like the rear shocks are hitting something. Hard to explain really. Lol. Ill ignore it since it runs fine..and you say it's fine. Definitely my go-to guy for advice. 😂
A lot of the 03/04 Cobra’s seem to have a lot of excess backlash (from the factory). Ford recommends .008 -.012 for backlash but many of them rock more than that. Next time you have a chance to have the rear wheels in the air move the driveshaft back and fourth to see how much free play is in the differential. If it’s too tight it will burn up gears, but loose isn’t as bad- still can chip gear teeth with the snapping between gears but I don’t think it’s anything uncommon or to be overly concerned about
Here is my gear install playlist which later videos show the setting of gears and what the backlash should be. If it’s the case and it really bothers you, you can remove the diff (which I also have videos for) and add shims to correct the backlash) ua-cam.com/play/PLIjr-uSYDZi5fnxxp6D9MO7_QlTzizaUf.html
@@dannyjohnsonsgarage definitely what it sounds like....the driveshaft hitting the differential when I go to take off in first gear. I'll look at it when I install my new it's bolts this week. I don't have access to a grinder and have a good feeling I won't have can issue with them. Already bought 2 of the 8mm hex sockets and they fit great in the new bolts. No play at all.
When I got my 03 Cobra I noticed this the first time I drove it. Is this clunk more so after you shift and then get back on the gas? That’s what I’m experiencing.
man you are super lucky to have a screaming yellow terminator!!! I know it feels great. I'm only 17 and I have a 94 5.0 convertible, I absolutely love it. plus its my very first car. oneday I hope to see myself behind the wheel of an 01 bullitt or an 03-04 cobra. you should really do some more rolling videos and drive arounds. your exhaust setup is music to my ears!
My 1999 cobra sounded the same as my 2003. I was worried when I first bought mine and the guy said the same thing " just research it". The worst is when people ask if it's safe to go so fast with that clunking sound. 😂
I got 103,000 on mine and I don't have that problem. Honestly I think it sounds kinda cool, more raw mechanical sound from the gearbox/ rear end. Update: It just started occurring now at 104,000. I took it to East Coast Mustangs in SC for a simple diff leak fix and now the car does this. Is this their fault or what happened.
Mine clunks really bad now after a drag strip wheel hop it does it hard now and more than once in between shifts it sounds bad now I guess my bushing went out when I wheel hopped and found my diff cover was leaking while I was looking under there
Mine is leaking as well. I'm probably buying a Ford Racing diff cover like I have for my Mach 1 (but for IRS) and will have an install video when I do. It's a little more tricky with IRS
Change your gear ratio! My dads 4x4 did that when we changed back the stock tires from big off road wheels, I think the gears are to long so you need a shorter ratio to tighten the rear end to the drive shaft to avoid play, theirs a lot of slop with longer gears. 3.55 or 3.73 would be a good upgrade since these do have long gears 3.29 I think
Jj1303693 the car comes with 3.55s. That's as short as you want to go cause you need the longer gears to stay in boost. I have 4.10s in my Mach 1 and it's hard enough to keep traction at 300 rwhp and this cobra has 600 RWHP.
Update: It just started occurring now at 104,000. I took it to East Coast Mustangs in SC for a simple diff leak fix and now the car does this. Is this their fault or what happened.
have you ever had it on dyno? any problems my shop didn't want to send it to dyno saying something might break just got an 03 drivetrain swapped in my 01 cobra its on my page
Hmmm, I dunno, I still have the oem manifolds and an x-pipe. long tubes don't really add enough power to be worth the trouble, at least on my DD. Someday I'll get around to it.
HoUsT0n23 your car could be misfiring if there’s no check engine then probably not if not it’s just Unburnt fuel in the exhaust long tubes are supposed to help with low end torque supposedly xpipe make it raspy
I did a 2003 cobra engine swap on my 99 cobra now that I’m trying to sell it and real cheap people make a big deal out of that noise. Kinda pisses me off too cuz they want me to lower the price and I’m already selling it real cheap
Hey John. I now hear a squeaking noise coming from my engine pully system when I accelerate and in idle. after a while and the engine gets warm it stops. do you think its time for new engine pullies? I have 103,000 miles on my 04 cobra. thanks.
oolou04 Plancarte very well could be. If they are stock get rid of them! They will explode! If they are aftermarket, check out my billetflow bearing replacement video!
Scrun Johnson Ah, cool. The noise always worried me when I first got my car and never could figure out what was causing it lol. I enjoy all the videos man, very helpful!
It’s not as common on a mach 1 because the mach 1 has the different axle (solid rear axle not independent rear). It’s possible your mach 1 shares some of the issues found on the cobra like having too much backlash in the gears like the cobras, but it wouldn’t be the irs subframe
@@dannyjohnsonsgarage yeah i took it to the mechanic to get it cheked he said everything was fine, motor, transm, fluids the whole 9 yards, i hope its nothing🙏 tha ks for the reply and the great content👍👍💪
Honestly, I feel like the IRS squats a bit better on the street as each wheel can move independently. I haven't had any major issues with wheel hop either. But definitely less worry with my Built SRA.
Scrun Johnson on my 05 mustang gt and my cousins 03 mach1 the solid axles launch so much better than my 2005 GTO, I'm about to get a cobra in the next week or so haven't ever drove one but I hope the wheel hop isn't as bad as the goat
@@dannyjohnsonsgarage thanks for the reply and info. I will look into those possible issues. Also I appreciate your knowledge and videos of the cobra which were really helpful for me when I wanted to know the proper way to jack it up when I was installing lowering springs. Their is lots to learn about these cars...... honestly im still learning things about my GT after owning it for 7 years but anyway keep up the good work.
Scrun Johnson ya bud for sure. Huge termi fan. Unfortunately I put all my money into investment properties so can't right now but will in hopefully 10 years
Danny Johnson if you want to call it that but I’ve driven plenty of cobras and none of them made that noise. I even have a stock irs in my 94. if it makes that noise it is not normal that’s what is sounds like if your bushings are shot or your bolts that hold the diff in are loose. Or bad u joints.
Stinkertits Yeah, it’s a normal occurrence on Cobras. You must be lucky enough not to have it on either while my brother, my friend, and I all have it on our cobras.. or maybe you don’t notice yours ha ha. I can’t believe you haven’t heard of this before if you’ve done so much with Cobras
7 years later and this video is brining a LOT of peace of mind! I just took delivery of a 39k mile cobra that I purchases sight unseen and was very nervous about the clunk. Glad to know I didn't end up getting somebody else's problem! Cheers!
Thanks again SJ. My Aussie 2002 Mustang Cobra does the same thing. I have replaced everything on the IRS. New diff, gears, diff bushes, cross axis bushes you name it. Only thing left is the diff brace which is on its way from USA. Also I am installing gearbox mount from CJ Pony. 99-04 V8 POLY TRANS MOUNT & CROSSMEMBER KIT EXCEPT 03-04 COBRA. So if it is still 'clunking' after this I am turning the music up louder. Like you said, just get used to it. Will keep you advised. Mine clunks when you let off the gas more. Weird...... Great job as usual mate. I download all your Mustang Cobra vids and put them into my library..... :)
Mine makes the same sound when I depress the gas pedal in a low gear. Figured it was a bushing or something, but the video and forums say it's just normal... Will look into FTBR bushings in the future. Love the videos Danny. ❤Happy Holidays!
It's so funny to look back on this topic! When I first drove my Terminator I thought the driveline was gonna blow right out of the car! lol Especially in the beginning when my Cobra had the real hard pedal (centerforce)clutch in it, the clunk was very distinct. Now with the bushing kit and irs brace along with a light pedal, twin disc clutch(McLeod RXT), the clunk is very slight, but it is an '03-'04 Cobra characteristic for sure!
Yeah, one day I need to do some bushings. I’m a lot more confident now after dropping the IRS for the lowering springs install. Thanks for the comment and your loyal following 😉
You're my cobra guru! Keep it up man! Love the videos
I actually fixed this clunking problem by re tightening the bolts that hold the differential in place, turns out they where loose, probably from all that wheel hop I get from trying to make sick burn outs. But owned my Cobra for about a year until my cousin with +10 years working on cars told me that wasn't normal lol
Jaime Almanza nice!
Just finishing build , took out car for the first time, turned around in minutes put it back on lift looking to see something horrible, lol oh it’s normal wtf awesome video thanks dude
Your videos are great man. I just replaced the engine mounts on my 01 cobra I just bought and was really disappointed that I now had a clunk in the rear also to fix, but now maybe not. Mine sounds just like that.
Yeah, it’s pretty common. Can be better, but as long as it’s not a horrible bushing that’s bad and causing alignment issues, just a noise
Wow that’s crazy, my car does the same thing. The original owner told me it had some kind of driveline slack that was causing it. My car has a +3 spec clutch in it and I thought it also could have been just violently engaging into gear. Now I know.
GenAfterNextTactics The 03/04 Cobras do tend to have some extra (loose) backlash on the way they setup the ring gear. it could be part of it
My 03 with 10,735miles now, I bought 3 weeks ago with 10,180 miles makes this clunk when starting off in first gear. The seller told me it was the full-tilt boogie rear-end he had put in and was perfectly normal. Lots of forums say it's not normal. I was scared maybe something inside the differential was damage when he installed the Ford Racing cover or something. Mine only does it at take off in first gear and is like a hard solid clunk kinda like the rear shocks are hitting something. Hard to explain really. Lol. Ill ignore it since it runs fine..and you say it's fine. Definitely my go-to guy for advice. 😂
A lot of the 03/04 Cobra’s seem to have a lot of excess backlash (from the factory). Ford recommends .008 -.012 for backlash but many of them rock more than that. Next time you have a chance to have the rear wheels in the air move the driveshaft back and fourth to see how much free play is in the differential. If it’s too tight it will burn up gears, but loose isn’t as bad- still can chip gear teeth with the snapping between gears but I don’t think it’s anything uncommon or to be overly concerned about
Here is my gear install playlist which later videos show the setting of gears and what the backlash should be. If it’s the case and it really bothers you, you can remove the diff (which I also have videos for) and add shims to correct the backlash) ua-cam.com/play/PLIjr-uSYDZi5fnxxp6D9MO7_QlTzizaUf.html
Differential removal videos ua-cam.com/play/PLIjr-uSYDZi4GVUMK2SdUL74fClSt4-IZ.html
@@dannyjohnsonsgarage definitely what it sounds like....the driveshaft hitting the differential when I go to take off in first gear. I'll look at it when I install my new it's bolts this week. I don't have access to a grinder and have a good feeling I won't have can issue with them. Already bought 2 of the 8mm hex sockets and they fit great in the new bolts. No play at all.
wowi know exactly what your talking about ! mine does it too ! i thought something was wrong ! thanks for the video
When I got my 03 Cobra I noticed this the first time I drove it. Is this clunk more so after you shift and then get back on the gas? That’s what I’m experiencing.
Yes.
man you are super lucky to have a screaming yellow terminator!!! I know it feels great. I'm only 17 and I have a 94 5.0 convertible, I absolutely love it. plus its my very first car. oneday I hope to see myself behind the wheel of an 01 bullitt or an 03-04 cobra. you should really do some more rolling videos and drive arounds. your exhaust setup is music to my ears!
My 1999 cobra sounded the same as my 2003. I was worried when I first bought mine and the guy said the same thing " just research it".
The worst is when people ask if it's safe to go so fast with that clunking sound. 😂
I got 103,000 on mine and I don't have that problem. Honestly I think it sounds kinda cool, more raw mechanical sound from the gearbox/ rear end.
Update: It just started occurring now at 104,000. I took it to East Coast Mustangs in SC for a simple diff leak fix and now the car does this. Is this their fault or what happened.
FTBR FTW!
Mine clunks really bad now after a drag strip wheel hop it does it hard now and more than once in between shifts it sounds bad now I guess my bushing went out when I wheel hopped and found my diff cover was leaking while I was looking under there
Mine is leaking as well. I'm probably buying a Ford Racing diff cover like I have for my Mach 1 (but for IRS) and will have an install video when I do. It's a little more tricky with IRS
dude i have all new parts in mine and it still does it. i was worried my gears had too much backlash.
That could be very possible. They seem to be set pretty loose on the cobra’s
my 03 does the same, doung a bushing kit in the spring
I don't hear mine... but is a fully built irs but I do hear a clunk in the trans
brian butrico the t56 is notorious for that as well, but usually in 1st gear
I hear it in almost every gear
So the clunking is from the “ give “ in the bushings ? Thanks so much !
Yeah, bushings, a little extra backlash the cobras seem to have, subframe bolts etc.
Mine is less pronounced with upgraded diff bushings (I used the MM ones)
powerviking nice
My 2002 Cobra does the same even after new diff and gears, bushes ect ect. Not as bad as yours though Danny.
yeah, mine is all stock
I have a 01 gt it has irs, from what I have read this car only came with straight axle rear ends. I'm guessing somebody swapped in a cobra irs?
natesv04 Yes, it must have been swapped. I have videos on pulling the differential, axles, etc
natesv04 ua-cam.com/play/PLIjr-uSYDZi4GVUMK2SdUL74fClSt4-IZ.html
Change your gear ratio! My dads 4x4 did that when we changed back the stock tires from big off road wheels, I think the gears are to long so you need a shorter ratio to tighten the rear end to the drive shaft to avoid play, theirs a lot of slop with longer gears. 3.55 or 3.73 would be a good upgrade since these do have long gears 3.29 I think
Jj1303693 the car comes with 3.55s. That's as short as you want to go cause you need the longer gears to stay in boost. I have 4.10s in my Mach 1 and it's hard enough to keep traction at 300 rwhp and this cobra has 600 RWHP.
Update: It just started occurring now at 104,000. I took it to East Coast Mustangs in SC for a simple diff leak fix and now the car does this. Is this their fault or what happened.
have you ever had it on dyno? any problems my shop didn't want to send it to dyno saying something might break just got an 03 drivetrain swapped in my 01 cobra its on my page
Yay your cobra pops at idle like mine i thought mine was misfiring or had a leak
YES they all do that unless maybe if it has long tubes
powerviking longtubes stop that?
Hmmm, I dunno, I still have the oem manifolds and an x-pipe. long tubes don't really add enough power to be worth the trouble, at least on my DD. Someday I'll get around to it.
HoUsT0n23 your car could be misfiring if there’s no check engine then probably not if not it’s just Unburnt fuel in the exhaust long tubes are supposed to help with low end torque supposedly xpipe make it raspy
Pablo they all pop
I did a 2003 cobra engine swap on my 99 cobra now that I’m trying to sell it and real cheap people make a big deal out of that noise. Kinda pisses me off too cuz they want me to lower the price and I’m already selling it real cheap
Forget them lol. The right buyer should come around
Did you ever resolve this clunk or just learned to life with it?
I just live with it. It doesn't bother me enough to redo all the factory bushings on the car since it only has 44k miles.
Hey John. I now hear a squeaking noise coming from my engine pully system when I accelerate and in idle. after a while and the engine gets warm it stops. do you think its time for new engine pullies? I have 103,000 miles on my 04 cobra. thanks.
oolou04 Plancarte very well could be. If they are stock get rid of them! They will explode! If they are aftermarket, check out my billetflow bearing replacement video!
Mine doesn't clunk at all at 56k miles convertible too all stock besides catback and xpipe
What about the 99/01's? I swear mine has the exact same noise
They likely do. I just am not as familiar with 99/01 so I didn't mention it.
Scrun Johnson Ah, cool. The noise always worried me when I first got my car and never could figure out what was causing it lol. I enjoy all the videos man, very helpful!
Thanks! Is that an electric green Cobra then? I love electric green!
Scrun Johnson It is, thank you! I very rarely see any. Every once and a while I'll run across one on the internet, it stands out some haha.
My mach1 does that too from time to time, is it normal on a mach1???
It’s not as common on a mach 1 because the mach 1 has the different axle (solid rear axle not independent rear). It’s possible your mach 1 shares some of the issues found on the cobra like having too much backlash in the gears like the cobras, but it wouldn’t be the irs subframe
@@dannyjohnsonsgarage yeah i took it to the mechanic to get it cheked he said everything was fine, motor, transm, fluids the whole 9 yards, i hope its nothing🙏 tha ks for the reply and the great content👍👍💪
how do you like the mach1s solid axle compared to the irs
Honestly, I feel like the IRS squats a bit better on the street as each wheel can move independently. I haven't had any major issues with wheel hop either. But definitely less worry with my Built SRA.
Scrun Johnson on my 05 mustang gt and my cousins 03 mach1 the solid axles launch so much better than my 2005 GTO, I'm about to get a cobra in the next week or so haven't ever drove one but I hope the wheel hop isn't as bad as the goat
just get out of it if she hops or it will snap lol. You know that I'm sure. Congrats on the Cobra purchase if it goes through!
No such noise in my 03 Cobra at all ???
Yeah, it all depends on how much freeplay the IRS has. Its fairly common. How many miles does your cobra have on it? Has the IRS had maintenance?
Man mine has it bad. When I jump off the gas and ez back on it, it clucks.
Brian Poaches Time for new bushings or even check the diff for too much backlash (pretty common on the 03/04 cobras for some reason)
@@dannyjohnsonsgarage thanks for the reply and info. I will look into those possible issues. Also I appreciate your knowledge and videos of the cobra which were really helpful for me when I wanted to know the proper way to jack it up when I was installing lowering springs. Their is lots to learn about these cars...... honestly im still learning things about my GT after owning it for 7 years but anyway keep up the good work.
Brian Poaches No prob. Thanks for watching my videos 👊🏼
fuckin nice car man! ONE DAY
Horse From Hell thanks. Check out my other videos of the car if you haven't seen them ;)
Scrun Johnson ya bud for sure. Huge termi fan. Unfortunately I put all my money into investment properties so can't right now but will in hopefully 10 years
That's odd????? Mine doesn't have the clunk lol 40k miles bone stock irs
Brett Rice you're lucky lol. Mines 42k with the clunk lol
Not normal at all. Just bad bushings
Normal for how these cars are put together
Danny Johnson if you want to call it that but I’ve driven plenty of cobras and none of them made that noise. I even have a stock irs in my 94. if it makes that noise it is not normal that’s what is sounds like if your bushings are shot or your bolts that hold the diff in are loose. Or bad u joints.
Stinkertits Yeah, it’s a normal occurrence on Cobras. You must be lucky enough not to have it on either while my brother, my friend, and I all have it on our cobras.. or maybe you don’t notice yours ha ha. I can’t believe you haven’t heard of this before if you’ve done so much with Cobras