View Full Version : too much power,,,distroyed drive shaft,,,help!

Dave B.
09-28-2005, 08:12 PM
I have a lot of stuff done to my 03 Cobra, when we put 4:10 gears in it, we arlso learned the amuminum drive shaft had been wreacked due to the amout of HP im making, is there a fix for this? the carbon fiber shafts are not availible right now, we had a steel shaft made but it vibrates like a mother,

has anyone had this problem and is there a fix ???

09-28-2005, 08:19 PM

Try these two places. They are both vendors for the club and should have the carbon fiber drive shaft available for you. But they are expensive!

Good luck, and let us know how you like it. :thumbsup:

Dave B.
09-28-2005, 08:38 PM
well, thing is im not racing the car, i hate to spend that much for one of those i had a steel one made and was told that would solve my wear problem, but it vibrates like hell, and they cannot take the vibration out

09-28-2005, 08:47 PM
From what I've read and learned the vibration is worse going from steel, aluminum, and then the carbon fiber.
Though you will have some vibration, you can change and adjust the pinion angle to try to smooth out the vibration.
The carbon fiber drive shaft is an expensive peice, but is lighter and will reduce or completely eliminate your driveline vibration you are feeling.

MM has a kit to adjust the pinion angle which helps in reducing driveline vibrations: http://www.maximummotorsports.com/irsdiffmounts.asp

Maybe someone else that has had this problem will jump in here and add some info.

Dave B.
09-28-2005, 08:57 PM
If I read you right, your saying a steel shaft, is going to vibrate worse than a Carbon shaft?

are you also saying, that the problem is compleatly in the Pinion and NOT the drive shaft so much? that its Pinion angle thats causing a drive shaft type vibration?

09-28-2005, 09:21 PM
It's not really that the driveshaft will vibrate more, but the steel drive shafts have a tendency to have more vibration. If the pinion angle is set-up correctly then any driveshaft you have will not have vibration and will drive smoothly:thumbsup:

Dave B.
09-28-2005, 09:42 PM
I just got off the phone with the Mech about the pinion angle deal,,and he is sure its set right, it is for sure the shaft, I have the vibration at about 88 MPH wheather accellerating, slowing down, in all conditions, the drive shaft is ballanced also,

09-29-2005, 01:11 PM
PST makes some of the best driveshafts www.pstds.com (http://www.pstds.com) . I would not recommend carbon fiber, personally....But the make very good aluminum & chromoloy drive shafts.......

09-29-2005, 02:17 PM
how'd you destroy it? launching?

Dave B.
09-29-2005, 08:49 PM
NEWS FLASH!!,,,,,,I am told that there are NO Carbon Fiber drive shafts to be had,,,,I have been told an aircraft corp, has purchased up all the Carbon Fiber in the country,

Does anyone know for sure any place that ha new ones for Cobras for sale?
does anyone have one on there car and did it help the vibration problem?

09-30-2005, 10:28 AM
Actually it's the military suppliers that are using all the CF. Darn Iraq mess.

09-30-2005, 03:55 PM
Try http://www.markwilliams.com/ they custom make drive shafts for race cars.


Dave B.
10-01-2005, 12:00 AM
I GOT ONE!!!!!:banana: :banana: :banana: :banana:

PST has assured me I would have one of their Carbon Fiber shafts made and sent to us by Wednesday of next week, (Oct 5th) they said it should solve my vibration problem, however I am still reeling from the worst mistake iv made in a long time which was taking the 4:10's out and replacing them with 3:73's

I thought the 4:10's were making my shaft spin too fast thus causing the vibrations, I also thought the 3:73's would only make a small power differance but believe me now and hear me later, DONT DO IT!!

the 3;73 gears feel mostly like the 3:55's all that great neck breaking torque is gone, especialy since im running an off road "X" pipe (no back pressure)with long tubes that huge bottom end engine torque is not there only the top end HP, so now once I put this carbon drive shaft in, go out and run up to 140 MPH to make sure the vibrations are gone, its another $400 labor to put my beloved 4:10 gears back in, ouch!! :bawling:

10-01-2005, 10:41 PM
congrats...too bad you're not up here...we'd put them in for $250 :thumbsup:

Dave B.
10-01-2005, 10:58 PM
Thanks anyway, but I have a shop here thats really been dedicated to my car, they have done all the work on it from Day one except for the Cobra "R" wing and hood as they dont do bodywork, Hopefully this Carbon shaft solves the vibration problem, I put up a post asking anyone here if they had one and I just cannot beleive no one on this Forum has a Carbon shaft, but I guess not,

Im still kicking myself over changing out my 4:10's and putting those STUPID 3:73's in,,,,,,I really thought it was only going to move the drive shaft vibration point higher as it would have slowed down the shaft's RPM

I just cannot say how much of that hard hard 4:10 pull it took away, HUGE
wish they made a 3:90 gear set that would have really been great

10-03-2005, 12:55 PM
I have heard of people with carbon driveshafts having problems keeping them balanced.....There are some threads over on Modularpowerhouse.com from Dave Lewis (GI Joe)...Good luck with yours.......I'll stick with the aluminum.....

Dave B.
10-03-2005, 05:59 PM
I think Im making too much power for Aluminum, you should see the bearing holes at the end of my OEM shaft,,,,looks like an egg, the aluminum just cannot hold up to that steel bearing end cap that fits in it, amuminums softer than steel,,,,,,steel wins that fight every time,

I wish I had another option, the only hope I have is the fact the carbon shafts are rated for 1500 HP,,,,,Im only pumping just over a third of that thru it,,,PST assured us it would hold its balance, thats all I can do at this point is trust what they say,,,,,,one must pay,,,,to play

10-03-2005, 08:51 PM
Hope everything works out for you! Keep us updated as to what comes of the new driveshaft. :thumbsup:

10-04-2005, 09:14 AM
They run alum shafts in NHRA pro stock, not allowed to use carbon ones be

cause they had a bunch of failures. To make the alum shaft stronger you go with a larger diameter tube. 4130 steel works well also that's what we have in our 81 z28 that has a 632 that dynoed 1170 hp at the engine shop, works great without any problems.

Dave B.
10-04-2005, 01:59 PM
if you would have read my first post that started this thread, you would see that I had to have a steel shaft made, it was done by a very reputable drive shaft company here, its perfectly balanced, we've tested it three times now, we've clocked it changing shaft positions on the flange, it still vibrates like hell soon as I get to 85MPH and just gets worse the faster I go,

I have spoken with several shops that deal with Cobras, the ones that have had cars come in with vibration problems after doing gears, they put carbon shafts in them, PST them selves tell us this is the fix, what more can we do?

to date I bet the shop and I have spoken with 10 people in the know about this problem, every single one of them had no other solution, the carbon shaft is the only constant in the discussion.

The other thing we'er finding out about these cars is this,,the IRS has something to do with this drive shaft vibration, cars with a a solid axil do not have this problem, its got something to do with all those lightly sprung components in the back of my car, I think its all balanced for the OEM aluminum shaft, then we come along and put this heaver steel shaft in it,

I feel now after all we've heard, that you simply cannot spin a heavy shaft with the IRS,,,,,

Dave B.
10-06-2005, 07:23 PM
My Carbon drive shaft is in and is sitting at the shop,,,its aahh,,,very nice!!!

Ill get it put in the car Saturday afternoon and let you all know what it did to the vibrations. :bounce: :bounce: :bounce:

10-07-2005, 08:46 AM
so you bought a carbon driveshaft b/c of vibrations above 80mph? just wondering b/c there are KB cars still running the stock driveshaft with no problems...either way, good luck and let us know how it turns out :thumbsup:

Dave B.
10-07-2005, 01:48 PM
I know we dont understand why, my car without a KB or a wipple, egged at the shaft end bearing holes, I have asked a lot of people about this, no one has an answer of "WHY"

The one thing I would ask these guys with KB or wipples, that are running stock gears, to go out some where and run the car up to about 120 MPH and see if they do not have a WOORBLE SOUND and have their rear veiw mirrors vibrating so bad you cant see anything,

I would have never known I had a problem if we would not have put the 4:10's in, when we did that, it caused the shaft to be spinning much faster at lower speeds, its all just a puzzle, all I know, is this is how others fix the problem, one thing I will add though, is i did not put headers on until recently, with the stock manafold my car had huge giant low RPM bottom end torque that could had damaged where these other guys with KB's would have been making more top end power,,,,heck I dono,,,,,

10-07-2005, 06:47 PM
Good luck with the shaft, I have been contemplating buying one as well. I running about 485rwhp, and 542 rwtrq, with stock gears. And I too have vibration starting around 75 to 80, and then it increase with speed. Let us know how it turns out! And if you ever want to sell your 410, you let us know too! ;)

Dave B.
10-07-2005, 06:50 PM
when your going about 90+ does your rear veiw mirror vibrate and smear the image in it? how many miles on the car since you have been making big power?

10-07-2005, 09:28 PM
I have an 03 redfire coupe that is all stock except fot KN filter and boost bypass. I'v been reading this post for a while,and never really thought about it TILL I made a trip to Greensboro NC ( about an hour trip) When I realized I felt it TOO vibrating from about 80 and up. The faster I went the worst it felt. ALSO now that I thing about it. It did the some thing in my 95 GT??? I just figured it was tires I don't know?? Another thing I'm woundering is if my car HAS 3.73's. I was reading a 5.0 mag. and they said that with 3.73 @ 75 2200 RPM's in 6th gear and that is about what mine reads. Does anyone know what their RPM's are supposted to be with 3.55's @75 in 6th gear??????????? I bought the car feb.19th with 8900 mile's with visibly no-mods> BUT rear end was leaking then I took it to ford for a noisy throw-out bearing. Any info would help out thanks

Dave B.
10-07-2005, 11:01 PM
I would like to suggest to all of you 03-04 Cobra people that are making some decent horse power, to go out on a long barren road and get up to about 120 MPH or so, if you have gears it will happen at a much slower speed, and look into your rear veiw mirror, if it looks all squiggly and you hear and feel WOORBLING sound.

Then whats happened is the steel round bearing end caps (i dont know the official name for it) they fit into these two end flang peices made out of aluminum have over time and romping on it ovaled out the aluminum to the point its moving and is no longer balanced, some of you will find that your shaft is done for, mine when we first realized it, sent the shaft to a drive line shop and they were able to fix it but they were clear that it would not last, sure enough,,about 300 miles was all I got,,,,ITS TRASHED!!!

im afraid if your making power, your going to be needing a Carbon shaft too.