Tuomas FIN

What happened, any recommends for new ones??

Tuomas FIN

Threads in aluminium driveshaft on rear side has broke up.. Reason, dont' know.

DSS couplers and new housing ordered.. New DSS driveshaft arrived few days ago.

JMBLOWNWS6

All I can think of is the poly bushing deformed with heat. That gave the metal bushing and bolt room to flex and the aluminium being the weakest link sheared and broke your shaft.

Tuomas FIN

Am I only use these? Noone has been any problems??

Turbo-Geist

For high power, track oriented applications, I would get rid of the couplers altogether. You can either choose a DSS carbon fiber driveshaft or Pfadt carbon fiber.

I chose the DSS and will never have to change couplers again.

BoosterClub

If I am looking at that correctly the urethane is clamped by the bolt? Do you have some detailed pictures of one in good condition? In a sheer situation the bolt has to be torqued against and through a solid surface. Any lash hugely compromises the integrity.

Turbo-Geist

I would guess a cyclical fatigue failure. It looks like you were using a stock driveshaft, but I'm not sure how much power you are making. At high sustained engine rpms, the shaft has a small whipping motion or "jump rope" effect. This is transferred through the couplers. In this case, it looks like the repeated cyclical load caused the polyurthane to break down. This caused the internal clearances to increase in the bolted connection which allowed even more movement until the failure occured.

As mentioned before, there are a few different solutions. A driveshaft with a larger moment of inertia via increased diameter may reduce the harmonic oscillations to a point that is manageable with stock couplers. Many people see the couplers as a wear item. When you look at the amount of work involved to change them out and the cost to buy new ones a few times, it made more sense for me to go ahead and purchase a carbon fiber driveshaft and do away with the couplers completely.

Tuomas FIN

Hmm. that sounds reasonable. Yes stock shaft and making 630 rwhp and like to drive a lot on race track.
I'm trying to brake after will get new long block 1 K rwhp and don't know power rating of carbon drive shaft.. Now moving to 3,5" DSS shaft and DSS couplers.

crazystevex

Would a carbon fiber drive shaft be suitable for daily driving? on a stock car? Just curious. I think my couplers are wearing out too.

0Rob@ChampionMotors

We install many of these most in 1000+ rwhp corvettes. Just make sure the Guibo is sitting flat when installed as we had to grind inside edge of guibo washers to sit flat.

Josh@AandASuperchargers

I've run these on several high power boosted vettes and they work great, unless the car does road course track days. ie- 25+ min sessions and the heat inside the torque tube will cause it to melt and scatter just like that. None of the street cars, drag cars, roll race, standing mile cars ever melted one, just the road course cars.

I prefer the GM/BMW rubber coupler up front and a billet alum rear for my personal setup.

Heavy Dutys Germany

Hello Over there !
We had close the same problems with the Couplers.
I would say . heat is one problem for shure.
Otherproblems are :
The contakt face ( Outside diameter ) of the aluminim Bushings to the shaftside and the driveflanshes is to small .( look on the shaft where the treats are in..you will see a compressed aira from the old oem coupler as well from the Prothane sleeves )
The commpressing reduces the stretch of the bolt..the bolt gets loose and so on..
I also would say there is also a steel shim missing between the shaft and the
Poly-bushing...so the Bushing is not able to sit real flat against the ears
of the shaft and is able to walk out to the outside....
I mashined the shaft some tens o a millimeter to have a clean surface...
I will shorting the Aluminium Coupler Ring to allow the use 2 halfes
of selfbuild mushroom bushings build from 42 CrNiMo 6
I also will use different bolts with a shaft what has on 32mm from the head-side no tread to aligne the bushings better and to protect the inside of the bushings better from the sharp treads

We test that this Month in SPA Belgium

Hope this was interesting for you !
By
Rainer @Heavy Dutys Germany

redline06

heat, shock loads, and good traction will break most driveline parts