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Issue with DSS drive shaft

28K views 85 replies 33 participants last post by  TennesseeGator 
#1 ·
We had an issue yesterday when installing the DSS aluminum drive shaft I wanted to make people aware of, the shaft was perfect,it's the 8 bolts that are used to attach to the rear that are a problem. We started to torque down the bolts and the second bolt failed at 40 ft lbs of TQ, so we took all 8 out and replaced them with the next grade up and finished the install in about 30 min, a call will be made to Frank to make him aware of the issue today. Off to the track to test the shaft this morning:)
TC
 
#3 ·
That's pretty scary if they are sending cheap hardware. What is torque spec? What size bolt? I'm assuming it was an 8.8 and you replaced it with a 10.9?
 
#8 ·
DSS has been made aware of the issue and Frank said he will call Bruce @ HHP to get his thoughts and a few pictures of the failure, looking at the bolt there was not much left where the head meets the threads and the failure was the head coming off.
 
#12 ·
Do we know if this issue was fixed? I just received mine yesterday.
Funny I must have been in the same batch as you. I got mine yesterday too.
Got mine through Dr.B

Have a shop install.
My local Mopar shop specialists are charging me like $325 to install both aluminum DS and my catback exhaust this Friday.
For that, not worth dealing with it myself, and worrying about whether or not any mistakes are being made.

And as I posted a few posts up back in April, this is why I usually wait a bit before buying something that could fail or not perform properly and have serious results because of it.
TC back in April stated they made them aware of it. I'd think they'd of made the changes on the very next batch, back in April. A lot of people have gotten an aluminum DS since then and not one has mentioned this issue since that I've heard of.
 
#10 ·
I can't say if the bolt was changed, post up a picture if you can, as far as dropping the exhaust no if you have a lift, unhook the two rear fasteners and unplug the cutouts, support the two pipes and let them hang a bit down so you can work around them, if working on the floor it will be easier to drop the entire system.
TC
 
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#14 ·
I called DSS and told them my plans and they said aluminum for me.
 
#20 ·
A typical Allen head cap screw bolt is only a grade 2 rating. For the torque specs and load you need, I would suggest buying a hybrid bolt made out of 17-4 kph. The are several companies that make this grade of bolt for the aerospace industry. Hi strength and no corrosion.
 
#24 ·
I think the CF is 4 lbs lighter, and either 3.5 to 3.75 inch diameter. I will check today. The fear is the 300 degree heat limit, but *maybe* only on the bonded ends of the CF shaft, not the other parts since they are very close to the exhaust.

People who probably know more tell me not to worry...and yet I do. Exhaust by/at the cats just sitting there idling with the A/C on is 300-350F, can't imagine after several runs. Exhaust pipes and muffs run 130-170F degrees. The inner reflective heat shields also approach 300 degrees. All that heat reflects, and needs to go somewhere.

I wish more folks had more info; a lot of this is elusive :(
 
#25 ·
Check, because the shipping weight on the aluminum shaft said 29 lbs. I picked it up put it on my digital scale and it said 28.8 (we know shipping companies round up when it comes to weight).
It's in a two piece box, with a protective cardboard piece around it too, tape, and so forth.
That box and such probably weighs 1 lbs or so at most.
So that would put the aluminum one at 27.5-27.8 lbs.
Driveshaft shop lists the CF one at 25 lbs. But they also list the aluminum one at 25 lbs (which I think is a typo since they probably entered the CF shaft's weight in the aluminum shaft's info)
So if the 25 lbs is accurate for the CF shaft, it would be about 2.5-3.0 lbs lighter.


I'm not sure about the heat rating for CF, but that's the nice thing about aluminum, it withstands a lot hotter temps than steel or many other metals. So though it's really close to the exhaust and I was thinking about that too. Then I remembered with aluminum it doesn't get nearly as hot like other metals (hence you can often touch aluminum foil that comes directly out of an oven that was at 400 degrees).
 
#26 ·
Just received and installed my AL DS and had no issues with the bolts provided. They must have upgraded what they are providing.
 
#27 ·
I have a question. The people that are having the drive shaft problem primarily M6 or also the A8. I am hoping the issue is the imediate transfer of energy due to the dumpimg of the clutch? With the A8 you would already have some degree of torque already applied. Am I thinking wrong, looking for some insite before I order the DS.
Thanks
 
#36 ·
Noise. IT was getting worse, and when I added the CF DS it got REALLY LOUD.

I want bigger bolts too. I am hoping TC will chime in, or I will just PM him.
 
#40 ·
I'm really wondering if the aluminum (or in your case the CF) drive shafts are magnifying the diff's noise?
It's weird that your rear diff whine got louder to you with the CF DS as I noticed mine after the aluminum DS (or maybe not any louder but we just hear it more because it may be getting a megaphone effect).

When do you go in for a new diff? Let me know how it goes afterward too please.
Are you worried about the CF DS and them blaming it for the noise? I know that would be tough as plenty of proof on here that even without an aluminum or CF DS, people have the diff whine.

It would also be interesting to test the level of noise from the diff with a stock DS vs the aluminum or CF DS
 
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