Hi everyone!

I have a '99 with the 10mm bolts. Do I need to swap out the entire torque tube or just the driveshaft if I want the 12mm bolts?

Would it even matter if I am swapping to a Driveshaft Shop driveshaft that eliminates the couplers?

 

Building a racer? No, you are just replacing the shaft. According to the manufacturer's page, you have to mod the factory parts to accept the 12mm bolts.

 

They sell a solid aluminum that works with the 10mm bolts. I don't mind modifying my torque tube if the 12mm upgrade is that important, though.

 

I mean.....if you are going over-the-top with the driveshaft, you might as well do the 12mm bolts, right?

 

Finding a 12mm torque tube for sale near me is difficult and I imagine shipping would be insane.

I've read that you can drill the 10mm holes to fit the 12mm, but wouldn't that weaken it?

 

I recall reading that the 12 mm couplers are a different thickness than the 10 mm couplers — I do not recall which was which. Anyone who makes custom center shafts must already know what is needed — if they don’t then they are not really the shop to go to.

 

I’ll call Tick on Monday to get more details on that. I wasn’t aware of a thickness difference.

Thank you for letting me know!

 

Curiosity gets the better of me at times. While finding any specs listed for the GM couplers is more than difficult, finding the data for the equivalent BMW couplers is not, and the specs coincide with how things seem to work in the real world, so I'm thinking they are correct. From that data, the 12mm couplers are 4mm thicker, so the center shaft would need to be 8mm, or .315" shorter to work in the same outer tube. I'm sure there is some amount of play in there between front and rear bearings, but I doubt it's remotely 8mm.
10mm coupler:
O/D: 110mm I/D: 40mm Bolt Circle: 78mm Thickness: 38mm
12mm coupler:
O/D: 110mm I/D 38mm Bolt Circle: 78mm Thickness: 42mm

 

TDP sells a fresh front shaft fyi: https://www.txdrivetrain.com/product...r-input-shaft/

The real question is whether you intend to retain couplers in your design or not. Because the whole 10 vs 12 thing only relates to the end adapters and the couplers. I'd design it to be 12 given the power you will see and given that I sheered a set of 10mm bolts when NA on a stock LS1 with headers when giving it the beans.

My guiding concept when deciding on the couplerless aluminum driveshaft was that the car is going to make enough power to break the stock parts. A carbon fiber shaft is held on by glue and can pop and turn into spaghetti. Not an option. Couplers themselves and the bolts, while they CAN handle a lot, can still let go. So I went couplerless, loc-tited the bolts, and then put a small single mig bead on the "bottom" of each bolt where the thread sticks out next to the adapter face because I never want to have to service the torque tube unless it fully lets go. The shaft is solid. The bearings are SKF. The bolts will never back out. There are no couplers to explode. Caveat: some say this will add to NVH when driving. Counter argument: the guys who say that are NOT the ones frustrated by having to tear the car apart again as a DIYer like myself, and so unless it is utterly unbearable I will enjoy keeping this setup.

I will say, having recently bought a 12mm tube for my now-dead daily driver coupe that even when picking through a pile of potential tubes (there were perhaps18 C5 and C6 tubes, of which 5 were 01-04 12mm) most were junk. Some would not rotate. Some had the nose on the clutch end destroyed and worn around. I chose the pick of the litter and later re-sold it after the wreck.

 

Vettepros in Charlotte may have what you need. Used them a few times with good results.

 

Thank you!!

If I stay with 10mm, I would run the DSS 3" Aluminum Driveshaft (Torque Tube) 10mm bolts.

Thanks! I'll check them out!

 

Visual walkthrough on FB in the "corvette drift community" page:



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