rustyguns

Hey guys need to do some drive train work. RnR clutch etc. while I am there want to do the drive shaft rubber u joints and replace the bolts

ARP make anything for the old 10mm bolts or should i get a specific high grade bolts?

or....drill and tap and put in 12mm and larger rubber u joints?

what you guys think... FYI I am not rich

ipuig

The strength of the OEM fasteners is more than adequate. I do not believe you will gain much stength and reliability with the modifications you are considering, you may even reduce it.
The best solution in my opinion would be replace your existing drive line with a complete used 2001 & up torque tube and propeller shaft assembly.

chevylad

I never heard of anybody breaking bolts, only propshafts twisting or couplers falling apart.

I have seen two different style poly couplings. One from the Driveshaft shop and one from Prothane (I think).

The Driveshaft Shop one is a big round poly donut with metal sleeves and the Prothane one is an aluminum donut with poly bushings inserted into the aluminum with sleeves on the inside.

Neither is exactly cheap, but the Driveshaft one I have seen in numerous car build ups in magazines including several big horspower cars (1000 hp). The Prothane one is unproven in my mind. It may be just as strong. I haven't heard of anybody using that one so I can't really say.

I have both sitting on a shelf somewhere. I'll post a pic later.

MawneeC5

^ I've sheered the front coupler 10mm bolts right off. But I was running 650RW+ and shifting HARD. And mind you this was after years of hard driving and abuse.

Unless you are running huge power and tracking a great deal the stock 10mm parts should work just fine. Throw in some new couplers and call it a day.

chevylad

Two styles of polyurethane couplers and neither is exactly cheap:

http://forums.corvetteforum.com/album.php?albumid=18158

rustyguns

good to know! thanks!

we did have one guy sheer the 10mm bolts with about 450 rwhp
but they were stressed from a previous failed donut

rustyguns

Thanks i plan too eventually ,just can't afford it right now

1stGlance

Got a 2003 TT for sale - but it would probably need new bearings and couplers - willing to let it go for 250.00 & shipping.

helga203

When i did mine i went to hardware store and bought 8 grade bolts for $3 700rwh with toyo 305's no problems here. FYI
P.S. 10mm

rustyguns

do you road track or autocross?


I was thinking about that... I am guessing the stock bolts are not Grade 8?

Also I was considering high grade aviation bolts because they have very high sheer strength. do not where to find them though

LoneStarFRC

The difference in the two versions is more than just a different diameter bolt being used in the couplers. The later model torque tube assemblies have a larger diameter driveshaft as well.

rustyguns

very true, but I have never seen a 10mm driveshaft failure on a stock engine, have you ?

LoneStarFRC

Not to my knowledge, but then again it was GM that made the change to "stock" C5s, not me. When the Z06 was introduced on '01 is when it (change) occurred. The horsepowers went from 345 or 350 (regular C5s) to 385 (first year of the Z06). It (Z06) increased to 405 on '02.

Hardly a huge increase. Maybe their engineers just wanted to make the drive shaft/torque-tube stronger for no good reason. Perhaps they should have just let well enough alone since there were no failures being experienced on the "10mm" driveshafts to the best of my knowledge.

I guess I mistakenly thought you were going to be modifying your power levels, or at least had intentions of doing so in the future. If you are not, then just get the stock GM 10mm couplers and not spend extra on drilling out bolt holes and re-threading, etc when it's something not needed on a stock setup.

blown81bu

I think arp makes a 10mm bolts in 5 packs
Does anyone know the dimensions and tread of the stock 10mm bolts

I wanna order some for my set up

lionelhutz

The 12mm couplers are thicker. You can't just replace 10mm ones with them.

blown81bu

it sucks i have a 10mm driveshaft..either i keep the 10mm or just find a 12mm set up
I have 8 sec power w 275pros

lionelhutz

You could get the Driveshaft Shop to fabricate a shaft with the right length and 12mm bolt ends and then drill and tap your shaft ends for the larger bolts.