Driveshaft Material: Aluminum or steel?

StreetSnake · #1 (**permalink**) 12-30-2009, 06:48 PM

Just wondeing the advantages/disadvantages of both types of driveshafts where. also what is the benefit of balancing the shaft.

ratsnst1 · #2 (**permalink**) 12-30-2009, 06:58 PM

Quote:

Originally Posted by StreetSnake

Just wondeing the advantages/disadvantages of both types of driveshafts where. also what is the benefit of balancing the shaft.

chrome oly.

Silverback51 · #3 (**permalink**) 12-30-2009, 07:18 PM

The advantage to an aluminum drive shaft is weight. But when you look at the length of our drive shafts, it's not worth the effort.

If you do not balance the drive shaft you will have a terrible vibration. Have it balanced.

StreetSnake · #4 (**permalink**) 12-30-2009, 07:27 PM

Funny Story: stupid on my part. After finishing the completion of my cobra, if you really ever can

, I took the car to the tuner to set up the 427 TWM injection. didn't bother doing a run through of the rear suspension. Tuning went great, drove it home but get hearing a clanging noise when i hit bumps. you guessed it, the drive shaft was hitting one of my chrome oly driveshaft loops. I ended up really doing a number to both, but after setting the pinion angle I was good to go. I never noticed any vibration or anything odd from my stupid oversight but was thinking about fixing/replacing the driveshaft and chrome oly loop.

Your guys recommendation. Keep the same driveshaft and have it balanced, get an new one (what material) and have it balanced.

mickmate · #5 (**permalink**) 12-30-2009, 07:33 PM

I would fix your steel one. If you look at the aluminum ones they are much bigger diameter to get the torsional strength. If you have a bigger driveshaft it has less clearance now from a softer material.

Woodz428 · #6 (**permalink**) 12-30-2009, 07:33 PM

chrome moly??

StreetSnake · #7 (**permalink**) 12-30-2009, 07:36 PM

Sorry I understand it as chro-moly. I'm sure someone on here can give us the correct spelling and what it actually is. Me, not so much.

mickmate · #8 (**permalink**) 12-30-2009, 07:44 PM

Yep you got it Chromoly from Chrome Moly 4130 it's strong enough alright we've used it for rollcage tubing. When the tech had to drill a hole in it to check wall thickness he couldn't drill it. Eventually got a hole thru it and made us take it out for being too thin. Strong though.

StreetSnake · #9 (**permalink**) 12-30-2009, 07:50 PM

Another topic. Do you think there is anyway we can figure something out for you to build my a gas tank or would it be to difficult to make sure it fits and hooks up?

ratsnst1 · #10 (**permalink**) 12-30-2009, 07:52 PM

Quote:

Originally Posted by mickmate

Yep you got it Chromoly from Chrome Moly 4130 it's strong enough alright we've used it for rollcage tubing. When the tech had to drill a hole in it to check wall thickness he couldn't drill it. Eventually got a hole thru it and made us take it out for being too thin. Strong though.

I hear its the best , for stuff like that my a arms are of the same stuff, and my drive line.

Rick Parker · #11 (**permalink**) 12-30-2009, 09:00 PM

It is my understanding that the welds have to be normalized by controlled heating to prevent them from being brittle. The alloying of steel and chome (not Chrome plating) increases the strength allowing for thinner materials or wall thicknesses allowing for less weight & the same strength. All dimensions being equal there is no weight savings but immense increases in rigidity. I heve seen .035 wall material x 3" OD used in exhaust systems.

mdross1 · #12 (**permalink**) 12-31-2009, 03:09 AM

Have a specialized shop make the shaft no worries!

RICK LAKE · #13 (**permalink**) 12-31-2009, 03:16 AM

StreetSnake For what you save in weight is not worth the safety in time. ERA has a steel shaft and in 12 years no problem with 95% racing. I have seen aluminum ones shatter. GM only uses them on some truck where they can have a 5-6" diameter shaft fit. The most important thing is, have the correct angles between the trans and the rearend. You need this to off set each other to remove vibration in the drive train line. I think NASCAR uses them and then throughs them out after a couple of races. I think welding steel to steel is a stronger connection than tig welding aluminum to aluminum. If you have room, have 2 drive shaft loops installed in the car for added safety. Have a 1" clearance from top to shaft and 1" side to side. ERA has used steel shafts for over 30 years. I think if the aluminum was 100% safe they would switch or give a choice. Rick L

PANAVIA · #14 (**permalink**) 12-31-2009, 03:25 AM

Even in performance mustangs with a longer shaft we usually go steel.

The added cost and logistical complexity that aluminum costs you is just not worth it.

mickmate, and Silverback are both on the right pathway here.

vector1 · #15 (**permalink**) 12-31-2009, 05:10 AM

had a driveshaft made for something similiar, caterham 7, and the difference between aluminum and steel were real small, less then a pound.

xracerbob · #16 (**permalink**) 12-31-2009, 07:02 AM

I looked into having an aluminum shaft made by a guy who does them all the time. He advised against it since the shaft was so short and the benefit is negligible. Also, he has tried to do them and often they can not be balanced. He said he would try to make one if I really wanted, but no guarantees on it being usable due to the balance issue.

I got my steel shaft here:
http://www.dennysdriveshaft.com/c6_c...iveshafts.html

He knows what he's doing and does a beautiful job.

StreetSnake · #17 (**permalink**) 12-31-2009, 12:41 PM

I just crawled out from underneath it. The shaft is all scuffed up and I pulled the chromoly loop to refinish. So, i didn't take any measurements but the shaft looks to be a 2". Because the shaft is so short (less potential for vibration) would you still recommended either having a new one put in or fixing the one I have.

Ant · #18 (**permalink**) 12-31-2009, 01:05 PM

I had a driveshaft shop build my driveshaft with Chrome moly weld on ends in 3" diameter x 0.83 wall steel tube also using 1350 u/js, with my Jerico I had to go with a special hardened front transmission yoke. All very strong etc for my high hp engine.
I asked the driveshaft shop about going chrome moly tube, and he didnt recommend it and said steel driveshaft tube welds better to chrome-moly ends with correct welding rods, and they made a top quality job. The other bonus from dealing with a proper recognised shop is its a compliance requirement for certification for the road.

A friend got a driveshaft done locally and they ground some of the weld off to ends to balance it, I was horrified at the standard of work so went to the driveshaft shop in the big smoke. This chap welded proper little tag weights on, and charged me $239NZ but I supplied all the parts apart from the tube!

bandito · #19 (**permalink**) 01-02-2010, 03:13 PM

So...if you want one strong and lightweight, and not have to worry about the dreadful "pole-vault" go with one of these:
http://www.pstds.com/

Can't beat a CF driveshaft!

RICK LAKE · #20 (**permalink**) 01-03-2010, 06:11 AM

bandito While carbon fiber is very strong it is BONDED to the ends. The e-town guys have tryed these and lost cars from the ends twisting apart. Kid behind my house has and 02 firebird for racing and got an carbon fiber for like $600.00 and the end twisted where its bonded after 30 runs. This is a 10.9 car. Again for a street car with 400hp or less no problems I have heard of. Serious racers are all running steel or aluminum. Rick L.