Tod74

This probably is a silly question but here goes.

What is a good driveshaft? ops: What I mean is...what do I ask for / look for when shopping for a drive shaft? I have never used anything but a stock drive shaft and U-joints,and have never had a problem.. but I've never had a car that left as hard as this one does either. What is the difference in the universal joints ? Are they solid or what? Just made from better material? The car weighs just over 3000 lbs and the 60 ft times are low 1.30's with a best of 1.32.

540/ glide with brake.

So I guess the actual question I am asking is..If I go to have a drive shaft made for this car..what do I ask for?

Thanks in advance for helping out a green horn.

jmarksdragster

The idea is to use as reasonably large a diameter as possible. Racing u-joints are solid, no grease fittings. I'm not sure who makes good ones anymore (dragster), Lakewood used to and Dana/Spicer also.

qtrmile2

We use chrome moly driveshafts with 1350 ujoints. Not sure who you would have where you live but we use Jerry Bickel Racecars to make ours.
His shop is about 4 miles from where we live. If you need his number let me know. It might be overkill for your application but I do know stock will not work for very long.

signsbyesa

just beefed up mine with strange pinion yoke for 1350 joints along
with the trans yoke both from strange and went with a balanced
inland shaft, real nice people
http://www.iedls.com/

OneBadGMC

Call and talk to the gurus at Mark Williams.

http://www.markwilliams.com/drivesha...CategoryID=126

Driveshafts are manufactured based on torque/hp requirements, as well as vehicle weight and finish line RPM.

All driveshafts have harmonic distortion in them. The key to getting one that will live long term is to either have it avoid the RPM range (driveshaft RPM, not crank) that the distortion occurs, or get it through the distortion rpm range very quickly.

Mark Williams is one of only a FEW (read 3-4) in the country that can dynamically balance a driveshaft with their driveshaft dyno.

http://www.markwilliams.com/torsion.aspx

After having gone through a couple driveshafts (one mild steel, and another a larger diameter moly), I got sick of spending money and still continuing to have failures.

I spent more than I wanted to, but to play you gotta pay. I wound up with a single carbon fiber driveshaft from Mark Williams, that they stated they had used with success in Pro Mods and Pro Stock. Also went with their billet T-400 output shaft, and billet Dana 60 input shaft.

I've yet to have this driveshaft fail... And we're launching against a brake, with boost in a 3450 lb truck.

Tod74

Thanks for the replies guys.

bjuice

Todd- the moly shaft is a win-win everytime...on my cars like the 67 camaro..i have custom mild steel drive shafts made 3.5 inches in diameter and 0.83 wall thickness and have had zero problems so far..

regardless i use Billet steel slip yokes..the drive shaft problems i have seen with my own eye's is the 1350 u joints and slip yoke breaking causing the drive shaft to fail....

Billet slip yoke all the way...cost is about $200.00 but well worth it..

Brian

Tod74

3.5 x .083" wall thanks. That was what I wanted to know.

signsbyesa

if nothing changed on your car, like longer trans, and need to
order a shorter or longer drive shaft, make sure that your
car is fully loaded even with a full tank of gas to make sure
the structure is under the full wieght of the car to get an
exact measurement for your driveshaft, you can order the "molly"
and because you did not measure it under full wieght, that
"molly" will be for not. if you contact a good dealer, they
will guide you and tell you what you need, and all performance
after mkt shafts are thicker then OEM, good luck with "molly" :wink:

Tod74

I learned that one the hard way when I was in high school. Thought I had the correct length driveshaft it was actually too long. ended up ruining a trans case and a thrust bearing. One of the many stupid things I did back when I knew everything...you know.the teenaged years when we are all experts and the adults know nothing. :wink: