Some of you might know, my driveshaft is hitting the bottom of my crossmember. I have the big aluminum drive shaft that is something like 8-10 inches in diameter. This is partly due to the fact that I swapped out the 60e for an 80e, figuring it messed with the angle's and allignments of the drive shaft. So I went to a local shop that only does driveshafts that was recommended by some people on here and they looked at my set-up and told me they couldn't help me out.
So my question is, has anyone gone from a one-peice aluminum drive shaft to a two-piece solid steel one? The underside of my truck is full of turbo, custom exhaust, Fuel pumps and train horns so there isn't much room to begin with and if somthing break's there's gonna be alot of damage.
They said they would make something up for me but not guarantee it at all and suggest I stay with the aluminum one.
Advice?

 

If you have the Cash get one from someplace like Dynotech or Dennys and then put some loops on that bitch

 

You probably won't get a one piece steel made for that length. I tried and only found one shop that would actually consider it, and when they asked my hp/tq they laughed and said go with a beefy two piece. Where did you get you Al. one?

The reason the aluminum one can be that long is due to the diameter. The Al. can be a larger diameter and thicker than steel due to the weight/harmonics. A larger dia. tube won't flex as much as a smaller dia. with the same length.

Think of it like this: Take a dowel that's 3ft and push on the ends. Now take a 1ft dowel and do the same. Which one will flex more? Increase the diameter of the 3ft'er and you might be OK.

As for your local shop not being able to do anything for you, that's bullshit. My truck is an EC, but the same wheel base and I have a TH400 which is shorter that your 80E. What you need to do is get a decent used 2 piece out of a 2wd EC with a carrier bearing and have them modify it for you length and power.

I have 1350 u-joints and .080 wall tubing I believe. The good thing about a 2 piece is that the diameter of the tubing can be smaller so mines only like 2.75" or something. The bad thing, is that tubing is expenssive becuase its an odd size. The factory carrier bearing and yoke is actually fairly robust, even when compared to aftermarket ones so I kept it. The more metal the better and aftermarket ones have a lot of rubber/polyurethane. Your truck should have the carrier bearing crossmember under there too.

 

Oh yeah at your power levels and weight, and if you hook up at the track, I forsee any aluminum shaft getting fatigued.

 

You might want to invest in a drive shaft safety loop, Just my .02......

 

Is your pinion angle and such fine? If so, what about getting the crossmember sectioned to clear the driveshaft?

 

You could have a nice safety loop installed while modifying your crossmember. It might not be in the exact perfect place (6-8 inches from the front universal joint), but it's better than none.

 

First off thanks for the feedback guys.
The Aluminum drive shaft came stock with the truck, 05 model year. They are rated for 105 mph and like vanilla said the size of it enables it to be so long, another reason for it's diameter is it can handle more torque.
When I spoke with the guy at the drive shaft shop he said a one piece steel drive shaft would twist and break in a heart beat should I make one that long. Especially with the torque I'm putting to it.

I have no problem spending big bucks on this because if I cut a corner here I'll lose my rear-end, tranny, turbo, fuel pump, train horns and possibly damage the engine.



I don't know about what my pinion angle is and when I was under the truck with the driveshaft guy he didn't think the angle looked off but this is what the crossmemeber looks like so somethings up!!





What I learned is the ideal ratio for a two-piece drive shaft is 40/60. Front end of the shaft is 40% and the back half is the other 60%. Nearest crossmember where I can put the carrier bearing is back by the rear end which would make my split 80/20 which is actually dangerous. Nearest crossmember forward would be even worse putting the ratio at 10/90. So I have to fab up a crossmember which wouldn't ordinarily be a huge ordeal except I have the STS on one side and my fuel pump on the other side running front to back.

Bro that's what I though too but apparently my frame is different. I'd have to look at a buddies truck to see what his frame looks like to see how different ours are.

 

What do you guys know about Carbon fiber driveshafts?
If I can do a two piece I think that would be ideal...rip one out of on old chevy, test it and speed calibrate it, mount a crossmember and beef it all up and voila.
If I can't go that route what else is out there?

 

What crossmember did you use for the 80e swap? Did it maybe raise up the tailshaft too high?