1 piece driveshaft conversion

[toddtheodd]

Ok, so I know I can replace my 2 piece driveshaft for a one piece driveshaft in my long bed truck. (This would definitely fix my u-joints / carrier bearing problem)
What I need to know is what kind of conversions I need to do to get it to work.
Like how long does the driveshaft need to be? I know that I have the short nose turbo 350 transmission (I've checked into this before when checking into a 700r4 conversion).
Also, do I need to remove or cut the crossmember that the carrier bearing is in the middle of?

Basically, what kind of problems am I going to run into, and how do I get around them?

Todd

[Super Duck]

Take a mesurment from the back of the trans to the inside cup on the pinion. that will give you your overall lenth. subtract 2" for slip and that should take care of the shaft then if stuff will get in the way, remove it.

[sweet n rare67]

If anyone has done this conversion please respond, i am also very interested in this.

[toddtheodd]

I'm worried that if I remove that crossmember it will cause problems.

[Super Duck]

you shouldn't have to rem the crosmember just the hanger for the carior bearing. at worst notch and plate it

[jlmtrout]

This is an easy conversion. I had mine made at Truck Pro (they work on 18 wheelers) for about $185.00 including solid u-joints. Only thing I had to do was take a sawzall and cut the bottom of the carrier bearing crossmember for clearance. Good luck and keep on truckin'.......Jerry

[68C15]

I would stay with the 2 piece. there is nothing wrong with this system. in my opinion it works better due to shorter shafts are less likely to be out of balance & no mods are needed.
Todd

[toddtheodd]

jlmtrout, do you remember how long the driveshaft had to be? This is my daily driver so I can't have down time on it.

[Longhorn Man]

Todd...it'll be over 6 foot long, so you need to call your driveline shops and see if they will even consider doing it.
Most will not.

Nothing wrong with the 2 pc, I've seen a daily driver that was doing 12's on the weekends running a 2 pc.
Never a problem.


if yours keeps falling apart, there is something else wrong.

[toddtheodd]

I believe that somebody said before that Texas Gear and Axle here in Fort Worth would do it.

[Tx Firefighter]

Nope, it's Ft Worth Gear and Axle.

Call them or go in. They'll tell you exactly how they want it measuerd so they can build it right.

I use them for all of my driveshaft work. Top notch operation. Less than 10 miles from your house too.

[gregfull]

I had mine done by CT Driveshaft here in Houston. I called them, they told me where to measure from, I took them the old driveshaft so they could take the yokes off of it, and in about two hours I had a new one piece. By the way, it was on a 72 ssuburban. Call a local driveshaft shop, they should be able to help.

Good luck.

[toddtheodd]

Tx Firefighter, do you remember how the prices run at Ft Worth Gear and Axle?

[Tx Firefighter]

I paid 200 for a whole new driveshaft with a new yoke and u-joints included.

The yoke was 60 of that price.

[toddtheodd]

And I guess I'm definitely going to have to cut the crossmember. I didn't think that sawzall was going to get as much work as it has when I bought it almost 2 years ago.

[1970 CST Short Wide]

I just did this on my sons truck a Lowered long bed. I taked to my local driveline shop 1st, They told me where to measure. Turned out to be 71 and 3/4 inch . We removed the center support bracket and it fit perfect. No vibrations or shakes at all. New yoke included ran $275. Thing are more $$$$ here in Ca . It does work, Good luck

[bigskiohio]

If the length is a problem why did gm put one piece on later long beds .I have one from 1980 gmc and I haven't checked for fit but it looks longer then the two piece.

[bigdog69]

Another way to fix your "u-joints/carrier bearing problems" is to use a two piece shaft with a slip joint on the rear shaft. This system is used on late model trucks and is a lot better, no long shaft to worry about.

Gene "Big Dog"

[Tx Firefighter]

Your 80 model would have had the 9 inch tailshaft transmission.

I've always suspected that's why they went from 6 to 9 inch tailshaft transmissions in the next series of trucks, so they could run 1 piece shafts in long beds.

Like I said, I suspect that's why, I have no proof of it though.

[toddtheodd]

which brings up another question.
What are the pro's and con's of a 1 piece driveshaft?

[Tx Firefighter]

As long as it's built properly, there are no cons to a 1 piece driveshaft.

Back in the day, they had trouble making a driveshaft long enough that wouldn't whip under high speeds. Now, if needed, they can even make them out of exotic stuff sometimes like fiberglass or other composities.

A good driveshaft shop (like FW Gear and Axle that I recomended) will have no problems making you a nice steel 1 piece shaft that will run true and smooth. They also use Spicer u-joints, which in my opinion are top notch.

There are plenty of downsides to a multi-piece driveshaft. That carrier bearing and extra u-joint mainly.

[robertwb]

my dad put a one piece in a LWB back in the late 80's -it was a ford drive shaft he found that was long enough and he just got the special u-joints to adapt ford/chevy parts and it worked fine

He did have to cut the lower part out of the x-member since he didn't want to lower the truck though

[kbs71]

I just put this in another thread. I got a 4" aluminum driveshaft from the junkyard last weekend. They also had a carbon fiber one there. I paid $50.00 for it. It was 5/8" shorter than the 2 piece. The aluminum one was off a 98 1500 and the carbon fiber one was off a 2002 Yukon. The only thing I had to do was put odd ball u-joints (3 1/4" X 3 3/4") that I got from a driveshaft shop. They cost about $30.00. I trimmed the opening of the crossmember 1" all the way around and welded a strap on the bottom for support. I'm having a tubular hoop made and welded in next month, which will eliminate any clearance problems. Luckly I know some racers who have all the stuff to do that for me.