LWB driveshaft suggestions.

[shawn57nomad]

Hey guys and gals, Just wondering if anyone has a one piece drive shaft in their lwb 2wd truck. I would like to know if new is better or junkyard units rebuilt are okay too. If Junkyard shafts are okay what years of GM 2wd truck can I get one out of. I have sbc with a turbo 400 with a bolt on yoke if that helps any. All post would be greatly appreciated.

[Andy4639]

I was told it want work well. I just had my spare two peice done. For what it's worth.

[Bob 68327]

As far as I know gm never made a 1 piece shaft in a 2wd with a slip yoke built in it. You might measure some 4wd and see if they are long enough or change the tailshaft on your tranny and get a slip yoke . My 2cents , Bob

[69chevytruckin]

My friend has a 72 GMC with a one-piece. However when my dad called a good driveshaft shop in my area the master mechanic said it would not work to much lope.

[Andy4639]

You would have to redo the support where the center bearing rides now. With the angle it would have to be cut from what I have been told.

[shawn57nomad]

Cool guys thanks 2 piece it is...KNock knock BOB need drive shaft setup i,m thinking when u get a chance. Thanks again.
How does the setup measure with a bolt on yoke?

[brad_man_72]

at that lenth the diameter of tubing that would need to be used to not fail at a high speed creates clearance issues. save alot of time and trouble by sticking to a 2 piece.

[Bob 68327]

Mine has been over 90mph and it fits in through the hole where the carrier bearing used to be . I had it made a driveshaft shop and it wasn't cheap . I'm glad everyone here say's it won't work . It makes me feel better that I made it work with no troubles . The biggest problem I see with Shawn's is the bolt on yoke . With that he needs to go back to the 2 piece set up . Bob

[PHAT TONY]

Machine shop here said they will make a shaft up to 78" long, that's 9 longer than needed.

[shawn57nomad]

Just measured the one pc in the garage and it is about 71" from joint to joint. the Diameter is about 3.5" is this going to be good enough for a shop to use for a one piece? Thanks guys.

[adpostel]

I'm running a 454 BBC with a TH400 Trans and have a one piece that was built at a local DS shop. It has the heavy duty greaseable U-joints and was fairly cheap to do. The measurement they will need is from the face of the output shaft on the trans to the flat portion of the yoke on the rear end, so that would be the first flat piece of steel you get to on the rear end yoke (just for clarification) Mine was 70.5 inches. The original bracket where the carrier bearing was will create issues fitting the one piece in. After hours of banging my head trying to get it to work, I finally took out the sawzall and just cut the bracket off. It went in like a glove after that. I don't know what the fuss is about, think about all the suburbans and trucks that had one piece shafts, why would the manufactuer put them in if they were unreliable. I'll take some pics of mine and post them up later today or tomorrow.

[adpostel]

Shawn, I don't think your one piece will work, go get the measurement that I just posted, that will give us a better idea. And I can tell you this, I had a th350 in mine before the 400 and i had to get one re-made, so i have a one piece for a lwb with a th350 trans in the garage.

[Bob 68327]

Pics of mine as promised . After I took these I felt a little embarassed that I still need to cut the trailing arm mounts off Here ya go . Bob

[Longhorn Man]

there are many many variables
One that bob's points out, is ride height. His shoots straight to the rear, not much suspention travel. I don't think anyone needs to explain what would happen if his rear axle were another 4 to 6 inches lower, and then was unloaded like going over rail road tracks.
Rear suspention type is another important one. Looking at bob's again, with a pipe of that diameter, if he had a coil spring rear, which moves side to side, the shaft can and would probably tag the cross member.
Drive shaft shop. Many who will build one over 60 inches, SHOULDN'T
As far as the measurement directions go... call your driveshaft place, the directions above are NOT the industry standard.
Expect to spend quite a bit of money to get one done properly... esp if you need a slip shaft in the one piece shaft.

[jrdz2120]

I have gone to driveshaft king and stan owen co. out here in dallas, and both recommended I go to a one piece on my longbed since it has a 4/6 drop. 200 bucks using the same slipyolk. I gave my two piece one more try and no problems yet. The tubes were all out of balance and I had the carrier bearing welded around the edge and so far so good.