2nd Gen Non-Engine/Transmission One pieace driveshaft

[jabird]

Does anyone know for sure what the max. length you can take a driveshaft to? I have been thinking about changing to a one piece driveshaft for sometime now, but I've gone to three shops now and been told by all of them that I don't want to go over 65". Now just roughly I think a quad cab long box is around 76". I know I've read a few post of guys having one piece shafts made. So whats the deal. What dia. tubing did you use? What was the wall thickness? What size u-joints did you use?

 

[BigPapa]

Bird,



I was told by a very good drive line shop to stay with what I have. That's what I did.



I'm sure if you go in there with cash and tell them to make you one that is 76" long they'll do it but looks to me that if three different people that make their living building drive shafts tells you not to you'd listen



Scott

 

[ob1kobi]

Get ahold of RacinDuallie, he converted to a one piece drive shaft and can probably answer all your questions.

 

[RacinDuallie]

jabird- I believe I spoke to you about the 1pc. driveshaft for the rear? If you go to the thread: Hate seeing RUST. . on this same forum you can see the driveshaft in one of the pics-4th one I think... . I'll try and measure it tonight when I get home..... Solved my vibration probs and eliminated that stupid spitshaft bearing arrangement... .....

 

[RacinDuallie]

o. k. mine is 71" measured from weld bead to weld bead- and is 4" dia. - the thickness?

 

[jabird]

Racin... . after you and I p. m'd each other thats when I got to checking around with shops in my area. Haveing no luck what so ever with any of them. I know what your saying also BigPapa... ... three different places say the same thing then maybe stay away. I was just trying to think alittle outside of the box here. Alot of the trouble I'm haveing also around here with any shop is they are under the impression that is impossible to make over 400hp with a Dodge. I know with my set-up as it stands I dont have that much power, but... ... ... . hopefully things are going to be changeing soon. Plus the vibs are driveing me nuts. I've already been through my driveline several times. I dont feel that it could be balanced any better, so I would like to try a different route.

 

[Partyat33]

From what I understand a one piece has more vibration and thats the whole reason it is a two piece. I will shoot you a pm tomorrow with the local guy here who does big truck drive shafts. He redid mine for the Auto swap.

 

[RacinDuallie]

From what I understand a one piece has more vibration and thats the whole reason it is a two piece.

Funny thing is though, I tried EVERYTHING possible to solve my vibrations with the stock 2pc. set-up- nothing solved it. Finally got so fed up in dealing with it I took my truck to the ONLY shop I trust and demanded that the weak link be taken out- put in a beefy 1pc. and dynamically balance it!! When the 1pc. was done and installed-all my previous problems with driveline vibrations and driveline harmonics were gone- and have been gone since.

 

[Dane]

A one piece vibrates less.

From what I understand a one piece has more vibration and thats the whole reason it is a two piece

Nope, it's the opposite. A one piece will vibrate less, much less.



The reason for the two piece is driveline angle.

 

[Partyat33]

Shows you what I know.



Jeff, try Dupre Inc. I think John is the driveshaft guy. 815-744-7800. They are a heavy duty truck supplier.

 

[RustyJC]

All else being equal, the longer the driveshaft, the lower the lateral and torsional vibration critical (resonant) frequencies will be. Lateral vibration is the tendency for the driveshaft to whip or bow. Torsional vibration is the tendency for the driveshaft to wind up and unwind along its length. By lowering these critical frequencies, there's every chance that they can be brought down into the operating range of the driveshaft.



To raise the lateral and torsional vibration critical speeds, the one piece driveshaft must be stiffened by increasing the diameter and/or the wall thickness or by using a stiffer material. Then weight becomes a consideration. If it were me, I'd want the driveshaft shop to have a qualified engineer who can run a lateral and torsional vibration analysis on the new one-piece driveshaft before fabricating it.



JMHO... .



Rusty