Rear drive shaft selection

[PCFRover]

I am installing a 3" lift on my 95 D1 and am looking for advice on which drive shaft to use for the rear. I have a DC TW that is going on the front but the rear is currently the stock RotoFlex and that has got to go. I have to buy something so should I get a std U-Joint shaft, or go with a DC one from Tow Woods or GBR?

Gary

 

[Rover3]

A standard ujoint shaft will do, but a TW or GB DC shaft might be more sturdy and vibe free. A standard ujoint might still vibrate. I also just bought a used TW DC rear shaft that I have yet to install!

 

[Mike_Rupp]

A conventional ujoint driveshaft and a DC driveshaft aren't interchangeable. With a ujoint shaft the pinion and transfer case output shaft must be parallel. With a dc shaft, the pinion must be pointed directly at the transfer case.

 

[LostInBoston]

A conventional ujoint driveshaft and a DC driveshaft aren't interchangeable. With a ujoint shaft the pinion and transfer case output shaft must be parallel. With a dc shaft, the pinion must be pointed directly at the transfer case.

I thought with a u joint, the pinion should be pointed at the t-case. but the DC could be parallel?

anyways, i would go with a GBR rear, DC or ujoint, theyll both work great. if going 3" and up, get the DC. I have a double DC TW on the front, but not needed on the rear.

 

[Mike_Rupp]

Let me be more clear: on a driveshaft with a ujoint at both ends, the pinion and t-case shaft must be parallel. On a driveshaft with a double cardan joint on one end and a ujoint on the other the dc end must be at the t-case and ujoint must be at the pinion. The pinion must be pointed directly at the t-case. The problem with the dc shaft is that the pinion must be rotated up quite a bit to achieve this angle. The lower spring perches will be angled back which cant be good for the springs and the pinion bearing will be much higher than before and get less contact with the diff oil.

My brother has about a 4" lift with no problems with just a conventional ujoint driveshaft.

 

[marc olivares]

i also run a 4" lift w/ a stock D1 u-jointed rear shaft.
adjustable rear links are a must though to flatten the pinion angle at that lift.

mike is right D/C is not necessary on a disco rear, and tend to cause more issues then they resolve.

 

[PCFRover]

Thanks for the info. It sounds like a standard UJointed shaft is the way to go. So what years have can be fitted here, 97 and up or are DII's different?

About the front now, with the 3" spring lift will the front pinion end up pointed at the Tcase or will there be an adjustment needed to make this happen in order to use a DC shaft?

 

[PHARAOHDISCO]

I have a 3" lift on my 96 D1. Went first with a standard LR U-jointed driveshaft and still had some vibes and I had installed Rovertym heavy duty and extended rear links to correct pinion angle. Changed it to a Tom Woods double cardan driveshaft and it was perfect.

 

[antichrist]

FWIW I put a GB double cardan on the rear (turns out I had to get it balanced, at a cost of $30) and recently put a DII double cardan on the front. This is on a '95.
Soon as I get around to pulling apart my spare DII front propshaft (so I can get measurements) I'll get greasable u-joints for it and the one I installed.

 

[PCFRover]

Now I am confused again. With all these conflicting opinions it seems that no matter what I end up getting, it might be wrong.

I am going to start a new thread on Drive Line geometry....

 

[Sergei]

Well to truly compensate for lift you need to correct angles and stuff. Just driveshafts wont cut it.

You need corrected front radius arms, rear links to sort out pinion angles..
You may need to correct A-frame joint mount and length of swaybars (if you got those) to help with it..

& etc..

However in simple words - just get GBR or TW or ye stock u-jointed shaft and be done Heck you can even keep your current
rotoflex, but you got to check it more often to been in pristine condition.

 

[Eric N.]

http://www.sixstates.com/modules.php?name=Content&pa=showpage&pid=32

this might help you

 

[PCFRover]

I was just trying to avoid the trial and error metod, but that seems to be the way it is with these rigs. I will get a DC rear shaft and we'll see what happens!

Now all I need to do is decide on TW or GBR!

Thanks for the input.

 

[gummikuh]

Hi

I have a 3" lift and am running a standard double u joint rear shaft and it is perfect, it has plenty of room to drop, the rotoflex is rubbish as the centre peg restricts its movement, and will not have enough flex to put the flanges on the same plane.

If you get part number STC4858 you will not need the spacer ring.

I got my rear shaft for ?10, the flange was a bit more at ?60, but they do give you a new bolt and oil seal.

I have scorpion racing trailing arms and these have spacers in to put the axle back into it's right place.

I try and keep it as stock as possible as parts are so much cheaper and easier to get hold of.

Best of luck

Pete

 

[LostInBoston]

I was just trying to avoid the trial and error metod, but that seems to be the way it is with these rigs. I will get a DC rear shaft and we'll see what happens!

Now all I need to do is decide on TW or GBR!

Thanks for the input.

Get GBR, i have a TW fron and GBR rear and think the GBR is much better overall. As far as trial and error, try getting something used first and see if you like it, if not, then buy something else, its much less expensive that way if its wrong. Sometimes what doesnt work for one truck will work on another.

 

[Steve Rupp]

Gary, Don't bother with a double cardon rear. With a 3" lift you're going to need to pull the pinion way up in order for it to work properly. This means you will need to relocate your a-frame. You can't pull the axle in far enough to get the proper angle with the stock links. Like my brother and Marc said, going with the dc shaft may cause more problems than you want to deal with. I tried it and went back to the double u-jointed. With a 3" lift it's not needed.

Now as far as who to get it from, GBR. Call Bill up, let him know what you have and what you're trying to achieve, and he'll let you know. Just make sure you have some time to talk because he's got the gift to gab. Get the double u-jointed shaft with links and be done with it.

 

[Steve Rupp]

Here's my setup with a 4" lift:

 

[Steve Rupp]

This one might show the angle better:

 

[marc olivares]

I was just trying to avoid the trial and error metod, but that seems to be the way it is with these rigs. I will get a DC rear shaft and we'll see what happens!

Now all I need to do is decide on TW or GBR!

Thanks for the input.

it's obvious that you just want to spend money you don't need to and tell everyone about... i can't think of a better reason why you would post a "need advice" thread and do the opposite of what many people (who have the same lift or more) advise.

for about the same money as a D/C shaft, you can buy a standard u-joint shaft and adjustable RTE rear links.
again, on a Disco, DC rears and Multiple d/c fronts are not problem solvers. the vibes will continue...

i've setup many vehicles with your intended lift, and D90s are the only vehicle that benefit from a D/c rear shaft.

correct the pinion angle and use a standard shaft.

 

[PCFRover]

it's obvious that you just want to spend money you don't need to and tell everyone about... i can't think of a better reason why you would post a "need advice" thread and do the opposite of what many people (who have the same lift or more) advise.

Marc, You read me completely wrong on this, I just want to do it right the first time if possible. After reading old posts I became confused, that is why I was looking for advice and info. My initial conclusion here was incorrect and has been corrected.

As it turns out this thread and another one on drivetrain geometry have finally given me the explanation of why the way to go is with a standard U-joint shaft and rear links. I was looking for more than the basic "do this cause I did" response and finally did get some good info to base a decision on.

Thanks to all for your input on this.