driveshaft phaze

[muskyman]

ok I know a little vibes messes up the mind of even the hardest core Land rover guys?

my 94 disco has almost no vibes

but while under it the other day I noticed the strangest thing

the front drive shaft is in there outa phaze( the yokes are not lined up)

I have been wheelin forever and have a pretty good concept of the workings of driveshafts .

and I would never run a single cardin style shaft in any other way then lining up the yokes, but yet it seams I am

is this some top secret rover thing I dont know about?

or did some shmuck at the factory miss on the lining up part?

hell who knows maybe this answers all the vibe questions land rover people are all bitchin about?

[Rover Addiction]

Ok, here's a little secret that rover doesn't want you to know: They didn't line up the front t-case output with the front pinion yoke left to right. The front driveshaft is turned slightly to one side. Without getting into the technical explanation of rotational motion and u-joint theory, the short answer is: the yokes on the shaft are intentionally out of phase such that they eliminate the vibrations that would normally come from this type of mis-allignment.

Yes, it works very well in this case. No, it's not the best once you start lifting the truck and changing suspension geometry.

Does that help?

-John

[muskyman]

well sorta

I noticed that the pinion is not lined up

it really does not need to be in a single cardin style shaft

it needs to have the drive and driven flanges parralel

in a cv/double cardin style they need to be lined up

I keep hearing that guys want to go to cv style front shafts.

this cant be done with off set pinion and transfercase so I wonder what these guys are thinking?

adjusting the pinion angle up and down to aquire the needed less then 2 degrees pinion to shaft under load to make a cv work still does not change the side to side issue. it needs to be less then 2 degrees side to side as well as up and down

guess that explains all the vibe issues in a higher mileage disco, running outa phase they are gonna wear u-joints and cause vibes.

[Rover Addiction]

My understanding is that because of the multiple angles involved, the rover solution is changing the phase of the single cardan driveline. Yes, the double cardan driveline runs into slight vibes due to the misallignment of the pinion and t-case output, but I haven't really had too much of a problem. At least, much less of a problem than when running the stock single cardan shaft on a 4 inch lift D90. Those don't last long at all!

-John

[muskyman]

in a vehicle that has a large lift double cardin is the best way to go IMHO even if you are outside the optimum drivline angle.

I have put CV style shafts in almost all the set up trucks I'v done

but to think that land rover came up with this as a solution on a full time vehicle is kinda stupid

sounds like a short sited decision of a pencil pusher not a true fix by a slide ruler guy

then again maybe its planned profit for the service departments


well guess this makes the 40 spline ford 9" sound like a better idea.

are you running stock axles under your defender?

[Rover Addiction]

To tell you the truth, I think the Rover fix to the problem is an elegant solution. Keep in mind, these trucks are meant for expedition driving. High loads, long distances. The more complicated your truck is, the more likely it is to break and the more parts you have to carry. Rover never intended for these rigs to be lifted and run with huge tires. Yes, it can be done and they work pretty well, but some things need to be changed in order to fit the new purpose of the rig.

I'm running the stock axle housings with GBR 4.1 gears, ARBs front and rear, GBR heavy duty 24 spline rears, and GBR heavy duty treated 32 spline CVs and axleshafts in front. Seems to be working pretty darn well to me. I do break things, but that's bound to happen when you're running heavy beadlocked 37" tires and a supercharger on rocks. Even the big boys with rockwells break things.

-John

[muskyman]

the fact they live at all is a testament to the quality

thats a wild sounding truck

[Tdi Guy]

I took my shaft apart and forgot how to put the front back together(out of phase).... How many splines out should it be?

[fridgefreezer]

I wonder if the pinion is off centre because the whole axle is over to one side - if you look at a RRC and note how the wheels line up with the bodywork the front axle is around an inch over to one side. IIRC it's down to the panhard, so as the suspension cycles it works out about right.

Can you tell I don't do coilers?

[Dougal]

Originally Posted by Tdi Guy

I took my shaft apart and forgot how to put the front back together(out of phase).... How many splines out should it be?

I searched high and low for this about a month ago. I noticed the previous owner of my truck had the driveshaft aligned knuckle to knuckle. Height wise my vehicle has about 2" of lift which was probably the only thing saving it from serious vibrations (that and 1/8 turn of play in each diff).

They're supposed to have alignment marks (couldn't find any on mine either). I put mine in two splines clockwise which is about 45deg. It looked about right from the pictures I found in the RAVE CD.

Muskyman, a solution like this never comes from a bean-counter. An excellent and elegant solution to quite a difficult problem. These chassis were designed in the 1960's and are still in production. If it was a problem it would have been changed long ago.

[Puffdragon]

Sorry rover addiction, your info is a bit wrong. You were on the right track, but it is not due to the shafts being offset left to right. Its due to the pinion pointing up and the t-case output pointing up. This causes a compound angle. Your yokes can be offset side to side as much as you want within reality, but the moment you add a compound angle, your screwed. Rover did an incredible job in my opinion to fix this problem. I might have done it a bit different, but it works.

[Discosaurus]

All you guys realize you're commenting on a 5-year-old thread, right ??

[SlowRVR]

Timely for me though. I'm glad I didn't listen to the provincial safety inspection mechanic the other week who almost threatened to fail my truck for the front shaft being out of phase

[Dougal]

Originally Posted by Discosaurus

All you guys realize you're commenting on a 5-year-old thread, right ??

Nope.

But tdi guys question was fairly new.

[evilfij]

My fault, I referred Tdi guy and told him there was a thread on driveshaft phase over here. Did not realize it was 5 years old. I guess have the memory of an elephant.

I thought there was a calculation for driveshaft phase here somewhere too.

[RoverDan]

Originally Posted by Puffdragon

Sorry rover addiction, your info is a bit wrong. You were on the right track, but it is not due to the shafts being offset left to right. Its due to the pinion pointing up and the t-case output pointing up. This causes a compound angle. Your yokes can be offset side to side as much as you want within reality, but the moment you add a compound angle, your screwed. Rover did an incredible job in my opinion to fix this problem. I might have done it a bit different, but it works.

Finally the voice of reason. I started reading at the top and was wondering how long it would take.