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Prop shaft unis phasing question.
Posted: Tue Dec 05, 2006 8:03 am
by up2nogood
The rear prop shaft on my two Discoveries are in line.
The odd bit is the front prop shafts (in both cars) are out of phase one or two splines.
Are the front shafts out of whack? Or is this a Land Rover oddity?
Posted: Tue Dec 05, 2006 8:11 am
by chimpboy
They should definitely not be out of phase. They need to be parallel for the two universal joints to compensate each other - universal joints turn faster/slower at different points in their rotation.
Good writeup here:
http://www.pirate4x4.com/tech/billavist ... ndex2.html
Jason
Posted: Tue Dec 05, 2006 8:18 am
by up2nogood
That's what I thought, but it's odd for both Disco's to be out on the front shafts.
Thanks for that!
Posted: Tue Dec 05, 2006 8:22 am
by chimpboy
Well, it IS weird if both are out of phase the same way. So maybe a LR guru can shed light on it, but it doesn't make any sense to me, I would expect it to give a vibration kind of feel to the front when 4WD is engaged.
Posted: Tue Dec 05, 2006 8:25 am
by bazooked
all the rangies, discos, are out of phase on the front shaft its how the come out from factory, if u put them in line they will vibrate,.
Posted: Tue Dec 05, 2006 9:15 am
by chimpboy
That's pretty weird... is there another u-joint somewhere in the system we don't know about?
Posted: Tue Dec 05, 2006 10:50 am
by up2nogood
Nope. Funny that they vibrate if aligned.....
With a 2" lift they vibrate anyway. At least they do with the shafts the way they are in my cars.
I wonder if the world will end if I align them? Anyone know if Range Rovers are out of phase or if any other make is set up out of phase from factory?
Posted: Tue Dec 05, 2006 11:16 am
by christover1
Maybe the shafts don't run in line with the drive, ie more than 1 angle from out put to diff input?
This may be a reason to run out of phase.
Just a wild slightly educated guess

Posted: Tue Dec 05, 2006 11:33 am
by up2nogood
Probably a correct guess!
So all Rovers are out of phase.
Buggers!
Posted: Tue Dec 05, 2006 11:38 am
by ISUZUROVER
Yep, you are right Christover - the nose of the front diff points at the transfer case (0deg angle). So installing the propshaft unis out of phase solves any vibration problems from the diff angle.
Posted: Tue Dec 05, 2006 12:26 pm
by Reddo
whaat......
I can't agree, our D1 has them in phase - as they are/were on the vehicle as bought....and even with 2' sping lift and 2.5" body lift there's no bad vibes.
I ascertained some time ago that LR only odd-phased UJs on some Rangie models and even then no-one knows why. Put them in-phase as they should be so that any vibes cancel out and see what happen. I can assure you we have ours in phase and there are no issues concerning bad vibes.....
Check to see if other issues are causing the probs...
Posted: Tue Dec 05, 2006 8:03 pm
by frp88
When i was working for driveline services meny a moons ago we did the army landys they were all in phase even the 6 wheel drives with the short diff shaft.
Posted: Tue Dec 05, 2006 8:19 pm
by rvh96
they are set out of phase to compensate for the different angle between the unis,landrover tried it first on the defenders several other manufacturers have tried this as well ,holden for one on commodore vl to vt, doesnt really work that well though it only changes the speed of the harmonic shift, slower if you advance the unis faster if you retaird so they advance as the vib is less noticable at low speed and less stress on driveline
Posted: Tue Dec 05, 2006 9:03 pm
by J Top
The discos are also plastic coated on the splines and don't go together in any but the factory phase nicely as they tend to bind
J Top
Posted: Wed Dec 06, 2006 2:01 pm
by Hekta
chimpboy wrote:Good writeup here:
BillaVista is teh

at tech articles
Posted: Wed Dec 06, 2006 4:16 pm
by J Top
Posted: Thu Dec 07, 2006 4:49 pm
by rick130
out of RAVE
The front shaft which is shorter than the rear is
’phased’, with the joints at each end, A and B
mis-aligned as shown.
The phasing is necessary on the front shaft only to
allow for greater variation in angular changes.