Thread: Vibration in 2WD only! Series II SWB

When you say the front prop is aligned, are the unis in or out of phase?

With the full time 4wd cars you need to run the front prop out of phase or you get vibrations as the pinion angle is incorrect for normal in phase use.
The Stage 1 used a double cardan front shaft to eliminate this.

It all comes down to pinion angle, if the pinion and t/case are in the same line run the unis in phase, if the diff pinion points up at the t/case you'll get less vibration by running the front prop out of phase.

As sort of suggested earlier, has it got springs (front or rear) with a different height to originally, or has it got non-standard shackles, so that the pinion shaft and transfer case shaft are no longer parallel? This would cause the vibration, which is damped by the torque loading if in four wheel drive.

There is a slight possibility that the springs could be set up so that the axle housing is rotated with a similar result. (This would be with the two halves of the spring flexing differently. Most likely if they are poorly designed or made parabolics.

Originally Posted by rick130

When you say the front prop is aligned, are the unis in or out of phase?

With the full time 4wd cars you need to run the front prop out of phase or you get vibrations as the pinion angle is incorrect for normal in phase use.
The Stage 1 used a double cardan front shaft to eliminate this.

It all comes down to pinion angle, if the pinion and t/case are in the same line run the unis in phase, if the diff pinion points up at the t/case you'll get less vibration by running the front prop out of phase.

Not with the landy at the moment but the prop shaft had two arrows on the slip joint and main shaft and they were both pointing at each other I’ll have to see what that means in relation to out of phase or in phase.

But would a faulty or out of alignment front propshaft cause a vibration only in 2wd and not in 4wd?

Originally Posted by rick130

When you say the front prop is aligned, are the unis in or out of phase?

With the full time 4wd cars you need to run the front prop out of phase or you get vibrations as the pinion angle is incorrect for normal in phase use.
The Stage 1 used a double cardan front shaft to eliminate this.

It all comes down to pinion angle, if the pinion and t/case are in the same line run the unis in phase, if the diff pinion points up at the t/case you'll get less vibration by running the front prop out of phase.

Not with the landy at the moment but the prop shaft had two arrows on the slip joint and main shaft and they were both pointing at each other I’ll have to see what that means in relation to out of phase or in phase.

But would a faulty or out of alignment front propshaft cause a vibration only in 2wd and not in 4wd?

I would think the prop shaft would cause a vibration in all forward gears except may be 1st being so low & not high speed rotation. Wonder if the main shaft nut is loose causing the synchro hub to have too much end float causing it to move away from the dog teeth on 2nd gear or rubbing on something in the transmission. I have found this nut to be loose on all the S1's I have owned.

Originally Posted by jessec96

Not with the landy at the moment but the prop shaft had two arrows on the slip joint and main shaft and they were both pointing at each other I’ll have to see what that means in relation to out of phase or in phase.

But would a faulty or out of alignment front propshaft cause a vibration only in 2wd and not in 4wd?

From what I remember a Series has the uni's in phase, ie the crosses line up.
Out of phase as used in an RRC/D1/90/110 have one cross at roughly 30* to the other cross.

I used to get a vibration in my Defender under coast, not power from the front shaft as the pinion to t/case output shaft angles were worse than stock as it was lifted.
Coast = 2wd as the diff is driving the prop.
As John mentioned, have you installed new/lifted springs?

Originally Posted by rick130

From what I remember a Series has the uni's in phase, ie the crosses line up.
Out of phase as used in an RRC/D1/90/110 have one cross at roughly 30* to the other cross.

I used to get a vibration in my Defender under coast, not power from the front shaft as the pinion to t/case output shaft angles were worse than stock as it was lifted.
Coast = 2wd as the diff is driving the prop.
As John mentioned, have you installed new/lifted springs?

Yes. Series have crosses in line (except Stage 1). To amplify this, the yokes on each end of the shaft, i.e., on the propeller shaft must be in the same plane.

Since it is a new shaft, consider the possibility that the arrows are in the wrong place, due to confusion with the 110 in manufacture.

exc;uding vehicles fitted with double cardens.

if you have a series then all UJs line up on the shaft, if you have a constant 4wd then the front shaft is out of phase (depending on lift, setup its 1-3 splines) unless you have a rangie with the VC in which case almost anything goes some like the ujs in phase others want them out.

I would be pulling the shafts and checking the Ujs sometimes you can get one sticking side, the slip joint can also cause issues if its sticking.

It could also be the flange on the front of the Tcase and believe it or not the handbrake setup.

you could have a wheel balance issue or a suspension bush on the way.

Due to there being no way for the driveline to unwind when a series is in 4wd the resulting loadup on the driveline can cancel out lots of little things just by keeping the suspension in a more torque reactive condition