Thread: Front Propshaft on Defender

Slip joint on tansfer case end.

and don't forget to phase the bugger properly. The uni's must be out of phase (not lined up) or you will get vibration.

Originally Posted by big harold

Slip joint on tansfer case end.

I had a 50% chance that I would get it right. I thought that if I drove through water then water would run down the slip joint. Will turn it around tomorrow towards transfer case.

Originally Posted by rick130

and don't forget to phase the bugger properly. The uni's must be out of phase (not lined up) or you will get vibration.

I had it done by Hardy Spicer. The ends are turned 90% to each other then balanced. If I get vibration then could try moving the yoke a few splines round.

Thanks, David

I don't know about defenders, but 90* out of phase seems too far out for rangies and disco I.

Without going out and checking I think it is closer to 45*.

the alignment, or mis alignments is easy, line em up and phase it like you would normally then off set it one spline.

Man I have been a lucky bas tard..I have replaced about a dozen unijoints and didnt even know about phazing except when using them with photon torpedos. and never had a problem..
So know what is phasing??

"Phasing" is the angular relationship between the U-joints on each end of a prop shaft. Most prop shaft installations are designed so that the gearbox or transfer case shaft and the diff pinion shaft are parallel, so that the angle at each end is the same. In this case, the yokes on each end of the shaft must be parallel to prevent vibration.

The setup in the Defender was designed for the original Rangerover, and the pinion shaft is tipped up to clear the track rod, so the two shafts at either end of the prop shaft are not parallel, there is very little angle at the diff, and all the angle is at the other end. In the Rangerover and its Disco successor the rear end of the shaft had a CV joint to get around this problem, as did the Stage 1.

However, when the 110 was introduced, they had found that an acceptable level of vibration could be achieved by using simple U-joints at both ends and changing the phase slightly. All prop shafts should have marks on the two halves of the sliding joint showing the correct alignment, but this may be missing if the sliding joint has been replaced.

Even on shafts where the joints at both ends are aligned (such as the rear shaft on a Defender), these marks should be used to distinguish the right one of the two possible aligned positions, as this will be the one with the correct balance. As a general rule, before disassembling a sliding joint, either find the marks (may not be obvious, especially if it is rusty), or make your own. If you are just replacing U-joints without parting the sliding joint, then you don't need to worry about any of this - although it is probably helpful to mark the position on the flanges at each end, and, again, for retaining the best balance, mark the two halves of each joint so as to reassemble them the same as they were.

John

Originally Posted by JDNSW

<snip>

However, when the 110 was introduced, they had found that an acceptable level of vibration could be achieved by using simple U-joints at both ends and changing the phase slightly. <snip>
John

and my mate, ex-JRA engineer, worked on the design of the Perentie, (responsible for the t/case/6WD) consulted to LRA on various projects, didn't know this
when re-fitting the front prop to his 110 about ten years ago.
An old drivetrain mechanic tipped him off to where his vibration was coming from.

BTW, he showed me his uni that had died "you do realise they have a grease nipple for a reason , how long's it been since it was greased ?"

We worked out it had been a number of years.