FC101 - Woods DC Front Driveshaft

[101RRS]

Has anyone put in a Woods WWW.4XSHAFT.COM double carden driveshaft in the front of their 101? If so how have they found it and has it resolved the '101 rumble' issue.

Thanks

Garry

[Lotz-A-Landies]

A DC joint shouldn't be a solution as the two flanges are parrallel, DC joints are for when you have different angles between the output flange and the diff input flange.

AJ says he has reduced his noise by tilting the engine gearbox assembly down on the RHS therefore lowering the output flange and reducing the height difference.

I have wondered what would happen if you made a prop shaft with two appropriate CV joints instead of the spicer type joints.

(Now if you rotated the pinion angle on the front Salisbury, and made the appropriate counter-rotation to the swivels, then the DC joint shaft would be just the thing.)

[101RRS]

Thanks Diana - does beg the question as to why the D2 and the Stage 1 have DC shafts and their two flanges are parallel.

I am familiar with most of the methods that people have proposed to fix the 101 issue but I have never actually found anyone either here or the UK that have first hand experience in resolving the issue.

Hence my question here to see if anyone has actually used a DC shaft and can comment first hand on its success or other wise. I am not going to spent reasonable $$ on something that may not work. I did that a few years back and got a shaft made on the advice of a recognised "expert" and while the shaft is better than the original it is not worth the money I paid for it.

Cheers

Garry

[101 Ron]

I found a sure fire way to fix the front tail shaft rumble.
it is low cost.
it works.
It has been proven on my 101 for a six month period.
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And the the method is to remove the silly thing....problem solved.

[Lotz-A-Landies]

I know for sure that the Stage 1 doesn't have have it's pinion parallel, it is angled up.

Can't say anything about the Disco pinion however they have rubber donuts instead of spicer joints and I do know that when the ZF conversion happened to my RRc we had to put the front prop shaft out of phase, which is the alternative to a DC joint.

We tried putting Iain's MG II's prop shaft out of phase on Sunday without success (on the noise/vibes).

[101 Ron]

To fix the so called problem with a double carden joint on one end of the shaft and a normal uni joint on the other end is to roll the diff centre which is alot of work.( this is the best method )
The other method is to use a cardon joint or CV joint on each end of the tail shaft, but the limited lenght advailible for the front tail shaft would make that arrangement high wear and if not done right , much weaker than standard.
Another method which would reduce the rumble would be to reduce the weight of the front tailshaft, but that is in the too hard basket too..

.......what is the problem with the front tailshaft rumble........?
nothing really gets hurt ? and uni joints are cheap and easy to do if needed.

[101RRS]

I know for sure that the Stage 1 doesn't have have it's pinion parallel, it is angled up.

Can't say anything about the Disco pinion however they have rubber donuts instead of spicer joints and I do know that when the ZF conversion happened to my RRc we had to put the front prop shaft out of phase, which is the alternative to a DC joint.

I will believe you on the Stage 1 front but the D2 does not have rubber donuts on the front shaft - rear one only.

cheers

Garry

[Lotz-A-Landies]

There is a double CV retrofit for the rubber donut half shafts on the Lotus Elan, so I don't know why it couldn't be done on a 101 prop-shaft, just need stronger CV's.

[101RRS]

Now this is not a post about how do I fix the "101 rumble" but a simple question as to whether anyone has actually fitted a Dc shaft and what was its impact was.

Everyone (including myself) has a theory on how to fix the issue but I have not actually come across anyone that has actually done it.

Not having the front driveshaft in does make the 101 very nice to drive - very smooth and very quiet.

Garry

[101 Ron]

A DC joint shouldn't be a solution as the two flanges are parrallel, DC joints are for when you have different angles between the output flange and the diff input flange.

AJ says he has reduced his noise by tilting the engine gearbox assembly down on the RHS therefore lowering the output flange and reducing the height difference.

I have wondered what would happen if you made a prop shaft with two appropriate CV joints instead of the spicer type joints.

(Now if you rotated the pinion angle on the front Salisbury, and made the appropriate counter-rotation to the swivels, then the DC joint shaft would be just the thing.)

the flanges are not completely lined up parrallel and there is also a slight side ways non compensated off set.
The other problem is when you work 5.56 to 1 diffs at highway speeds with high angles on the unijoints the centre of the tail shaft has to go though four cyclic changes of speed per revolution and inertia forces increase with speed which is why the problem increases with speed.

Another part fix is 4,7 diffs to reduce tail shaft speeds
Another part fix is the over drive if fitted allows power to be placed on the drive shafts longer going down hill as power or torque though the tailshaft tames the inertia buzz on the over run by not allowing the rail shaft to buzz or rattle around from ome side of the crown wheel and pinion teeth to the other.

The above is not here say but automotive fact .
Few people seem to get a handle on really why the 101 makes a tailshaft rumble.
A front tailshaft with a cv.cardon joint on one end must not have the drive flanges parallel and and at different heights or constant velocity can not be achived.( standard 101 landrover arrangement)...............one drive flange must point at the other to achive constant velocity using a CV /cardon joint on one end of the shaft, and therefore the need to roll the front diff if using this arrangement.