Thread: D2 front drive shaft problem?

I had the chirping noises on load within a week of Teflon being stuck in a dam. I went for a genuine replacement from ATV $650 Since then I've noticed vibrations between 2400-2600 rpm which is being investigated now.

2" lift, 265/70-16 tyres, reasonable amount of offroading in the last 12 months since I've had it. 116,000 kLM

Originally Posted by Slunnie

I'm not sure that I agree with this, as it is not a situation that is duplicated at the rear, where the single uni deals with the entire lift, as opposed to the DC which divides the angle between each uni. The other interesting thing is that the rear shaft sees significantly great forces through it when compared to the front, and I am assuming that impact forces are similar due to the use of lockers.

The thing that makes me tend to think that driving conditions and style is a greater factor than lift though, is that since reducing the number of TT's, the shafts have been lasting significantly longer. But that said, I do agree that the lift increases the wear in the uni joints.

I can't visualise the relative lengths - but isn't the rear shaft on a Disco quite a bit longer than the front one? Which means the angle is significantly less, although you are right, the double cardan joint means it is shared between the two joints, although any wear on the centering mechanism allows the possibility of destructive vibration that is not there for a single joint. Also, is the crankshaft and hence transfer case shafts horizontal? or inclined back slightly, which would also increase the angel on the front shaft compared to the back.

Lifting is a major factor in U-joint wear - the larger the angle the more rapidly they wear in any application. I'm not too sure how much of a factor impact forces are, although as soon as there is wear and hence play, impact forces will have a major part to play in failure. Also, would lockers make the life of a prop shaft U-joint harder? To the extent the locker prevents loss of traction and sudden gripping, I would have thought it would help (of course the effect on the half axles is different). I also would have thought that dust was fairly well excluded from modern U-joints, although the same can perhaps not be said for water and mud.

John

Originally Posted by JDNSW

I can't visualise the relative lengths - but isn't the rear shaft on a Disco quite a bit longer than the front one? Which means the angle is significantly less, although you are right, the double cardan joint means it is shared between the two joints, although any wear on the centering mechanism allows the possibility of destructive vibration that is not there for a single joint. Also, is the crankshaft and hence transfer case shafts horizontal? or inclined back slightly, which would also increase the angel on the front shaft compared to the back.

Lifting is a major factor in U-joint wear - the larger the angle the more rapidly they wear in any application. I'm not too sure how much of a factor impact forces are, although as soon as there is wear and hence play, impact forces will have a major part to play in failure. Also, would lockers make the life of a prop shaft U-joint harder? To the extent the locker prevents loss of traction and sudden gripping, I would have thought it would help (of course the effect on the half axles is different). I also would have thought that dust was fairly well excluded from modern U-joints, although the same can perhaps not be said for water and mud.

John

Both shafts run a decent angle through them at the transfer. The length are different, but the rear isn't a lot longer and the angle through the rear uni will still be more than that through the each uni in the front DC. Any vibration is shared through the driveline through the centre diff. I tend to think that the locker make life easier on the propshafts. Oh well, where water and mud will go, dust will be there before hand.

Shaft died at 110,000km - 2002 D2 TD5

Pretty standard suspension set up
Lots of off road, some harsh first 90,000k, not much the last 20k

Gibbs Truck repair at Burleigh, did a great job, completely refurbed/recreated for $265.

Details here http://www.aulro.com/afvb/discovery/...tml#post786429

Originally Posted by Slunnie

Both shafts run a decent angle through them at the transfer. The length are different, but the rear isn't a lot longer and the angle through the rear uni will still be more than that through the each uni in the front DC. Any vibration is shared through the driveline through the centre diff. I tend to think that the locker make life easier on the propshafts. Oh well, where water and mud will go, dust will be there before hand.

I still reckon it's the way you drive

This one for Pierre and Slunnie,,

did the 1310's make a big price change?
are they a common part?




and this for the engineers

will going to a bigger uni make a practical difference?

Originally Posted by Redback

I still reckon it's the way you drive

I would say that it is the due to the conditions that we are forced to enjoy driving and so look to pass on the costs involved.



But you're probably right.

Just adding my experience (Disco 2003 Td5)
Proactive advice from MR Redcliffe on 90000K service.
Replace front uni joint at TC end of front drive shaft as it is a sealed unit and cannot be greased, seizes up and buggers the box and everything related.
U bet, done with a heavy duty, greasable defender UV joint, $58 part, $60 labour, well done MR.
Steve