UJ's ... again !!!

Bloody feckin' useless lumps of feckin' cheesy steel. Rear (front prop) UJ has gone again. I think I've replaced them all now in a year. Bought a pair of UJ's just in case one was much older than the other and will replace as a pair ... but ...

Anyone got a clue why they would go frequently?

When i replace them I pack more grease in, make sure the grease nipple is in properly _and works_ and regularly clean and grease them, esp. after wading/muddy off-roading. I always tighten them correctly and check they're still tight a hundred or so miles later, and again after every wading/mud session.

I am of the opinion that maybe the propshaft might be bent, twisted or otherwise fecked, would anyone agree with this or have any other ideas? At a quick glance it doesn't appear to be ... could the yokes go out of line?

Cheers ... ;)

Reply to
Paul - xxx
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When it comes to UJ's always use genuine parts, If you have then like you I'd suspect something amiss elsewhere. Does the prop telescope ok?

Is it mainly the front and if so have you a lift.. whats the prop angle look like in to the diff?

Lee D

Reply to
Lee_D

I use GKN Part No RTC 3458G .. told by local (mostly pretty damn good) LR people that they are the 'best' UJ's, so I believed them.

Yep, mostly front, no lift as such but HD springs on so maybe 1" lift as I don't have a winch. Prop angle and everything else looks 'normal'. I've had a look at the run-out and the prop isn't bent, it telescopes smoothly, with a bit of force, and all looks well. No scoring on yokes, indeed they lood bloody good.

Could the propshaft go out of balance, maybe? I'm beginning to think I've just done something wrong in assembly, but I can't see how or what!! I'm clutching at straws as we're touring France soon and want to get it ready, correctly, in plenty time.

Cheers, Lee.

Reply to
Paul - xxx

If the prop was bent, or not true you'd know about it....

Id wipe that from your mind :)

Reply to
Mark Solesbury

Have you ever had the front propshaft in two halves? If you have pulled one section out so far that it's separated from the other, at least enough to turn and for you to push it back in a few splines off from where it was, that might cause it. The front propshaft's UJ yokes aren't supposed to be lined up in the same way the rear is, they are supposed to be offset from each other to allow it to work through tighter angles although I wouldn't have thought that element would come into play unless you regularly reached the limits of movement of the prop shaft.

Balance-wise though, could be a problem, there are balance weights on mine, perhaps you can get yours rebalanced at where-ever the hell you get such things re-balanced!

Reply to
Ian Rawlings

Place in Sheffield does it.

Reply to
Nige

Can you state that clearly for me Ian, and would it apply to a 101 ? The Yokes on the prop should be how far out ? 90 degrees, or just a bit ? Why should the rear prop be lined up ?

I've been told conflicting things about this, and mine are both lined up. Thanks Steve

Reply to
steve

Can you describe the nature of the failure? Is it the bearings or the bearing housing/yoke? If the bearings, how did they fail? What does the grease look like when you disassembled the UJ.

What sort of grease are you using? Does it contain Moly Disulphide?

These are UJs with grease nipples. When greasing do you ensure that clean grease comes out at all bearings?

Is there any vibration? All talk of bent shafts, incorrect UJ orientation etc. is unlikely to be the cause without vibration also being evident.

When you compress the shaft does it stay compressed when you let go or does it spring out again?

Is the shaft too long? Disconnect one end and fully compress the shaft - how much clearance do you have?

Off-road use does tend to result in a much shorter life for UJs whatever you do with them.

Reply to
Dougal

Well basically, the UJs on the landy propshafts aren't continuously variable joints, if you force them to work at an angle (as they normally do) then if the driven side turns at a constant speed, the other side of the joint will "pulse" faster and slower as the joint rotates. To cancel this out, on the other end of the propshaft you line the other UJ up so the pulsing from one is cancelled out by the pulsing from the other. This unfortunately means that the angle the shaft works through is lessened, so on the Defender, the front prop shaft ends are not aligned, the two yokes that hold the UJ are offset by about 45 degrees. In theory this should mean that the front axle gets a pulsing drive, it seems it's not noticable though, I've never noticed anything too bad.

All the above knicked directly from the Defender service manual, page

172, Propellor Shafts.

And for reference, "lined up" means that both yokes on the prop shaft are vertical at the same time as each other.

No idea if the above is needed on the 101, the misalignment is only done on the Defender front to increase the angle the shaft can work through as it's so short.

Reply to
Ian Rawlings

Shafts should be marked either side of the sliding joint (usually with arrows) to indicate the correct position of the ends. You line up the marks on the two parts, naturally!

In most cases the ends are 'in line' as on your rear prop - this gives a true constant velocity of transmission provided that the angles of the shaft into the diff and out of the transfer box are the same.

RRC, Disco and several other LR front shafts have the ends deliberately 'misaligned' by somewhere between 30 and 45 degrees (actual value not known). This is a phasing issue to make the best of an imperfect installation - the equal angle criterion mentioned above is not met. It's not to avoid a clearance problem at high angles.

I don't know what the correct setting is for a 101 front shaft - my guess would be that they are 'in line' and do not follow the pattern of later vehicle front shafts. If your shaft is correct for the job (i.e. it's a genuine 101 front shaft) just line up the arrows as described and all's well.

Reply to
Dougal

Someone is missing the main point. The reason that the yokes and U/Js are lined up is because the rear diff flange and the rear gearbox output flange faces are parallel and as Ian partly explains in the next paragraph the effect of the acceleration and deceleration of the centre portion of the prop is totally cancelled out by this arrangement.

This cannot be achieved in the front prop as the front diff is angled upwards and consequently the drive flange faces are NOT parallel. A compromise is then made and the yokes at each end of the front prop are usually arranged approximately 60/30 degrees which works quite well but it has nothing to do with the LENGTH of the prop.

I suspect that as you are introducing too much grease into the joint on assembly, you are probably unseating the seals and allowing the ingress of dirt of the abrasive sort when offroading. It's not wise to pump in too much grease when servicing either, just 'until you can hear the bacon frying' as they say.

Martin

Reply to
Oily

According to the landrover workshop manual;

"The phasing is necessary on the front shaft only to allow for greater variation in angular changes".

So, that clears up nothing then ;-)

Reply to
Ian Rawlings

And there's nothing clearer :-)

Reply to
Oily

I think this is hitting the nail on the head.

Just took the prop off and looked at it properly and it all looks fine, balance weights as described, yokes (mis) aligned as described with no chafing or wearing, simply one side of a UJ gone a tad rusty looking. The side of the UJ that's failed had big (marble size) blobs of grease and 'muck' on the outside, like a hardened paste, but the rollers are brown with rust !!! I suspect Manbys' mud did the deed, it was like wet cement and dried to a very hard crust everywhere else.

Phew .. so it's likely to be my cack-handedness doing it to the UJ's, It'll teach me.

PS, big up to the Difflock people for their prop-shaft tool ... (

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) ... what adifference that made, eight bolts undone in 8 minutes and prop offwithout having to move the thing back and forwards, a bloody revelationand highly commended to anyone doing any work to their propshafts.

Reply to
Paul - xxx

Small price to pay for a good day out. :-)

Reply to
Oily

Heh, weekend actually, and there were other casualties ...

Bent my steering guard, but not the rods so that did it's job well .. We dropped off a hill and the front landed with a huuuuuge bang ... all the lights came on and couldn't turn them off, hazards etc etc and horn ... alll the electrics seemed frizzed, then about a hundred yards later it all stopped and worked fine .. no idea what happend, presumably something un-seated then re-seated itself, probably the whole bloody fuse box ... ;)

Got a new 'hidden' and demountable towbar fitted, with some diesel tank protection ... good timing as the mud was forced up behind the towball socket and out of the recovery shackle my bro' made me to fit in it's place ... looks like the Scorpion Racing stuff but made a tad larger and stronger ... ;)

Had to change the serpentine belt later too as it wouldn't stop squeaking whatever we did with graphite powder or anything ... new 'old' one worked 'till I get a real new one. We also think this is where we bent a front (nearside) shock, pushed the front bumper light mounts into the bonnet and gained another scratch or two ... so not quite the cheapest weekend ever.

but fun ... ;)

Reply to
Paul - xxx

... and you still need to ensure that all four bearings on each UJ receive grease. Lever the spider across when greasing (don't damage the seals) until grease shows at each seal in turn. Don't be too enthusiastic as Martin cautions. The fact that you have had a single bearing failure points to uneven grease distribution.

You'll find it easier to do this is the propshaft can be turned whilst greasing the UJs.

Reply to
Dougal

I couldn't understand why rear wheel bearings on my Passat lasted such a short time, I must have changed them three times in 12 months. I was using a grey/black grease as it's what I had lying around in the garage.As soon as I bought some new Axle Grease to use - lo and behold, they stopped breaking.

Just a thought.

Peter

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Reply to
Peter

Bloody catastrophic matey, cata friggin' strophic ... ;)

Pics on Flickr ...

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Looks like 'cheesy steel' might have been right .... or maybe a roller failure chewing it up. All other ends look fine, greased OK, indeed this one looked well lubed, it was just dug away ... ;)

Castrol LM .. dunno about the Moly. Any recommendations?

Yup.

You're right, the only vibration occurred when the UJ had already failed, the prop is absolutely fine. Just tried it out after replacing UJ's and all is well again at any speed or condition.

Stays compressed.

Loads, about an inch, maybe inch and a half, maybe a bit more.

Heheheh, I'd tend to agree with that ... ;)

Reply to
Paul - xxx

Yes, it's broken!

All sorts of possibilities - roller failure, missing roller(s), heat treatment failure in manufacture etc.. We'll never know.

Castrol LM (the yellow stuff) doesn't contain Moly.

Just an observation that highly loaded rolling element bearings lubricated with a Moly grease can fail as the rollers may skid rather than roll. The whole can then get rather warm and the end is not long in coming.

Not an issue here.

I think that last night's exchanges probably explain the likely cause. I suppose that it is now a case of wait and see. Good luck!

It can also be affected the other way: pull it out and it is 'sucked' closed again.

This was to check that there was a vent hole in the sliding portion. If air can't enter and leave freely there can be end loads on the UJs which they are not intended to take. Sliding joints which don't can have a similar and even more obvious effect. UJs and bearings either side of the shaft can be affected by these problems.

More than enough. Just to confirm that the wrong shaft had not been fitted.

Reply to
Dougal

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