How long should a UJ last

Do you do a lot of off-roading ?
I have 2 Defenders, the one for church I never change UJ's and the one that get's hammered in the muddy stuff quite regulary !

dag019 said:

Always, sometimes pack them with too much grease and have issues with "hydraulic lock" when trying to press them in as it tries to force the excess out of the grease nipple hole. then fit the nipple and grease again.
There is always one or two cups that are dry when it is removed despite regular greasing and the others look nearly new and are full of the stuff.
I grease everything on any reassembly unless there is a valid reason not to. Have a nice selection from standard copper grease to some old fashioned axle grease that is like tar and will never come off!

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OK - it is not through lack of trying then!

Are they drilled properly? It almost sounds like a grease passage issue, grease guns can generate excellent pressure and should be able to push grease through OK but it doesn't sound like this is happening!

discomania said:

OK - it is not through lack of trying then!

Are they drilled properly? It almost sounds like a grease passage issue, grease guns can generate excellent pressure and should be able to push grease through OK but it doesn't sound like this is happening!

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My conclusion is that due to the grease nipple angle it does not equally distribute the grease and it will burst a seal on the easy access cups before fully filling the more difficult ones. Because they get changed regularly they press out easily and I can now swat one over in about 20 min including removal and refit of the prop shaft it is just annoying.

Jason2 said:

Do you do a lot of off-roading ?

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I do enough. It is a daily drive so most of the mileage is on tarmac but I try and get out and green lane at least every couple of months. It is more often if you include wet/muddy grass/field as off road.

Can you see grease pop out all joints?
Spin propshaft & use an openended spanner to relive the pressure on the cup. Pump grease in till you hear it pop/ crack. Try not to pump to much past seals.

dag019 said:

My conclusion is that due to the grease nipple angle it does not equally distribute the grease and it will burst a seal on the easy access cups before fully filling the more difficult ones. Because they get changed regularly they press out easily and I can now swat one over in about 20 min including removal and refit of the prop shaft it is just annoying.

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Probable - but it should distribute out OK. I know 2 cups always ooze first, but I give it a good whack on the grease-gun till it oozes a little from the others.

At least they are easy, quick and cheap enough things to change!

discomania said:

When you fit them are you packing them with extra grease and pumping in some extra with a grease gun? Sounds simply like a lube issue.

A good quality grease is worth while, I have an original can of moly slip that I use a very small amount of for assembly of things, then use normal grease, it makes a marked difference, I have been using it on bearings and in engines (little dab under valve caps, rockers etc.) and all sorts my entire life and some of the stuff I built up with it years ago is still going strong and bearings look brand new etc. I am not suggesting you go to this extent but good grease and plenty of it should work a treat.

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Most grease points on an ordinary vehicle will require LM grease. I decided to use "Moly-Grease" in most applications instead many years ago.
It is LM grease but with molybdenum disulfide (Moly Slip) added to the mix. It looks very similar to the grease supplied in sachets with new CV joints.

I actually keep two grease guns, one with Moly Grease and the other with LM grease. When I put the Disco in for service, I always provide my Moly grease gun for them to use, no trouble.
The cost of Moly Grease is very similar to standard LM grease.

I agree about pushing more grease into the joints before the prop shafts are refitted to the vehicle. The position of the joint while it's just flopping about on the end of the shaft does make filling a lot easier.
Another problem which I have come across is actually getting at the grease nipple. Sometimes they're too short which means that there is just one particular point where the grease gun nozzle will fit properly. I overcame this difficulty by fitting slightly longer grease nipples. Be careful about your choice of grease nipples, too long and they can foul as the U/J is rotating.

Sounds like you are doing all the right stuff. I use the expedition GKN UJs from Island 4x4 - they have metal and rubber seals, supposed to be good. I haven't had a problem in a couple of years, touch wood - but I'm not covering your yearly mileage.

If you have a lift kit fitted and are using oversized tyres they won't last long.

brian47 said:

The cost of Moly Grease is very similar to standard LM grease.

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I know the stuff you are talking about but Moly Grease is not the same as original Moly Slip, i.e. Moly Slip AS40. Moly Grease contains a token gesture 1% molybdenum disulphide. It is still better than regular LM for sure but it is just dosed LM.

I use Moly Slip AS40 or ROCOL MTLM which runs anywhere from £45 a tube to £115 for a small can £1200 for a big can. This is the only stuff that is close to the original Moly Slip and today's formulation is around 40% molybdenum disulphide and 20% graphite.

The issue was they didn't know the value of molybdenum when they first started making this stuff, they knew it was good but not just how good, molybdenum is now one of the most expensive metals in the world - hence the cost of these greases and pastes!

One thing I have noticed is some UJs that are new but been in storage for some time is the grease in them can have gone hard and restrict new grease going in so I poke it out with a rod before fitting.

Have you ever had the splines apart? Is the phase angle as it should be ie. not the same as the rear prop?

Jason2 said:

Do you do a lot of off-roading ?
I have 2 Defenders, the one for church I never change UJ's and the one that get's hammered in the muddy stuff quite regulary !

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Feck me, eye up Jason, nice to see you mate, hows it all going?
(I'm still the only brit in Gerards gang ) Countryland is having a bit of a revival at the moment, must be about 20 of us now.

Something a LR mech told me about (he showed me how to do it) was to use a fine slitting disk in an angle grinder and score a fine shallow groove in the end of the bearing legs, clean off any dust/edges and refit as normal. It is meant to ease the passage of grease from the center to the sides if one of the cups is hard up against the leg.
I probably get to replace at least two joints every couple of years, but it does get off road a bit, and the earth here is very sandy in some of the forested areas so that is a bit of a killer.