Urgent LN106 grinding noise

[Evski]

Hey guys, on the way to work this morning my 1995 dual cab Lux started making a pretty nasty grinding noise. It happens more when the vehicle is under load like engine braking down hills, and doesnt do it as much when coasting down hills in neutral or when the clutch is engaged.

The sound doenst change with RPM, just a constant grinding sound once you get up to say 20km/ph. I have had the brakes and wheel bearings changed 3 months ago by a good mechanic, and we changed the clutch including spigot and throw out bearings around the same time so thinking it would either be the centre bearing or something in the transfer case. It definately sounds like a grinding bearing, and the mechanic did mention that the rubber was starting to perish on the centre bearing the last time I was in, so I am leaning that way. The vehicle drives the same and doesnt vibrate, just the nasty grinding noise.

For the people that have had centre bearing issues in the past, does this sound similar to your experiences?

Cheers
Evan

[Evski]

Nothing? Sorry to pester but I need to sort this out today...
Cheers

[DUDELUX]

Could also be a Uni mate, climb under and check all unis for any excessive play, check at pinions and centre bearing as well.

[Mr DJ]

If the grinding sound dosen't change at all with speed change then it can't be anything to do with revolving driveline, hubs, etc so it is very difficult to guess at the problem.

How are the shocks & suspension bushes ??

[Evski]

Uni's were done not long ago and 'feel' fine, and from experience they sound different to this noise when they go. This is a loud grinding noise, like metal on metal sort of similar to when brake pads go (brakes are brand spankers from the master cylinder to the disks BTW).

The suspension is just over a year old and is in great nick.

I snuck out on my lunch break and had a look at the centre bearing and it looks pretty shagged. There is heaps of movement in it when pushed up and down, and the rubber inside has perished meaning it will need to be changed anyway. It's definately a bearing sound, but isnt the wheel bearings as I had them done not long ago, and the sound didnt change when turning.

Also the sound is definately coming from the centre of the vehicle not the front or rear, so if it's not the centre bearing then my next guess would be a bearing in the transfer case.

Does anyone have a good link for a diy centre bearing change, or is it just a case of removing the shaft, getting a rattle gun on the big nut holding the bearing on, removing the bearing, and putting it back together?

Thanks heaps for the suggestions guys
Cheers
Evan

[DUDELUX]

Ev, pretty much what you said, pull the driveshaft off, then get the centre bearing off with a rattle gun, put on a new one, and put it all back together again.

There is a trick to keep the rubber in great nick, Ive read somewhere on here that alot of the time, the rubber goes to shit long before the bearing will.
If you use a certain type of Sikaflex, and fill up the rubber with it, that will keep the rubber from going soft over time and failing.

Ive heard of people flogging out centre bearings in under 12months, but the rubber has failed, not the bearing itself.
Si filling it with Sikaflex will prevent the rubber going to crap and the whole thing should last longer.

I have some in the shed, Ill go and have a look.

[DUDELUX]

I dont have any in the shed sorry.
I do remember that it is black though, which probably doesnt help much, but Im sure theres info on here somewhere.

I can tell you that you inject the SF into the holes in the rubber until it is full, then let it cure for a couple of days before fitting, and it should be good to go.

[Evski]

Nice one Tony, cheers for that. If it's not the centre bearing then my money is on the transfer case. Luckily I have a set of crawler gears at home, but I'm pretty tempted to sell the Lux so was hoping to get rid of them seperately. Oh well, sh!t happens I guess.

[Evski]

Centre bearing changed, uni's greased, new oil in the transfer, and it's still making the bloody noise. The transfer is getting rebuilt this weekend, as well as a set of crawler gears and twin sticks.

[Evski]

Damn, after all that it turns out to be a CV joint. good excuse for a set of Longfields...