Ratchety chattering noise from front in 4WD

[schultz]

Hello,for obvious reasons I've been running my Terrano 2 in 4WD a lot lately. It performs fine when the road is totally snow covered, but as soon as I get to a wet bit of road where snow has melted I get the above noise, particularly when easing off the throttle on the run over. I then have to revert to 2WD till I get to a bit more snow, which is a bit of a pain.
I gather it may weel be the free wheeling hubs, but what particularly is causing it?
Would the fact that I have 235/75/15 tyres on the back and 215/80/15 on the front have any bearing on the matter?
Thanks,
John

 

[jims-terrano]

You should really have a balanced set of tyres, certainly don't mix on the same axle. Theres a few threads running at the mo with similar issues. One rule of thumb these vehicles should not be run on a hard non slipery surface in 4wd as you'll get whats called transmission wind up and risk damaging something. Chances are your auto hubs need a good dose of looking at, again see other threads and also the workshops within downlaods in Quick Links.

Jim T

 

[Andy-Blackpool]

Mine has done the exact same thing, forgot to put it back in 2h after I got out of the snow and about half mile down road it made a right racket so pulled over and put it in 2h then drove off, not heard noise again

 

[dinky]

Hubs not releasing properly,when you reverse do it in a short burst

 

[Andy-Blackpool]

Hubs not releasing properly,when you reverse do it in a short burst

My hubs wouldnt release though as I still had it in 4H when it made the noise, when I stopped and put it in 2H the noise went

 

[PCshedman]

I must be unusual as not only do my hubs not click when I reverse, but I recently drove home on a slightly wet M62 for 25 miles in 4H as I wasn't sure when I would meet slush/snow along the journey. Didn't hear any noises and it seemed to drive fine. In the handbook it says you can drive on Motorways in slippery (but not necessarily snow) conditons.
Have I done something wrong?

 

[tezzer]

I must be unusual as not only do my hubs not click when I reverse, but I recently drove home on a slightly wet M62 for 25 miles in 4H as I wasn't sure when I would meet slush/snow along the journey. Didn't hear any noises and it seemed to drive fine. In the handbook it says you can drive on Motorways in slippery (but not necessarily snow) conditons.
Have I done something wrong?

i dont you have any problems, you would normally get wind up and would slow you down and poss breakage, i would'nt worry about it now. :thumbs

 

[PCshedman]

Thanks for that. Only difficulty I have had in the snow has been when doing a very tight downhill reverse into deep snow on my drive, using 4H. It feels like it is going over a big stone or something.
Pther than that, just need a petrol generator running in the back to run an electic fan heater to keep warm!

 

[lacroupade]

I must be unusual as not only do my hubs not click when I reverse, but I recently drove home on a slightly wet M62 for 25 miles in 4H as I wasn't sure when I would meet slush/snow along the journey. Didn't hear any noises and it seemed to drive fine. In the handbook it says you can drive on Motorways in slippery (but not necessarily snow) conditons.
Have I done something wrong?

I've done more than 250,000 miles in these trucks and used 4WD a lot on the road when its been peeing it down.

You won't break anything unless you start doing donuts on a bone dry road to be honest - highly unlikely on the M62.

 

[PCshedman]

Good that's re-assuring. Members like you have been very helpful. So glad I joined as new ownership of an old vehicle can be puzzling!
Still thinking about that generator in the back though.............

 

[jims-terrano]

Thanks for that. Only difficulty I have had in the snow has been when doing a very tight downhill reverse into deep snow on my drive, using 4H. It feels like it is going over a big stone or something.
Pther than that, just need a petrol generator running in the back to run an electic fan heater to keep warm!

Mines just the same when I reverse too. Told you all before with a clean pollen filter and an 88 degree stat my car is toastie warm:thumbs

Jim T

 

[rustic]

Other than that, just need a petrol generator running in the back to run an electic fan heater to keep warm!

I have the same model, the problem is the viscous fan, it air cools the engine bay like nothing else, at this time of year I place a piece of plywood behind the grille and helps the upper part of the radiator get warm.
To remove the grille, use a long flat blade screwdriver on the 4 small plastic screws on each corner, turn each screw about 45 degrees, then go to the centre fixing from inside and you can release it by pressing on the top/bottom of the clip. When removed there is an M6 threaded nut on the vertical bar that you can bolt a piece of plywood to. I sprayed mine matt black. I also fitted spot lights behing the grille. Inside gets much warmer, but I do notice an increase in engine noise I guess cause by reflection.
I made another panel for the lower part, but it has never been that cold YET !!!:augie

Rustic

 

[lacroupade]

Good that's re-assuring. Members like you have been very helpful. So glad I joined as new ownership of an old vehicle can be puzzling!
Still thinking about that generator in the back though.............

I'm a bit surprised - its not the worlds greatest heater but once it gets going its fine...in fact without proper circulation this engine boils up really fast, so its not down to a lack of hot water.....

Have you checked your thermostat (cheap and easy to replace so worth doing just for the hell of it frankly)? And squeezed the hoses for air locks?

And checked the level in the rad itself ( as opposed to relying on the expansion tank)?

Re your issue with the bump on reversing, its still possible to get wind-up even in snow when performing tight manoeuvres. Worth changing your rear diff oil - make absolutely sure its LSD oil, nothing else will do, and you need about 2.8 litres....it make a lot of difference to the rear end and probably hasn't been changed in yonks.

Main tip is make sure you can undo the filler before removng the drain :thumbs

 

[PCshedman]

Great tips -only topped expansion bottle so will try rad tomorrow.
When weather gets better will change engine oil and filter. looking at the filter, it looks a bit tight to get a removal tool on it? Also, am I ok to use mineral diesel oil or should it be semi-synthetic? Mileage 186000

 

[danielj]

I'm a bit surprised - its not the worlds greatest heater but once it gets going its fine...in fact without proper circulation this engine boils up really fast, so its not down to a lack of hot water.....

Have you checked your thermostat (cheap and easy to replace so worth doing just for the hell of it frankly)? And squeezed the hoses for air locks?

And checked the level in the rad itself ( as opposed to relying on the expansion tank)?

Re your issue with the bump on reversing, its still possible to get wind-up even in snow when performing tight manoeuvres. Worth changing your rear diff oil - make absolutely sure its LSD oil, nothing else will do, and you need about 2.8 litres....it make a lot of difference to the rear end and probably hasn't been changed in yonks.

Main tip is make sure you can undo the filler before removng the drain :thumbs

The man is right about these generating a lot of heat. If water was low they can build up mighty heat. Recently put an 82 degree stat in mine and have no problem with heat (changed down from 88 as I don't like too much heat while driving).
I used to check for air lock in system by opening radiator cap and blowing into cap of expansion bottle and see if I got bubbles at the radiator top. Don't know if this method actually works but logically I thought it should show that the fluid has passage through the system. Where is your temperature guage needle on the guage when warmed up? It should be in and around the half way mark.
Would think it wouldn't be unusual to get a bump on reversing if your are turning fairly sharply at the same time. I presume it's not a bump from the front you are feeling from the steering stops (or whatever it is they are called). They can make an awful bumping and grinding but grease will help that.
Would be no harm at all checking and replacing differential oil if you don't know for certain that it was changed relatively recently. I would suggest that you also have a suitable filling can handy as it can get very messy and a lot of LSD oil can be wasted trying to get the oil in the filling hole without a proper can. You could make up a funnell if you don't have the proper can (I made one out of the top of a plastic drinks bottle and a piece of garden hose but this would also be messy unless you have the car lifted to give you pouring room).
My motor is at about 120,000 and use 10w40 semi-syntethic at last oil change (Bardahl diesel engine oil I think). Think it takes about 8 litres.

 

[lacroupade]

Great tips -only topped expansion bottle so will try rad tomorrow.
When weather gets better will change engine oil and filter. looking at the filter, it looks a bit tight to get a removal tool on it? Also, am I ok to use mineral diesel oil or should it be semi-synthetic? Mileage 186000

http://www.commaoil.com/motorists

Put your reg and postcode in and it tells you what oil types you need and where to get them....:thumbs

 

[PCshedman]

Great link -seems like I need the semi-synthetic -pity as I have some mineral oil left from when I had my Vectra diesel!

 

[schultz]

Thanks for assistance everyone. Just to let you know, I think the problem has been solved.
I had a couple of new tyres fitted at the front for the MOT, which were the same size as the back two. Previously I had 215/80/15 at the front and 235/75/15 at the back.
I then decided to give it a try in FWD on some wet and slightly greasy roads and lo and behold, no nasty noises, drove perfectly. I presume if the problem was still there that it would have shown up in that distance.
So, if you get similar noises , bear the tyres in mind.

 

[Freebird]

http://www.commaoil.com/motorists

Put your reg and postcode in and it tells you what oil types you need and where to get them....:thumbs

Excellent link this, very useful..... :thumb2