Clunk from rear axle

5 replies [Last post]
Colin
Colin's picture
Offline
Joined: 11.10.2004
Location: Tarland, Aberdeenshire
GWOA Groups: Members

I have a 1988 LWB 300GD I am getting a clunk from the rear axle and when I jacked it up and took the wheel off, I can move the hub in and out  but there is a definite stop with a clunk when moving it in or out . on the same N/S Rear wheel my son noticed on one occasion, that when I had engaged rear diff lock in a muddy field, that wheel wasn't turning.  It cleared itself and turned when I reversed a short distance. I don't know if this is associated but when I engage 4 wheel drive I have to reverse when I reach hard ground and disengage 4 wheel drive or I get wind up? This happens even in high ratio and without engaging diff locks? Are these separate issues or could they associated? the car seems to drive well enough otherwise. Any suggestions would be greatly appreciated

Pistonhead
Pistonhead's picture
Offline
Joined: 16.12.2006
Location: Loughborough
GWOA Groups: Committee, Members
Re: Clunk from rear axle

Dealing with this enquiry to my mind can be done in small chunks as my little brain can't handle big questions. 

Working backwards is easier for me.  "when I engage 4 wheel drive I have to reverse when I reach hard ground and disengage 4 wheel drive or I get wind up? This happens even in high ratio and without engaging diff locks?" 

High and low ratio (H/L) should only be used when traversing loose ground. Dried and hardened ground is not for high/Low ratio selection. One needs to have loose surface where a wheel is likely to slip or skid to justify H/L gear selection. Using other than loose ground will instill transmission wind up and as you have experienced this condition the way out of it is reversing to unwind. Additionally, should the tyre sizes front and rear be different overall diameters then transmission wind up will be accelerated (that is having brand new threads on one axle and worn threads on the other axle will induce transmission wind up. 

"my son noticed on one occasion, that when I had engaged rear diff lock in a muddy field, that wheel wasn't turning.  It cleared itself and turned when I reversed a short distance".

Engaging diff. locks does not mean immediate locking; you need to be traveling at walking pace for the gears to merge and lock or be turning on the move. I forget the colour scheme of the locking diffs now which I believe are amber and possibly red.

Selecting diff lock should show amber light indicating selection has been made. When the diff has locked then the light should show red. Until this change, diff is not locked up. So in my opinion, what your  son witnessed was the wheel not turning as the diff lock may have not locked in until you reversed.

"I am getting a clunk from the rear axle and when I jacked it up and took the wheel off, I can move the hub in and out  but there is a definite stop with a clunk when moving it in or out"  

There is some ambiguity in your statement for me. When do hear clonking? Driving, on bumps, moving front to rear and vice-a versa, all the time?

How much of axial travel do get on the drive shaft?

Initially my mind is thinking rear bearing wear but you do not complain of bearing noise. Other measures which you could conduct is with the axle on stands and the wheel on, check up and down movement on the wheel that is on the 12 o'clock and 6 o'clock axis.

 

Arnie
Arnie's picture
Offline
Joined: 12.04.2004
Location: London
GWOA Groups: Members
Re: Clunk from rear axle

 "when I engage 4 wheel drive I have to reverse when I reach hard ground and disengage 4 wheel drive or I get wind up? This happens even in high ratio and without engaging diff locks?" 

 

The W460 does not have a centre differential to cope with 4-wheel drive on hard-solid road surfaces. Therefore you will get some wind-up. 4WD should only be used on loose surfaces.

g wagon g
g wagon g's picture
Offline
Joined: 21.04.2014
Location: uk
GWOA Groups: Members
Re: Clunk from rear axle

Hi

The diff locks work as people say

If you drive straight they take a while to click in as the wheels are moving at the same speed. The minute you turn one wheel will travel further than the other so diffs should lock in pretty quick

Any play up or down with wheel on or just in and out from axle casing

If you remove shaft from axle casing and check bearing. I have seen lock nuts come undone that holds bearing in position

My 463 has nuts to keep bearing secure and one is left hand thread which i think is the nearside from memory

I dont know if 460 axles are the same but i am sure it will be

Check nuts are not loose. Upon axle shaft removal it will be obvious what i am on about

Pretty much a diy job and easy

Remove wheel and brake drum, brake shoes and possibly handbrake cable guide and cable

Undo the nuts holding shaft bearing plate to axle, Think 4 of them

Pull out shaft if it will come out

If not there are a few options depending how tight bearing is in housing

1 prefered is a slide hammer

2 if you are careful is bolt drum on back to front and tap it with a plastic or wooden mallet. This i would not do but the drums are thick and unless you had to sledge hammer it out it should be fine

Best option is a cheap slide hammer from machine mart that will be cheap. Bolt it to axle shaft and a few hits and it will be out

Some people say to remove diff lock actuator but i never do as the diff lock collar is in there anyway

Refit but the shaft takes a bit of twisting to first pass through diff locking collar spline and then into diff. It either goes in well or takes a bit of rocking the axle shaft to get it home

The bearing will just start to fit in axle housing if all is well

If it does not at all costs dont get hitting it in. To get it to the point where bearing is in housing then a gentle tap is fine until it seats

Sounds a lot but its simple with care

Re assemble brakes etc and it is good to go

So check nut and decide if bearing needs replacing. I would replace unless its recently had one or is a real low miler

If the nut was lose i would replace as bearing has had some bashing. If it has been done ask why they did not tighten nut if it was lose

If its none of the above let us know as without seeing the car i am only going off past experience

                                          G

Colin
Colin's picture
Offline
Joined: 11.10.2004
Location: Tarland, Aberdeenshire
GWOA Groups: Members
Re: Clunk from rear axle

Thanks for your thoughts gents, I think it may simply be due to knackered shockers and a broken spring.

g wagon g
g wagon g's picture
Offline
Joined: 21.04.2014
Location: uk
GWOA Groups: Members
Re: Clunk from rear axle

If you can move the hub in and out it wont be the spring or shocks

They are not related to holding the axle shaft in to axle