diagnosing front axle noise

[Christoff]

i had a noise from the front axle so iv got it in at work to look at

Found side to side play in OSF wheel and also top and bottom play

Found top and bottom play in NSF wheel

Play is still there with brake pedal pressed which i assume to cancel out bearing issues

The play seems to be coming from the swivel hub assembly

what needs to be done and is ths urgent?

ta

[Christoff]

iv decided its probably a combination on a number of faults and wear

on further inspection the noises seem to be transmission related

1. input shaft noise/ backlash in transmission

there seems to be clunking as the clutch is engaged. This noise is also heard while driving slow in 1st or 2nd gear under light or no throttle

2. worn prop UJ's

theres a vibration through the chassis when in too high gear for vehicle speed, i.e. 3rd gear while moving out of a junction. The transmission backlash / input shaft wear would also probably contribute to this

3. the play in front wheels would probably require me to strip down the front axle and find the wear. I woud possibly need to replace it if i find worn swivel hubs for example.

does all this sound correct ? Scotty? lol

[andyrew]

Sounds like the kingpin bearings are tired. You can remove a shim from them and take up the play. If no shims are found then it's time for a new bearings. Wheel bearing may just need sniping up and some fresh grease.

[Christoff]

Iv already done that to the wheel bearings. Unless for some reason they have come loose. But I put a castellated nut on and bent it over as standard so it shouldn't

If I was to remove a shim on the kingpin bearings, would it not be better to just renew the bearing to save having to do it all again ? Iv never done it so not sure what to expect.

[ScottieJ]

The play does sound like kingpins, if you wobble the wheel but stick your head round to look at the knuckle seal you'll see it moving on the ball, I usually just whip a shim out at a time until the play has gone but keep the shims for when you get new ones, doing this gives you a quite a bit of extra life out of them as they wear, sometimes the bottom one gets a bit dry though so might be worth inspecting and adding some grease in the bearing.

Have you got freewheeling hubs? Normally any front transmission problems are only noticeable in 4wd if so as none of it will be spinning in 2wd apart from the wheel bearings.

[Christoff]

Yeah mainly 4wd. Iv only noticed a problem since iv had it in the air and physically felt the play

And yes I can see the swivels moving on the hubs.

How big a job is it to remove a shim and regrease?

[ScottieJ]

Removing shims is literally jack up and remove the 4 bolts holding the kingpin in and pull it out, re-greasing requires the knuckle to be removed.

You're not using 4wd on road are you? This is something that should never be done as it causes transmission wind up. 4wd should only ever be used on loose and slippery surfaces.

I'm sure you'll already know that but have to check.

As for the vibes pulling away in high gears that is perfectly normal because of the divorced transfer box. The torque will be putting a lot of strain on the rubber bushes and allow it to move around more than it normally would pulling away in a lower gear

Remember as well there will be a lot more backlash in the whole transmission than on a normal car because you've got the combined amount from the gearbox, tbox and diffs, small clunks are pretty normal. As long as there's minimal play in UJs the tbox outputs etc I wouldn't worry too much

[Christoff]

Oh that sounds ok then and yes I know about transmission wind up

There is play in the props but I suppose its minimal and iv lived with it for 2 years. Although it might be getting progressively worse.

Il leave that to develop a little longer then and concentrate on the kingpins. Is it possible that the wear will be on the steering knuckle ball joint and not in the bearings? Because this would require a new axle wouldn't it ?

[Darrell]

The axle should be fine the weight is on the kingpin bearings. If you play in deep water it gets into the swivel housing and then ruins the lower bearing.
Here is a good write up done by Martin from big Jimny, a few slight differences to the SJ but basically the same.
http://www.bigjimny.com/images/document ... arings.pdf

I seem to remember on some axles you can get away with leaving the wheel bearing alone and just undo the spindle ???? watch this space !!

[Darrell]

Found another and it seems if you remove the disc you can get to the bolts and then remove the spindle complete with hub and bearings.

http://forum.difflock.com/viewtopic.php ... t=king+pin