Front swivel issues

[clover]

Hi

OK this is a slightly long explanation...

Whilst in France I had to drive about 30 miles with collapsed wheel bearings (long story - I won't bore you with the details other than to say read the details of your European break down cover if you have a vehicle modified for off road use).

We managed to fix the wheel bearings (Thanks to Chris B whose help was much appreciated). I was able to drive home without any further complications. HOWEVER...

After changing the bearings I noticed that I had a bad vibration through the vehicle at 55mph that I never had before the wheel bearings fell apart. It was notably worst when going uphill on a road with adverse camber (left sloping down to the right).

I thought it might be the diff as there is loads of backlash in it. Its definitely on its last legs. I decided to set about changing it and also to fit new stub axles as mine both got trashed when the inner races welded themselves to the stub axle. 

I had an unpleasant surprise when I removed one of the stub axles. The swivel housing has no grease in it to speak off and a quick inspection of the inside of the stub axle showed that the brass bush was absolutely trashed. Fortunately I've got spare stub axles and will also replace the CV to be on the safe side (belt and braces). I am however concerned about the top pinion bearing as I am assuming this will have also been ran dry. Thing is I can't actually feel any play in it and am wondering how I check properly. I have heard that sometimes these can have play in them that can be shimmed out as it can cause weird vibration???

Could use some advice as I've loaned out my workshop manual...

[Les Henson]

The top pinion bearing on a Disco is a taper roller bearing - the same as the bottom one. If the bearing was worn it would have play in it or you would feel roughness in it when you turn the hub from lock to lock. If you have the stub axle off at present - it's not more work to remove the swivel housing and check them visually.


Les.

[Eeyore]

Another way to check is to jack the front wheel up and grip both sides of the wheel. Give it a good tug and try to wobble it, as you would for checking the wheel bearings. Then repeat, but grabbing the wheel top and bottom. If you get movement top and bottom, and not side to side, then that'll be your swivel bearings requiring attention. If you only get movement side to side and top and bottom, check your wheel bearings again.

Its worth doing the same check once the any problem with the relevent bearing has been addresssed, you know, just to make sure like.

If there's play in the swivel bearing, this may be addressed by reducing the shim pack for the top bearing. These are found under the top-pin flange - the two bolts on top of the swivel, where the brake pipe mounting is found. Again, jack the wheel, whip them bolts out, ift out the swivel pin and hopefully there will be a few thin shims underneath it. Remove one, refit and check for play. If there's still play, try removing them successively. If you've removed 'em all and there's still play, the bearings will need replacing.

.....thats a slightly longer job, but surprisingly not too difficult. Annoying yes, but not difficult.

Hope some of thats useful!

[clover]

Cheers...

I did have noticeable play top and bottom in the wheel on the side that ran dry of lubrication when I checked before I took it apart.

OK so now my next question...

If put in new swivel pins, bearings and oil seals do I just fit them without shims and see if there is any play and add shims until no more play or should I not need shims with new bearings etc???

[Skibum346]

Can't be certain but I think the shims are related to the ease of pull of the swivel. You need to adjust shims to get the right pull using a spring balance (fishing scales will do). I can't remember the figure or the process, but I'm sure more informed peeps are just around the corner!

Skibum
 

[andyb]

If put in new swivel pins, bearings and oil seals do I just fit them without shims and see if there is any play and add shims until no more play or should I not need shims with new bearings etc???

New swivel bearings will require more shims.

You will need to have the steering arms detached from the swivel and test the pull resistance with a 'spring balance'....bascially what fishermen use to hang fish on to weight them. Put the spring balance hook into the hole for the track rod end and pull on the other end (probably have a ring you can get a couple of fingers thru)

With the big oil seal in place around the swivel you should see 12lb of pull just before the swivel starts to move. Without the seal in place it is 4lb of pull just before the swivel starts to move. Makes sure that the bolts holding the pins into the swivel bearings are correctly torqued down before testing the resistance.

It is also worth starting with more shims than you think you will need or you might damage the swivel bearings themselves if the pins are too tight.

Hope all that makes sense :)

[Les Henson]

I always put the old shims back on and then adjust it from there. Whenever I rebuild a swivel housing I always set the preload a bit too high. This is because it eases off once the new parts have bedded in.

Rebuilding a Disco front hub -

http://forums.lr4x4.com/index.php?showtopic=5601


Les.