Rear Wheel Bearing/Seal Arrangement

[Jon]

Hi,

Has anyone got a good sketch of the wheel bearing and dust seal arrangement for the rear of an S1 montecarlo.

As far as I can see there should only be one steel dust seal behind the bearing, as in the schematic in the parts manual. But from infomation from other sources it would suggest one infront of the bearing too, or is this S2.

Can anyone help with this?

Thanks

Jon

[Wallace]

There's two. Definetly. Series 1 or 2 - both the same (and X1/9 for that matter (but with different drive flange).

Standard parts - I got mine from the local bearing shop.

[Jon]

Hi Wallace,

Can we be perfectly clear here, I mean the pressed steel ring not the rubber wipers?

Jon

[Wallace]

In that case - NO !!!

There are TWO rubber seals (front and back) but only ONE pressed metal seal which goes on the back (or drive shaft end) of the hub.

The front end (or wheel side) has threaded locking ring which persumably seals the bearing a bit - BUT - it's mostly there to hold the bearing in !!!

The rear pressed in one can stay put if replacing the bearing - if it does get a bit mangled it's thin enough to be flattened with a hammer ! Might need a dribble of locktite to hold it in place though. Not aware of replacement parts available - Chad does the locking rings or try an x1/9 specialist.

[Jon]

Wallace,

Thanks I did think that was the case it brings a lot of confidence having a second opinion.

Didnt want to go to all that work to find out later that I was a compenent short.

Thanks again

Jon

[Will]

I have a spare set of the special tools to remove the bearing rings. $50 for the set, or $10 to rent (+ shipping).
-Will

[Wallace]

ah .. the locking ring - and how to remove them .. .

I welded up a lump of bar to the insides of them - gripped said bar in a vice and thumped the hub in an anti-clockwise direstion until they came off !

Possible to cut/weld fabricate a spanner to do them up (or borrow Will's !!!) - but becasue they've been locked in with a crimp on the threads (plus rust /dirt etc) it's unlikely the "propper"way with fabricated spanner will undo them ! Will's probably would - but it's a long,way away .. .

I came over a bit daft in the end and made up two new ones out of stainless steel with 6 holes bored into them to take a 6 pegged spanner. (which I also made)

Bearing removal is best done with a puller/press. But I once replaced the front set using a LARGE vice ! Depends how desperate you are !!!

[Jon]

Will,

Thanks for the offer.

The old ring nut came out easy on both rears with a hammer and a chisel. As I run a machine shop I made a stainless steel ring nut spanner with four dowels that fit the new ring nuts and have a hexagon drive so I can use a torque wrench to get the ring nut just right.

While on the subject of the rear bearings, is it advisable to lightly grease the rubber wiper seals?

Regards

Jon

[Wallace]

Can't hurt can it ?? - for as long as it lasts !!!

[Jon]

Wallace can you help?

As you know a couple of weeks ago I fitted a new rear wheel bearing, however upon completion I found there was still play in the hub. My only explanation was that perhaps I had not pushed the bearing home fully as I had not used a press, instead I used Large Nuts and studding.

So I again removed the hub arrangement and the bearing, destroying it in the process, and proceeded to fit another new bearing. This time I had the bearing pushed all the way home with a press. I only pushed the outer race when fitting the shell and only the inner race when fitting the hub. I torqued the nut up as per manual and to my complete frustration it still has play. I even tried overtightening the nut, this did nothing but eventually stripped the nut.

Has anyone got any ideas? I did think perhaps the splined shaft was too long and bottoming out but I checked this and its fine.

Or maybe I am being too fussy? There is about 0.1mm (0.004”) FSD Axial Movement at the outside of the brake disc.

Regards


Jon

[Wallace]

Hmm. No idea - I don't know what the run-out should be - I'll have a look in the manual - but 4 thou at the edge of the disc is not a great deal at the center. how did you push the hub and bearing in ??
The bearing should be pushed using a sleave that contacts only with the outer shell of the bearing - likewise when pushing the hub in, the inner sleave should be supported from behind with a suitable piece of metal.
Otherwise you're transmitting all the "pushing" force through the actaul bearing surfaces themsleves which could lead to possible dammage. Although they miust be pretty heavy duty - think of the force on them if you hit a pothole at speed.. . .,

Just read you post again and you did all those things so it cant be that .. . !

The bearing itself is not the type that can be tightened up - it's a ball as opposed to a roller race.

I suppose if you take 1 thou runout as as a running clearance then if the discs are roughly 4 times the diameter of the bearing, then 4 thou is about right for the disc edge .. . it does seem a smidge excessive though .. . I'll have a look at mine.

[Jon]

Thanks for that Wallace,

Yes I know 0.1mm isnt much but it feels worse. It feels quite a lot by the time the road wheels are on.

Jon

[Wallace]

Looked at the manual over the weekend - run-out for the disc is 0.2mm. But that's "rotating" type run-out, not "give it a bloody hard yank" type .. .

I suppose jack it up and see how it compares to the front wheels .. .

[Jon]

Wallace,

Thanks for looking into this for me, Im afraid I also came up with the same lack of infomation from the manuals.

I originally changed the bearings because the handling was terrible and the back end tried to spin me around a small roundabout. After checking play everywhere in the rear I found a lot of play in the left hand rear bearing. I changed the right as well as a matter of course but I believe it was tighter before I changed it.

Any way I hav'nt tried the car up untill now as I was waiting for some new anti roll bar bushes to be poured in the mold I made, but I have been convinced that I can drive the car without the anti roll bar.

Yeah ok I did change the lower ball joints, the wishbone bushes for poly and grit blast and powder coat the whole rear suspesnsion assembly (Not springs or shocks) but the car is now heaps better as a combination of all the new parts.

I also recieved an email from a scorpion owner who experienced the same on the rears but the fronts remained tight after changing all four. So I have decided I have done all I can, the play must be in the bearing itself, and im going to run it for a while and see how it goes.

I had a word with Chad about it, and he suggested that maybe the hub is clamping up on the drive shaft boss rather that the inner race of the bearing, but I chaecked this and I am sure there is about 1-2mm of clearance to prevent this happening. So even if you had a skinny bearing it would still be clamped.

Thanks again and sorry this is a bit long.

Jon

[Ken H]

Jon,

In my experience, there is usually some perceptible play after installing new wheel bearings. The amount of play seems to be a function of the tolerances used in the bearing manufacture, and varies between bearings (possibly manufacturers although I haven't checked this). As you know, there is no adjustment for this. Some small amount of internal clearance is designed in and is necessary to prevent stress failure of the bearing.

I've seen no handling quirks as a result even though one tech inspector threatened to flunk me until I convinced him that there was no adjustment. You'd certainly experience nothing of the magnitude that would cause an unexpected spin.

If it really bothers you, you could try switching to a different brand of bearing.

- Ken

[Will]

Have you ever found a "good" bearing other than Steyr/SKF ones?
Those are what I always try to get for everything- I've found transmissions shops are the best bet for procuring bearings and seals.
-Will

[Wallace]

Silly question - but I suppose you did remember to put back in the thick washer that goes between the locking nut and the drive flange ???

[Jon]

Yeah I thought of that one too. definately in.

As both sides are the same Im putting it down too the bearing itself like will says.

The proof will be Wednesday on the track at Curborough.

Jon

[Jon]

Scratch the previous reply!

Not entirely happy with the handling now I have had chance to try it. Wallace will you take a look at my latest posting titled handling and tracking please.