hub inbalance

[phil clark]

Hi, has anyone ever experienced front hub inbalance after a wheel bearing change on there 306?, Had both front bearings changed for its MOT, and since the front discs have had quite a major inbalance, causing the brakes to squeak. Ive changed the discs today in an attempt to try and cure it, thinking they may of been warped due to the heat caused by the wheel bearings formally being shot, but theres still a distinct wobble. Any ideas guys?. Thanks

[pug306driver]

since the disc's are held on by 2 screws, the front can be raised and the hubs/discs watched for warpage etc by running the car in gear..........how are the wheels ( same method but with wheels on and tieght.....).

make sure the car is safe to do this , before you do it.........

[cully]

maybe they/you bent the hub centre pressing it into the bearing

[Poodle]

What makes you think they're wobbling, is it just the squeaking? Does the squeaking happen all the time or just when braking or just when pulling away?

[phil clark]

Three great reply's guys. Going to try and cover a reply to all 3. Ive had the car up on stands, wheels off, and run the transmission engaged in second and watched the inbalance. Both discs on one full rotation go from touching the inner pad (leaving a gap to the outer pad) through 180 degrees to touching the outer pad (leaving a gap then to the inner. This was observed with the caliper folded up. Its visible also using the disc cut out in the pad carrier. Now ive changed the discs, and its still running untrue. I stripped the hubs off my self, but had the bearings switched by my MOT mechanic, using a press at the garage. This is on BOTH front wheels. He had to use a little heat to remove the old circlips, as they were rusted in. When a drive shaft passes through a hub, which part or how is the bearing kept central by tightening up the nut?. Thanks :-)

[Poodle]

Ok so it's clearly visible then, weird that it's the same both sides, makes accidental damage unlikely as a cause... I wonder if your mot mechanic has burred something slightly when pressing the bearings, probably worth having a look at the hub face - both for any marks and check them for run-out the same way you did with the discs, use a mounted dial gauge if you can. If you get that far have a look at the back too, the bearing should be firmly seated up against the circlip, although you won't see anything useful with the driveshafts in.

The bearing is kept central on the shaft by design, tolerances are tight enough that it shouldn't press in wonky, if ti's not true it gets stuck after a few mm. Unless they're REALLY cheap lol. Circlips always rust in, that's nothing unusual.

[pug306driver]

are you sure that the discs seat on the hubs properly......do as suggested with a dti ( clock gauge ) on the hub faces.......

[phil clark]

Right, dial gauge it is, BUT tbh im certain just via the naked eye and tip ex line that ive added to the hubs I can see a distinct run out pattern. One thing I must add, that ive remembered from me rebuilding it, I did torx up the 35mm nut on both sides, while it was on the floor, having only nipped the nut up with a rachet, and im wondering if the weight of the car has inbalanced the initial torx up procedure. *HANDS UP* im old school lol, and its how we use to do them, and as in my stupidity I didn't fully read Haynes, which clearly states while off the ground, brakes firmly applied, im wondering if the cars weight has splayed them and caused this. 3 days off over the weekend, so its dirty hands time, and a look round the back of them bearings. Thanks guys!!!!!! :-). Ohh, one thing to add, the driveshafts do move in and out as needed with ease, as I cleaned them well. Should I use grease to try and remove any possible slight over tolerance?. :-)

[Poodle]

That could well have done it, bearings don't like being loaded without being tied together first lol. You're probably thinking of doing up the old cone style bearings, they don't even need nipping up.

If you've already checked the hub faces with the disc off and there's a clear imbalance, then it's definitely a bigger issue than just poorly seated discs.

[Paul_13]

What brand bearings did you use? Please don't say vtech. They shouldn't be allowed to sell them they're down right dangerous

[phil clark]

Sorry about the delay guys, work came calling. I used Berax Bearings, and tbh they did look the part quality wise but as we all know that means nothing as you cannot see whats going on inside. Can recall using them before, but I forget in which application humm. Anyway, all being well, i'll have a dam good look over the weekend and report back. Love this new set up and colour scheme :-) :-) thx

[Piggy]

I would be inclined to check those hub nuts...

How tight did you do them??

[phil clark]

They were initially torxed up to 210nm, then taken up to 310nm, but ive backed them off to 200 so I have a little room for manipulation of the bearing (if it is possible lol). Ive read up on how these things work and so far concluded that the grease plays a massive part in how square and true sealed bearings run.
When torxed up flush, the grease moves inside the bearing housing to all the internal parts in varying amounts place by place, to keep everything balanced, and as im now certain I mucked up, and set them at an angle, im wondering if theres a way of reversing what ive done lol. How I understand it, its not just mechanical wear that makes them go bad in the first place, but also the fact that over time the grease breaks down by water and dirt getting past the rubbers seals, which creates a knock on effect of misalignment then mechanical wear. Just got to figure out a way of Rebalancing them lol :-)

[phil clark]

Well, its all been stripped down again today, cleaned and lined up flush and the problem's still there. Done a couple of videos which ive posted to youtube, so you guys can have giggle at the modern day whacky Races!!!. Enjoy!!. All torxed to 320nm this time too :-)

https://www.youtube.com/watch?v=Sura2CnRUqs

https://www.youtube.com/watch?v=3gjvBaQ7US4

[Poodle]

I'd say that's the bearing, as the driveshaft is wobbling too by the looks of that second vid.

[phil clark]

I think id be inclined to agree with you poodle. Its the same both sides. Theres no play in them at all, But its as if they've both been pressed incorrectly, or the quality of bearings I provided wasn't up to much. Does anyone know any good brands they've used?. I was considering Timken, but @ £50 a side its an expensive gamble. What about Quinton Hazel???. Thankyou :-)

[madmadmax]

skf, timken,orbis,f.a.g and snr are all good brands if you have the old berings ther will be a code on them that denotes the dimentions and ball to race clerance that you could googel to see if theres a cheper supplier out there

thers this is where i get most of the berings never used ther kit befor http://simplybearings.co.uk/shop/Bearing..._info.html

the code willhave 6 digets of numbers and letters so 62052z then it may have a two digest a number and the letter c like c3

so it may look like 62052z c3