Wheel / DeDion Clearance

[AlastairA]

I was out for a blat at the weekend and in slow moving traffic noticed a squeak coming from the rear nearside axle. It seemed to be periodic consistent with a wheel rotation, so when I got home I removed the wheel for an inspection.

I found the inside surface of the wheel had a witness mark that was at a position equal to the outside edge of the DeDion:

The end of the DeDion was also marked:

With the wheel refitted I checked the clearance between the DeDion edge (where the mark is) and the inside surface of the wheel and estimate it to be around 1.5mm to 2mm - so the abrasion is not from constant contact caused by a tolerance issue. I'm struggling to understand how this might have been caused.

Any ideas - anyone else experienced similar?

[ECR]

Can't tell exactly where the touching occurs but on my 1990 chassis I found it necessary to take an angle grinder to the dedion end plate to give clearance on the wheels that I fitted

[Drumster]

Common problem it seems especially with 8" rears. I reckon you've been unlucky in that although the de dion isn't actually touching the wheel you may have had a small stone get stuck between the de dion and the inside of the wheel. What ECR has mentioned above is the way forward.

It happened to me recently and I have a gap of at least 3-4 mm.

[Drakman]

I would be checking your wheel bearings.  If you have 1.5 to 2 mm clearance something is allowing the wheel to move to take up the 1.5 - 2 mm gap.  I recently fitted 8 " rears to mine and it has similar clearance to yours but no rubbing.

I don't think a stone would mark the steel De Dion tube like that without making a serious mess of the rim.

Another consideration with 8" rears is, make sure you tell anyone balancing the wheels not to place stick on wheel weights on the first 2 " of that area of the rim.

Cheers

[ChrisC]

Your see that on every modern dedion setup with 13 x 8 rear wheels.   I believe it's stones, if you had massive play in the wheel bearing there would also be evidence on the disc / caliper.  Also wheel bearing play would not pass IVA, I am assuming your car is relatively modern because the dedion face is clean. 

[AlastairA]

Thanks all - very helpful.

I spent this morning taking a good look at everything again - no wheel bearing play - a 2mm gap between the wheel and DeDion, so I think the scuff marks on the wheel and DD are indeed just from road debris occasionally getting trapped in this bottleneck.

However - on a test drive this morning the squeak is still there. Actually it's more of a rubbing noise consistent with every wheel rotation and seems to disappear when I apply the brakes. I checked both the rear discs and there is even wear on both sides of both discs so i don't think its a stuck piston. The only witness mark I could find was on the reluctor ring, so I backed off the speed sensor a minute amount. Another test drive and the noise was still there but it seemed to be slightly less. 

Any comments greatly appreciated!

[Dixa1225]

Check there is no up/down movement with the brake pads in the carrier. The springs on the pads can be adjusted to stop any rattling.   

[Tiddy7]

Also always be careful with wheel balancing weights as they can often hit the dedion, I would suggest grinding off the suspect area to gain at least 5mm clearance as the whole tube hub/ wheel can deflect a considerable amount under load. There is no issues with the structural integrity of the de-deion tube in this area, (its quite likely to fail elsewhere, just not here!)

[ECR]

Put some masking tape on your wheel over the scuff mark and drive again. View the tape after the drive

[AlastairA]

Thanks for the comments - will double check all those points and try the masking tape idea.

Appreciate your help.

[Geoff Brown]

TADS sir ! Especially with 8" wheels. It is just grit getting caught between the de Dion & the wheel.

I removed a small amount of material from the offending part of the ear but there is only so much one can remove before endangering the land of the weld.

So, have put up with the marks for some ten years.

 

[AlastairA]

Just to close this out - I cleaned and cleared the gap between the wheel and DeDion, but the squeak persisted.

I couldn't help but focus on the fact that said squeak seemed to disappear when I applied brake pressure. Today I disassembled the nearside rear brake to inspect - the only oddity that I noticed was the stainless steel spring plate that sits under the caliper and above the pads was loose (one end was not under the caliper and would not stay in position when I put it back).

I reassembled and in the process tweaked the springs on top of the pads a little higher, reapplied CopperSlip to the edges of the pads, and then bent the end of the stainless spring so that located correctly in the caliper housing.

Not sure which of the above did the trick - but no more squeak! Trivial issue, but I find it really difficult to put up with things that aren't quite right - especially squeaks!! 

Thanks all for the helpful comments.