Caliper - wheel clearance?

[DCMVan70]

Hi

I am fitting some 4 1/2" wheels to my van. The old wheels were 3" with 20 year old 165 tyres, so it was time.
One of the front wheels is touching (paint not metal) the caliper. I have Grumpy Marina hubs and new calipers from ESM (they are a newer type with the brake pipe connection on the top next to the bleed screw, not in the center). The other side is fine and I did not have any issues with the old 3" wheels.

What sort of clearance would you expect or is required between the wheel and the calipers?

I have measured everything and the issue seems to be that the caliper on that side is a little larger than the other (about 2mm) and the caliper is not quite sitting square/vertical. I am thinking I could shim the caliper to move it over a bit (just at the bottom), and/or I could just file off the offending corner of the caliper - there is a bump at that point. Any body think I am suggesting anything unsafe?

Regards
David

[philthehill]

David
I have 7J wheels fitted to my Grumpys / Marina brake kit and have no issues with clearances. The hubs are modified Marina not the later ESM type. The callipers are original Marina.
I have approx 2mm to 3mm difference between the outer face of the Marina hub and the outer extreme of the original Marina calliper.
If you could post a picture of the contact place between wheel and calliper - It would be good as then a better opinion can be formed and suitable advice given.
If you shim the calliper you need to do both bolts otherwise you will be throwing the calliper piston off alignment which could lead to calliper seal failure.
Phil

[DCMVan70]

Hi Phil

My hubs are the modified Marina hubs with the top hat spacer changing the PCD - just like a photo you have shared before of yours when I asked about a sheared wheel stud! I have about 2 or 3mm clearance on the other side which has the same calipers.

Here is the wheel with the marks

Caliper measurement

543ed73e5ca36006-photo.JPG (1.61 MiB) Viewed 861 times

This picture shows the caliper touch point

Caliper touch point

Caliper touch point.jpg (4.84 MiB) Viewed 861 times

This measurement is about 2mm wider on the side that touches compared to the side that does not, only at the bottom, I was thinking of just shaving a mm or two of the corner that touches

Wheel with marks

Caliper measurement.jpg (784.23 KiB) Viewed 861 times

With regards the shims, I see that there seems to be more space between the disk and the caliper at the bottom than at the top, hence the idea of shiming just the bottom, but I see what you mean about doing both equally.

Slightly off the original topic - but you may remember that when I broke a stud you recommended the correct replacement.
I have fitted four, but was just noticing that the shoulder is in a different place on the new one compared to the old ones - think this is related or an I over thinking things?

Originals studs

Original studs

Original studs.JPG (567.89 KiB) Viewed 861 times

New ones

New studs

New studs on problem side.JPG (659.1 KiB) Viewed 861 times

Regards
David

[philthehill]

The transverse position of the calliper in relation to the disc is set by the machined face for the mounting bracket on the swivel and the calliper location on the mounting bracket.
A photo of the actual mounting bracket where it fits onto the swivel would be helpful.
It may seem a silly question but did you install the wheel bearings the right way round on both sides and have you allowed too much play in the bearing? There should be just 3mm play (max) at tyre outer edge/circumference.
There should be sufficient clearance between wheel and calliper to allow for variances in calliper dimensions.
The outer extreme of my original Marina calliper is 63.5mm from the inner face of the disc.
My Marina calliper is of a similar outer profile but the bump indicated does not appear to be so large.
The outer edges of the bumps are 62.5mm apart - that is between the outer edges of the top and bottom bumps.
I would recommend not taking any metal off the calliper as I do not know how the fluid transfer galleries are placed.
As regards the wheel stud - not all Marina wheel studs are the same profile. So long as the stud is fully home then there should be no worries.
Phil

[DCMVan70]

Hi Phil

Here is a picture of the mounting...

Caliper mounting.jpg (585.04 KiB) Viewed 830 times

I hope I did not mess it up, as if you remember the calipers were on the front of the disc when I got the van! I found some Grumpy instructions and followed them when swapping over.

Only think I can think is that there is too much paint, but that would more the caliper outwards and closer to the wheel.

I am pretty sure that the bearing done up correctly, there was a little play, but very little. I tightened until I could feel the rotation slowing and then backed off a flat to get the split pin in. On this hub I did not remove the inner bearing when I took everything apart - it was held in place by a spacer - I think called a top hat spacer, so I did not remove it. Also if the hub got any closer to the vertical link, the caliper would get closer to the wheel?

This is a picture of the old and new calipers - the only thing I see is that the new caliper, measured from the mounting surface is 2mm wider at the point contacting the wheel. I am going to put the old one on and see if there is contact!

Two calipers.jpg (588.34 KiB) Viewed 830 times

Regards
David

PS, I did check it is not a bad wheel by swapping them over