I recently converted my P400 from 20 to 18" rims and noticed after some trips in the mud that I'm seeing some small grooves on all 4 rims. Very shallow. I expected some given the tight clearance and muddy terrain that I've been planning on visiting. Front right where no brake mods other than removal of the mud-scraper was done has the worst damage. I want to say ~0.5mm deep by 2mm grove has been carved by a rock between the front caliper and the rim.

I knew this was a risk factor associated with the change to a smaller rim but had figured it would be the rears where the clearance is tighter, 2-3mm following the caliper trim, versus the front where there is a more normal ~5mm I guess.

It would seem, a smaller gap prevents bigger pebbles getting lodged.

I don't think the groove is deep enough to compromise the integrity of the rim but wondered if others, having done a similar mod to their P400/D300 had noticed anything similar on their rims.

What is the thickness of an alloy rim in that internal area? anyone know? I've been googling to no avail. I know it will vary from rim to rim of course but figured there was a typical range. I'll touch base with Tuffant and see if they have the specs. I'm hoping there is some 4-5mm of Aluminum there.

 

I have a P400 with stock 19" rims and the same thing happened on both the rear rims though not quite to 0.5mm. I seem to remember reading a couple of cases where a rim was destroyed before the rock or pebble freed itself.

 

Yes I saw something like that on FB where they were on an long trip in Australia and a rim split. Another user on here had it happen to them.

The tolerances on the 19"rims is very close on the rear calipers also.

I was just wondering if this is a normal consequence of muddy off-roading fun. Some grooving of the rims.

Thanks very much for chiming in with your own experience. I guess my thread title is a little too specific. Hadn't thought of the 19"s

 

Haven't looked at the exact clearances of a P400 with 18's. Curious if you could fabricate something akin to the wheel scrapers used on rally cars. Metal mount with replaceable silicon or plastic material the remove snow/mud/etc.

Of course, if the wheels are simply too close to the caliper (after grinding or replacing with the smaller caliper), that's a different story...

 

They're close. Real close.

OEM on 20"s comes with a mud scraper on the fronts. This scraper is not on the OEM 19" setup. Its removed to fit 19's or 18's. It's a close fit with 18"s.

Curious if other members of the "P400 rollin' on 18"s club" have noticed anything similar on their rims.

As I said. I was watching the rears closely. Turns out the fronts are the ones taking more of a pounding.

Switching back to my 20s for my winter rubber soon. I'll snag some pictures of the damage then.

 

you think JLR has put the mud scrapers back in the 19"s? It sounds like they only removed it to make some more room, but if it's causing a problem with the rim maybe in later years they added that back?

 

No Cry, offroading Hurts..
Even my 18" with small calipers are scratchd it's not only Mud often some stones in it.

Mall Crawlers are unfamiliar with this.

 

No
19s would not fit with the scraper in place.

 

Just parked next to a Ford Expedition with 275/65/18s... how does a truck the size of a 130 Defender fit an 18" rim and not a 110? I think JLR has some pathological level delusion that only big rim Defenders are desirable or something. I'll convert my 19"s if it is a problem... but I'll give it a go for a while first.

 

Gavin, I just checked all 5 of my 18s (I have the 20s on the Defender now and the 18s in the garage), not a sign of even a scratch, let alone a gouge like you have. Mine are OEM steelies, though, so far from an apples to apples comparison. Also, I don't do much mud/snow/slush work compared to you; more dry rock and gravel and dirt/clay. But I do wind up in the muck from time to time.