Hi all,

I've seen multiple posts of folks "adjusting" or shaving down their rear brake calipers 0.25 of an inch to fit 18" on the P400. When searching online, there's a lot of "don't do this!" but with no real specifics on why. I've talked to a Porsche enthusiast who stated this is a common practice among Porsche owners to get the right adjustments and tires to fit, and wouldn't give it a second thought. Their cars, of course, are driven at higher speeds with more heat than a regular Defender trip.

So my question is, does anyone actually know what would fail or the actual risk? I've heard thoughts around:

1. It might reduce cooling of the caliper although very minimally 1-2% for the amount of material taken off.
2. Those could be for reducing brake dust
3. It could crack the brake caliper (seems unlikely)
4. Something else???

I would be curious to hear others who have made this adjustments. Any issues?

Note: Not my images, I found these online.

 

Those ribs are (In my opinion) designed to clear the 19" wheel of debris. The hand was made to fit the useless glove.

The caliper was enlarged to fit the 19" rim for reasons only LR can fathom. There is a perfectly usable LR caliper that fits with many 18" rims (not the OEM steelies) already in their parts bin. Disco5 and some other models use it.

I trimmed mine 40,000 miles ago. So far so good.




Lots of images on this in the two big threads on the topic.