Brake discs too big?

**hifihedgehog** · 23-03-11, 06:52 PM

Hi,

Just started putting the brake discs/calipers on my dd rolling chassis ahead of putting the brake lines in and I've noticed something thats not quite right.

Obviously the solution to this problem is "ring dax" but just thought I'd share this incase I'm going mad.

Pics attached below are of front hub/caliper carrier thingy.

IMG_0716.JPG IMG_0719.JPG IMG_0711.JPG

When I was arranging delivery of the chassis I was told that there happened to be some bigger sportier brakes available if I wanted them so naturally said yes as clearly to the newbie that I am "sports upgrade" means "better". Using a tape measure and mk1 eyball the discs appear to be 328mm dia. I dont know much about the original jag upgrade options, did the bigger brakes have different mountings for the caliper so it sits further out?

This is the first bit of the car I've assembled that isnt explained in detail in the dax manual, it says refer to the xj40 workshop manual, which I guess is different to a Haynes manual, I spent quite a while trying it all different ways round in case I was being a complete spanner but it just doesnt fit!

Please ignore terrible and unneccessary painting of parts, (not that you can tell from the rubbish camera on my phone) I had some black hammerite and a spare weekend with nothing better to do but never actually finished them properly.

Dave A

**Clarkson** · 23-03-11, 07:57 PM

There should be an alloy adaptor bracket for that.

**hifihedgehog** · 23-03-11, 08:45 PM

Originally Posted by Clarkson

There should be an alloy adaptor bracket for that.

Aha! Excellent, thanks

**Mike Read** · 27-03-11, 10:38 PM

Dave,

I bought a rolling chassis from DJS with standard discs and decided to upgrade them to the larger discs later ... if you have a set of donor jag wheels you will find they don't fit with the bigger discs on. Also, I had trouble with the larger diameter front discs touching the top and bottom of the calipers and had to grind the calipers out slightly to get clearance. You will know if that is happening as the front wheels will either not turn or there will be a horrible grinding noise when you spin them by hand!

If you bought the upgraded discs with the hubs, DJS will have modified the edges of the hubs so that the front disc bells fit over them properly ... buying the upgrade later, I had to modify the edges myself to get the discs to sit squarely on the hubs.

Regards, Mike

**hifihedgehog** · 28-03-11, 12:26 PM

I bought it all with the upgrade from the start so hopefully its all modified. Thanks for the tip on the wheels I didnt know that, I'll have to leave the discs off so I can still roll it around until I get some proper wheels. Ive found the adaptor bracket which was hiding in the bottom of a box of other bits. One set of holes as an enormous countersink in it so I guess its mean to fit one way round but not really sure which way this is.

Ive bought everything from dax so having not stripped a donor I'm slightly lacking in knowing what it should all look and be like when it goes together. I managed to get hold of an x300 workshop manual in pdf which I guess is pretty similar to xj40 for the greasy bits, it has shed light on some parts of the dax manual that are "economical" with the description but its still a struggle. All part of the fun!

**Mike Read** · 28-03-11, 01:42 PM

You should have some large allen key headed bolts which fit the counter sunk holes on the adaptor plates. They have to be flush so that the caliper carriers can sit flat against them.

Regards, Mike

**hifihedgehog** · 28-03-11, 03:15 PM

Mike,

Just had a look through the fixings supplied and cant find anythign that obviously fits, the remaining bolts in the "front suspension" bag are all way too long or far too shot. All the dax guys are tied up at the mo ill try ringing them tomorrow to see what help they can offer. Left it a bit late to actually finish the rolling chassis, body is coming tomorrow afternoon! eek!