Hello all, i'm Richard and building a sylva J15.

Could anybody confirm what the thread size/type is in the Sierra xr4x4 rear caliper? I thought it was M10 but after a couple of turns it locks up so better to ask before trying to force it.

I would Ask Jeremy but he is on holiday at moment.

Could it be 3/8" UNF ?

[Edited on 10/8/10 by monkeyarms]

I can't help on your questions but welcome to the site and please sent us pictures and or build diary etc! I think the J15 is a great looking car!

Are you building it to race or just for the road?

You could ask Tim Hoverd the caliper question!

Thanks for the welcome, the car will be road use with a few track days. Red body+grey chassis, same as the demo car.
Not got many pics at the moment, i always forget when im in the garage!

Anyone building a kit car would do well to equip themselves with a calipers (cheap digital unit c.£20) and a Zeus booklet.

Then all yo need to do is to measure the OD of the threads, and the pitch, and you should be able to identify the thread.

Sometimes bolts can be metric but with a finer thread, which should be listed under the metric fine section

If you had the calipers and did the measurements you could probably google the info you need, so the Zeus book isn't essential.

I'm 99.9% sure they are M10 fine, which is 1mm pitch, rather than the 1.5mm pitch on an M10 thread.

[Edited on 10/8/10 by r1_pete]

Im just going to update this thread for information sake.

I went to my local bolt shop which is normaly very good, and can confirm that M10x1.25 does not fit. So i am on the hunt for M10x1.00 as r1_pete suggested.

Oddly, i found a seller on Ebay selling the exact seirra bolts i needed, so i bought them and guess what, they dont fit my carriers. These bolts look like the right ones but are in fact standard M10

Also a visit to Ford dealer resulted in £6 for a pair! and am not sure if they will fit now.

When i bought my calipers with carriers they where advertised as sierra, but im wondering now if they are from another car?

Suspect the thread may in fact be 9mm , same as Focus front caliper . A decent vernier and zues book is a good investment as already suggested along with a set of thread gauges

After checking with thread gauges etc at work, i can 100% confirm the thread size is standard M10. But mine were in deperate need of cleaning out with a tap.
I guess i should have checked that first, oops!

Thanks.