Philidas Nuts for Brake Discs

[Phil P]

I thought this might be useful for anyone who is changing their discs or rebuilding their IRS. Philidas nuts (7/16in UNF) hold the discs and the ones that I was supplied permanently deformed the male thread onto which it was fitted.
Fortunately, I only fitted one to the point where the locking thread was engaging and this limited any damage.
Prior to fitting The Philidas one I had temporarily used plain nuts which wound onto the threads very easily. After use of the Philidas nut the plain one also became stiff showing the thread had been affected.
I contacted Philidas and visited their trade counter where the guy was able to tell me that it wasn't a Philidas nut at but a pattern part. There are 3 types of Philidas nuts as shown in photo. The second photo shows both the pattern part (LHS with knurling) and the correct Philidas Industrial nut. The correct one wound onto the thread easily and didn't alter it. Hope this may be of help.
Yours,
Phil

[44DHR]

Hi Phil,
Just wondered about your reference to “Philidas” nuts for the metal self locking nuts on the half shafts. I realise why there has to be a metal self locking nut, as opposed to a Nyloc type nut with a nylon locking insert due to the heat generated by the brake discs, but on all the many Jaguar diffs that I have worked on, I don’t recall seeing a Philidas type of nut.
The Jaguar Spare Parts Catalogue calls up part number C15349 (Nut, Self-Locking), but these are usually of the “Stover” type. These are longer in length and more substantial than the knurled type and are still available from suppliers, but many of the “usuals” offer the shorter 7/16in UNF knurled nut as shown in your second photo, which I personally feel doesn’t fit the bill in terms of looks or originality. S N G Barratts also offer this knurled nut as an “aftermarket reproduction part” alternative, but they do offer a longer and more substantial nut on their website as the original “Genuine” Jaguar nut and call it a “Nut-Stover 7/16” UNF”, although this is still not of the “Stover” design which has a rounded top in the locking area. I think the “Stover” type maybe because the nut locking area is slightly elliptical and it is as this top area is tightened around the bolt it grips it tight without damaging the bolt thread. Just a thought.
Hopefully the photo below shows the Stover design which is available from specialist fixing suppliers such as Spalding Fasteners. I have no allegiance with Spalding, but just wanted to give my alternative metal self locking nut which I feel more suits the original design.
Regards,
Dave

[Phil P]

HI Pil,
Thanks for your reply and had I known that they were available, I would have used the Stover type nuts if they are the original type. However, as I've now fitted the driveshafts and shocks, I shan't bother changing them.

It would be interesting to know what the Jaguar drawing for part C.15349 specifies. I suspect it may simply call-up an all metal locking nut so as not to limit the purchasing guys to a specific manufacturer.
Once again, thanks for your reply.
Yours,
Phil

[rfs1957]

The taller-type are also vastly better for guiding the socket properly.



The short knurled-type get chewed up very easily when we're going in at funny angles with a long extension, and can't see what we're doing.

I had to use a chisel to get one of mine off, and they were single-usage, no rust.

http://www.ajsengineering.com/

The type seen new in the picture are from Alan Slawson, who must use more of these nuts than almost anyone else in the world.

However, perhaps even more critical are the actual bolts.

My Jag originals were a very tight, almost press, fit into the flange, and once in place they stayed put.

The new ones I got from The Regulars were a good 3+ thou smaller, meaning they're constantly falling out of place, which is a MAJOR source of frustration and wasted time during any IRS/drive-shaft/caliper/disc work.

If anyone knows where to get ones with the original, fuller, diameter, they should pipe up.

[rfs1957]

Here are the bolts I refer to.



The pattern ones measure 11.06mm on the parallel shank, the originals 11.14mm

Not only are they a right PITA when they won't stay in place, but that is one LOT of metal missing for a shear context, where movement encourages wear, encourages movement, encourages wear etc

Must ask Alan Slawson what he uses.