The 'E' Type Forum

Hi, I've done a stupid thing, rebuilding my rear subframe to fit new brakes etc. Ive managed to end up with 2 special bolts which I cant find a home for! They are 7/16 unf, with nuts and 2 washers each, 2 1/2" long with a 9/16 hex head. They are not the special bolts for the radius arms, those are 1/2 unf and already fitted. I have only 2 bolts for the rarb drop links, which are also 7/16 unf, so I've obviously mixed something up, but I cant figure out what I've done. Can anyone steer me in the right direction please? Note to self: always label these bolts!

Rear anti roll bar I think....Steve

Thanks, that would make sense because thats all I've got left to fit, but I dont understand the need for special bolts there, cant see a hex recess or anything.

Possibly a thinner head for clearance......without a setup in front of me I can't tell.....dont overthink it....Steve

Steve, I think you’re correct, from what I remember there is little room to pass a full size hex head beside another part.

Geoff

Steve Wrote:

Rear anti roll bar I think....Steve

Hello Steve,
No cigar I'm afraid.

That bolt with the thin head, is the bolt that secures the small rubber bush end of the Radius Arm to the Wishbone of a Series 1 car. Series 2 and 3 cars have a more conventional bolt, where the thread points towards the outside and engages with a threaded hole in the outer yoke of the wishbone that the hub carrier is attached to. To facilitate that entry direction, part of the hex head of the bolt has a flat machined down to the periphery of the bolt's shank to provide clearance so that the head of the bolt can pass by the shock absorber lower fulcrum boss. This clearance is also facilitated by a removable spacer collar.

With a Series 1 car, the bolt, which is a special bolt with a thin hex head, enters from the outside of the outside yoke, passes through a plain hole in the yoke (no thread), through the small bush end of the Radius Arm, and secured with a nut. The thin hex head of the bolt is driven into a shallow bore in the yoke, with the corners of the hex being an interference fit with the bore so as to stop the bolt from turning when the nut is being tightened. As a consequence of this system, the Radius Arm can't be detached from the wishbone without detaching the hub carrier from the wishbone.

Regards,
Bill

Spot on correct as usual Bill

C18296 is a special head 7/16 bolt used on the rear anti roll bar on some cars.....the original posted did say the bolts are not for the small bush on the sway bar that are larger 1/2in that he has fitted already.....what model car is this from?....Steve

Wrong or right this 7/16 came from an anti roll bar to drop link...7/16...shown here with a new bush ..iv seen this same bolt in the same position on more than one car

And Bill has pointed out the machined flat section on an S2 which is the ‘funny’ bolt I was thinking of.
What a wonderful pool of knowledge this forum shares

Geoff

C17149 is the thin head bolt as used on early cars with the head outboard for the small bush on the radius arm...as Bill mentiones....it is identical to the bolts above....later cars used a different bolt for the radius arm small bush and this topic has been discussed befor with suggestions that the C17149 was used on some cars for the anti roll bar....possibly becaus the C18296 wasn't available........Steve

As I mentioned in my original post, these are not the radius arm bolts.
A) those are 1/2 unf
B) they are already fitted
Rarb drop links makes sense, I'll bolt it on and see if all then becomes clear.
'68 model series 1.5 coupe
Thanks for all your thoughts.

Definitely the anti roll bar drop link bolts , I've just rebuit my irs on a series 1 4.2, they are very similar to the captive radius arm bolts, it had me stumped for a while
Ian

So presumably you fitted them to the roll bar-to-link position,small head faci g out. Can you see the reason for them?

Yes that's correct and no I can't see the reason for the thin profile head there are no clearance issues, maybe who ever built it at jaguar picked the wrong bolts off the rack, who knows, but it was definitely fitted in the roll bar to drop link bush on my car.
Ian

Well that has cleared up my confusion, thank you all for your advice.

Let me try to unconfise it......the bolts photod above are in fact the early thin head bolt for the small radius arm bush.....however there are quite a few cars that have these same bolts used in the antiroll bar....possibly due to unavailability at the factory or being used incorrectly later.......the correct anti roll bar bolt is listed as a special headed bolt however the usual suppliers only supply a standard bolt......Steve