Warning Bolts!!

[snakebite]

Danger! - steering arm bolts – Jaguar Running Gear

I had cause to replace my steering arm, so armed with new bolts from John Gordon Jaguar Spares I started……….

I nipped the long bolt up with a socket prior to using my torque wrench………..the bloody head snapped off!

On close examination of the pictures attached you can see:

• The cross drillings for the retaining wire are not on the same plane with the lower hole dangerously close to bottom of the head, therefore seriously weakening it. As you can see from the original bolt, both holes are on the same plane in the middle of the head.

• The new bolt does not have a hardness value stamped on it unlike the original (8..

I rang John Gordons to get their view on the situation – they said that they have not heard of a bolt head snapping before and that Jaguar discontinued that bolt.

I rang our local Jag specialist – they said they had one bolt in stock but would order more - and, yes, they have a hardness value (8. with the retaining wire holes on the same plane.

The other 2 bolts are fine as they are supplied with the hardness value stamped on them.

May I strongly suggest that everybody with Jag running gear check the steering arm bolts for the hardness value before a catastrophic accident occurs!

[wilf]

Thanks for the warning snakebite, glad you spotted this now and not whilst driving the car, and yes, I shall be inspecting my own!

[kayjayd]

I'm doing this job right now on my kit so thanks very much for the advice. I was going to order new bolts from Wards or John Gordons tomorrow after your previous post on this subject. I think new originals is the route I'll take now. Cheers :thumb:

[stevee8]

Scary stuff & just as well it happened when it did.

Just to clarify the bolt strength markings, the first number multiplied by 100 gives the nominal tensile strength in N/mm2, the second number divided by 10 gives the ratio between the nominal tensile and nominal yield strengths.

eg for a grade 8.8 bolt, the nom tensile strength is 800 N/mm2 and the nom yield strength is 0.8 times this figure = 640 N/mm2.

[Sparticus]

Use cap screws. Higher tensile strength 12.2grade. If in doubt never use a bolt always use a capscrew.

Si

[cobracol]

Only do make shure you drill for lockwire, dont ask me how i know

[Miket]

Good thread dug up nearly six years later

[Shane]

Hi Guys,
I just stumbled on this warning and glad I did!
Are the original bolts available anywhere, or could you tell me what size and thread they are.
If I use cap screws would they have to have washers or not, any help would appreciated with this safety issue!

[Purple AK]

They are M12-1.25 Shane. The only metric fasteners on the suspension, everything else is Unified

[Shane]

Hi Chris, thank you for the info and pdf

I will order them.