The Triumph Dolomite Club - Discussion Forum

As above.

Having seen so many threads lately about sheared bolts, I wanted to source some decent HT ones to minimise the risk. May even double up as suggested elsewhere. Particularly as I found the remains of a previous sheared bolt in the sump.

Though 2 x HT bolts should be OK. Shouldn't they?

I guess this is an easy bolt to just under/overtighten without the use of a torque wrench as they appear so small and insignificant. When you stop to think, there's a hell of shear force applied to these 2 little bolts.

Also, should the cam sprocket be threaded? Mine appears to be. I'd have thought the sprocket holes should be clearance to ensure it all clamps up nice and tight.

So what's the thread size please. Mild steel or stainless ???????

Err confusing thread this.
Holes are clearance on 1/4 UNF in sprocket.
Fine threads in cast iron are not normal but hey this is Leyland.
Sprocket is carbon steel (bit tougher than mild steel).
Cam is cast iron (drill with no lubricant).
Bolts must be first quality high tensile steel.

Check out Lee's engine thread.

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track action maniac.

The lunatic is out................heres Jonny!

Just had a look at a few of my sprockets Derek. I think the thread you see is just an indentation from the bolts.

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Sprintless for the first time in 35+ years. ... Still Sprintless.

Engines, Gearboxes, Overdrives etc. rebuilt. PM me.


1997 TVR Chimaera 450

Hello, dowel it.

Jeroen Rothman

Ah, could be........must be, especially as they have sheared before. The nuts hold on right to the end of the threads though. Will drill them through again to clear it.

Thanks Jeroen, I had thought of putting a couple of dowels in. Maybe

I reckon 2 new decent HT steel bolts will suffice (famous last words)

Camshafts are 'forged' not cast. A very different process. Ideally use socket cap bolts with sufficient shank to to almost fill the sprocket holes. DO NOT USE SET SCREWS, (fully threaded).

Regards.