Morris Minor Owners Club

Hi, just musing on whether engine mounting bolts, propshaft to diff bolts etc are high tensile or not?

I'm not sure either but the numbers cast into the bolt heads will tell you for sure.

Not sure what you mean by high tensile, but Grade 5 are probably adequate.

"Grade 5" is a High Tensile grade across the pond. In the UK, if a UNC or UNF bolt has three radial lines on its head, it's HT. R, S, or T on the heads of BSF bolts indicate increasing strength, and all are High Tensile, though some would say that R grade is a bit borderline. Metric bolts may be marked 6.6 (not HT) 8.8 (fairly HT), or 10.9 (HT).

This is oversimplified, but a starting point. I'd certainly use HT for prop shafts. Not sure which ones you mean by engine mounting bolts, but if in doubt, use HT.

Kevin

Are the prop bolts not special 'fitted' bolts anyway?? And the engine mounts don't have 'bolts' as I remember??

Reaming the holes for fitted bolts would surely have been too expensive for BMC assembly lines? It's enough of a fiddle poking a 1 1/4" bolt through and holding it, let alone turning a reamer. Moss don't show the bolts as anything special in the Midget catalogue. I'd have to stand up to check a Minor parts list, and icba. Probably worth a reminder to use bolts not set screws, and new nylocs.

Engine mount brackets to body? Set screws, iirc.

Kevin

Ahh the brackets - yes, but the mounts just need nuts. I just seem to remember the prop bolts are very snug in the holes - no looseness. I don't imagine they actually reamed them - just a well toleranced hole I suppose.