Morris Minor Owners Club

Excellent - I thought it looked ok but best to check

Many thanks

Test will be when you screw on a new trunnion - how does it feel ?

I'll let you know when the new one arrives, old one felt fine coming off anyway.

Run it right to the top of the thread - then undo one turn. I use Moly grease on these - extra slippery.

Quick question - by the way I have Marina discs on the car!

I need to replace the 4 bolts that hold the disc backplate/cover to the suspension leg. Are these bolts toughened/hardened or will normal decent quality bolts do?

they are hardened i beleive

Do they just hold the 'cover' - or do they also hold the caliper ?? If caliper - then yes very high spec bolts required.

Both really I think.

In the picture below, the bolts circled in red hold the backplate/disc cover to the suspension leg.

The two holes circled in blue are the bolt holes for the caliper, which fixes to the backplate/disc cover.

The caliper is secured out of the way with a cable tie at present.

I'm guessing the 4 red bolts hold a bracket - to which the caliper bolts using the blue holes. Yes - they will all need to be High tensile bolts.

Thanks folks.

The trunnion arrived today and I got some new hardened bolts.
Ready to go right? Wrong.

The new trunnion is more loose on the swivel pin than the old one was. The old one just about unscrewed by hand (I did take the pin out first) whereas the new one will fly up the threads with barely finger pressure.

I'm pretty sure the swivel pin threads are ok, what now? Do I need yet another trunnion?

Only extra info is that I was trial fitting the new trunnion so had no grease on either it or the threads on the swivel pin, surely that wouldn't make so much difference?

It should run up the threads - that's ok - but when it's there - is there any 'rocking' on the threads ? If there is - more than a tiny amount - then a new kingpin is required.

There is movement on the new trunnion, but only a tiny amount.

What is confusing me is that the new one has a tiny bit of movement on the threads, while the old trunnion had less, barely perceptible.

Well - I suppose the threads may have 'worn in' together. It's up to you if you feel either is acceptable/safe. And yes - it could be the new trunnion has quite 'loose' threading - new parts these days ........
There is a thread somewhere about making a bracket to 'catch' the trunnion and prevent it coming off the kingpin. My 9" Wolsleley brake backplates do that automatically! Equally - a tele front damper conversion will also hold the lower arm and prevent the trunnion ever escaping from the kingpin.

Thanks for that. You've hit the nail on the head - I'm not happy to fit the part. I'll contact the supplier and see what they say.

Thanks again.

I'd go for a new swivel pin, the upper threads on yours do look worn, and to put a new trunnion on will just wreck a good trunnion. Its not worth the agro really as new parts are very reasonable and the alternative failure is a real pain.

Thanks Jonathon. I think thats what I'll do. I 'll get a new swivel pin plus top and bottom trunnions fitted over winter, I don't drive it when the roads are salted anyway!