Have I got faulty trunnions?
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Have I got faulty trunnions?
Hi, I'm new to the forum, and in fact I don't have a Minor, I am in the process of restoring a 1965 Riley 1.5. As many of you will know it shares several parts with the Minor, which certainly helps with obtaining spares. My question relates to the top suspension trunnions, which I have just replaced onto a new pair of Minor kingpin legs which I had re-drilled to accept the Riley steering arm in the upper position on the previously blank boss on the casting. When I apply the grease gun to the top trunnions, after a few strokes the grease emerges out of the threads of the plug which is screwed into the top of the trunnion, rather than from the bottom of the (top) trunnion where it screws to the kingpin. The trunnion is a genuine Unipart item. Thinking I had a faulty one I tried a repro trunnion, but the same thing happened. My question is, is this meant to happen? i.e. are the top blanking plug threads designed with a clearance as an intended exit route for grease to stop too much pressure being exerted inside the trunnion, or should I stop the 'leak' by running a bead of weld around this plug etc? I am concerned that the grease is emerging out of the top before the full length of the threads is lubricated. Any comments gratefully received, thank you.<br>
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I don't think the extra hole will weaken the swivel pin. A friend of mine had one with both holes and we couldn't figure it out why it was there. Also what's the deal with the second boss. Later I got a Riley One Point Five and it all became clear. Checking older cars you'll see just one boss. The higher steering arm is needed to clear the B Series gearbox in the Riley/Wolseley. The part my friend had must have been a universal replacement part.
Thanks for the replies so far- fantastic response in such a short period of time! I also considered the potential weakness of the 2nd hole but then read about the existance if 'standard' pins with both holes drilled. Also I concluded that the weakest point is probably where the top hole is drilled anyway, this would probably fracture before the lower hole, espacially as it's a larger diameter than the Minor hole. (Actually I gather the Riley/Wolseley hole is the same diameter as one of the the Minor van applications which has a thicker steering arm than that of the standard car). Incidentally, getting the hole drilled took a bit of searching- a local (Portsmouth area) machine shop wanted anything between £350-£700 (depending on the time it took them)- PLUS the cost of a tapered drill (circa £60K), but I got it done in the end by a machine shop in Kent for £150 all in, and they didn't even need a tapered drill as they 'span it up' on a lathe.<br>
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Phew!!! I was wondering! Well done finding new kingpins - they are more or less non-existent. But supplies have been promised - and promised - and promised! So don't throw your old one away just yet - one day it may be all there is ! I wouldn't worry about the grease leak - they all do that - and it lets you change the grease from time to time. You should of course make sure the trunnion is not screwd on to the king-pin too far - leave a full thread so there is no danger of it binding up on full lock - and this may also allow some grease to leak down the thread. I use Moly grease in my trunnions !



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Thanks again for all your replies, and the clear conclusion is the oozing out of grease is probably an intended feature. Got both sides almost done now. I found the new swivel pins on e-Bay. Just had a quick look now and there's currently a new one for sale. As a Riley 1.5 owner I'm well practiced at ferretting out parts obsolete since the 1960s so finding them was relatively easy, it was getting them re-engineered to fit the Riley at a sensible price which was the challenge. Also I'd recommend tracking down original trunnion kits- BMC / Mowog / BL / Unipart- compared with a repro set I had the originals have slightly tighter clearance on the pins & the lower pivot pin. Also the bushes & seals are marked 'Mowog' and thus likely to be more durable than modern copies.<br>
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I never liked the grease squirting out of the top either. When I did the swivel pins on my van which I had 10 years or so ago I roughened up and cleaned the new trunnion top caps and smeared them with Araldite. I then warmed them very lightly under the grill, the Araldite flowed out and set and sealed the tops. The grease then had to travel along the threads and came out the rubbers. I don't know whether this is necessary but I liked it better.
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And why are the 'plugs' on the top and bottom trunnions different? It looks like a screw in plug on the top but the bottom has something more akin to a mini core plug. Also the grease doesn't get applied from the end of the trunnion but from a bit further up where the suspension pin goes through. Does this lead to a dead area at the bottom of the trunnion that never gets fresh grease?
I have just replaced my trunnions and when I put some grease in the bottom ones one of these core type plugs popped out and I couldn't get it to stay back in. Had to take everything apart again and fit another bottom trunnion.
I have just replaced my trunnions and when I put some grease in the bottom ones one of these core type plugs popped out and I couldn't get it to stay back in. Had to take everything apart again and fit another bottom trunnion.

Because of the larger ( and much better!) 9" Riley drum brakes - it doesn't look there is room for the brake pipe to go round the bottom of the backplate. On the Wolseley 9" brakes there IS room - but the lower edge of the trunnion is still trapped by the backplate (as it is here on the R brakes) -and so it cannot 'fall off' the kingpin when badly worn - as it can do on the normal Minor drum brakes.



Some interesting comments, wish there was a Riley forum as lively as this! My response to some of the above points; the fixed brake pipe is a faithful (Kunifer) copy of the shape & routing of the rusted steel original. I have no experience of working on a Minor so can't comment on the way theirs are routed. The flexible pipe is sadly a repro item. 'Sadly' because it does not have the extended union of the original where it screws to the wheel cylinder, making fitment very difficult, I had to grind down a perfectly good spanner to make it fit so I could tighten it up properly! Re. the comment on the (Welch?) plug on the lower trunnions, I stupidly screwed the trunnion up too far initially and ended up with the thread of the swivel pin forcing the plug out! I took the trunnion off, put the plug back and peened over the surrounding metal with a hammer to secure it in place, whilst resting the other end of the trunnion on a block of wood to prevent damage. Yes I did back the trunnions off approx 1 turn after they bottomed out to enable inimpeded articulation lock to lock. Final snag- the OE trunnions have small ring shaped spacer (made out of softish metal- possibly aluminium) between the 2 lower pivot pin phosphor bronze bushes. Due to a machining error on the casting this did not 'move out of the way' as intended when the trunnion was screwed on, meaning it got distorted so the pivot pin wouldn't slide in! Spent ages struggling with this and in the end I collapsed it & hooked it out. My repro trunnions do not have this spacer. The only possible function I can think of is to physically stop the trunnion being unscrewed with the pin in place and thereby ruining the thread (As I have read here some have experienced!). The soft spacer physically prevents the trunnion being unscrewed with the pin in place. All this complexity and intrigue for such a seemingly crude piece of engineering! I'm enjoying the learning curve!<br>
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