Morris Minor Owners Club

Hi

I'm replacing both bottom Trunnions on my 68 4 door moggy, an advisory after the last MOT, are they both the same, or is there a left and a right, if the latter, how can you tell the difference? Any tips appreciated

Regards

Richard

Trunnions will be handed, because the two kingpins use opposed threads. Hard to tell just looking at the trunnion, but you can definitely tell when you go to install a trunnion on the wrong kingpin!

ESM has kits you can look at:
http://www.morrisminorspares.com/front- ... uk-p830547
http://www.morrisminorspares.com/front- ... uk-p830546

The genuine BMC trunnions I have on the shelf are stamped 'L' (left) and 'R' (right).
It is no good just replacing the bottom trunnions and hoping for the best.
The swivel trunnion threads must be examined for wear and if any doubts to their serviceability the swivel must be replaced as well as the trunnion.
No good will come of fitting new bottom trunnions to worn swivel bottom threads as they will not last very long and you will be back to square one.

Hi Guys, thanks for your replies the one's I bought have R stamped on them! Phil, when you refer to the swivel, are you referring to the King pin? I am replacing the whole trunnions not just the bushes

Regards

Richard

Why not change the whole lot that is top / bottom trunnions and the king pin ... better safe than sorry !As phil said it would be a false economy to change just the lower / top trunnions as they all wear out at different rates and one bad one will soon wear out the new / good ones.

Without seeming to be pedantic and to supply a bit of background:-
The Minor swivel (which has the stub axle attached to it) is correctly named swivel and is called as such in the BMC Minor parts list.
A king pin is the secured pin that the stub axle rotates around as is fitted to the MG Midget/AH Sprite/A35/A40 steering/front suspension and is actually a pin and as it is the main steering pivot/locator is rightly called King (Pin).
The bushes in a Minor bottom trunnion are quite hardy and hardly ever need renewing. It is the male threads on the swivel pin and female threads inside the trunnion that wear. Usually brought on by the seal between the swivel and trunnion failing and allowing water and crud to get into the threads.
I would recommend that you fit some of Declan Burns swivel to trunnion seals on assembly.
Only if the swivel threads are in very good squared off profile should you consider fitting new trunnions. If the swivel threads are not as original profile and sharp pointed the swivel and trunnions should always be replaced as a matter of course.
The top half of the swivel bottom threads tend to wear most as the the trunnion pivot point in the bottom suspension arms is offset from the centre line of the swivel so load forces act on the top half of the threads and wear them.
By all means try a new trunnion on the old swivel threads but be aware that if there is any doubt as to the condition of the swivel and trunnion threads replace both swivel and trunnion.

Woops sorry correction accepted and my apologises as I have always called them "king pins" as a matter of habit over the years but I see how some people could get confused .

The swivel threads are LH for the left swivel and RH for the right swivel, and I think the new ones as supplied now are also marked in the casting.

I would second the use of Declans seals, I have just fitted them to my car with this winters front overhaul, much much better than what is supplied with the trunnions, engineered for the job.

I got away with my RH swivel, the threads were perfect and a new trunnion was fitted as a matter of course, the LH one was worn exactly as Phil says on the top part of the thread and more to one particular aspect of it. The fulcrum pins were quite worn on mine as well, but its the first time I have had the front apart fully and I don't know the history of what has and hasn't been done.

Happy to post a picture of the worn swivel later on so you know what you are looking for, but I am sure there are lots here already.

Regular greasing is key to long life, mine get done with a shot every 500 miles or so.

Thanks for all the replies and great advice and the obvious wealth of experience of club members! Where can i get a set of Declan seals please?

Thanks

Richard

If you private message Declan direct he will sort you out. Hes a good chap.

Thanks

Just messaged Declan

Happy motoring

Only got the PM this afternoon as I have been in hospital-see reply.
Regards
Declan

They will be in the post tomorrow morning.
Regards
Declan

hopefully all ok with you mate!

I have been in hospital

I hope you are staying well, Declan.

I will be very cross with you if you aren't.

One of your fans from Downunder
Don

Declan
Please tell us you'r OK!
Bob

Thanks all,
I am OK-sort of-just a problem with blocked hydraulics which need regular wire brush treatment. Master cylinder works fine!
Regards
Declan

Declan_Burns wrote:Thanks all,
I am OK-sort of-just a problem with blocked hydraulics which need regular wire brush treatment. Master cylinder works fine!
Regards
Declan

Glad your on the mend

I'm aware that the king pin threads used to be cut undersize and the appropriate trunnion fitted but that is all past. Would I be right to say that the kingpin is harder than the trunnion, so wears less quickly. This being the case, is there any rough guide, as to how many trunnions you wear out to one kingpin?

My car now has new front suspension and I wonder how many miles it will last, with 1000 mile greasing? Although it's nominally the runabout, I don't use it much (It's been laid up for a while, as I've just not had time to give it my attention and there are a few more jobs to do) and I commute by bicycle. It isn't likely to get a hard life and whilst if I have to go out, in the rain, the Morris will be the one to get wet, I do try to avoid it. I'm now not so far off retirement, so eventually (I hope) I will be better able to pick and chose when I go here or there....and I will have my bus pass (Even now I will hop on a bus, rather than use the car, especially is it means a none to clever car park....is there any other sort?).

As a rough guide to the number of trunnions to a swivel could be considered in the same vein as how long is a piece of string
There are too many unknowns to be able to give a rough guide.
The threads on the swivel must be considered as part of the inspection process. If there is any sharpness to the top of the thread on the swivel the swivel must be replaced. To reiterate - the swivel thread is 75% Whitworth profile so already has a flat peak when new therefore sharpness indicates serious wear and the swivel must be replaced.