Morris Minor Forum

That's really not a horrible amount of wear for a lower trunnion, Drew. Looks like someone kept up with the greasing. How did the pin look?

Congrats!

Tom

Pins weren't bad, but I will be replacing them anyways. Cheap enough to do while I'm in there.

Did some more disassembly today on the passenger (LH) side. Wound up removing the torsion bar as well, as I wanted to check all the bolts/washers/etc to make sure everything was okay. Glad I did, as C washer on the torsion bar was pretty chewed up. Present, but very worn. I'll assume the other side is the same and order a pair.

Will also be ordering new front suspension arms (the thin ones). Mine are both worn where they have rubbed up against the eyebolt. The heavy rear arms are fine, just those front ones need help.

Uprights seem okay, but I'd welcome any thoughts on the threads. The "check for wear" notes in manuals never help when you're not exactly sure what wear looks like...

So the plan now is to order the front parts I need this week and hopefully get everything reassembled in the next few weeks.

Doesn't look bad to me, Drew. I had ordered new kingpins and upper/lower trunnions as a set, expecting lots of wear in my 60 year-old car, but mine showed signs of frequent greasing, and were perfectly useable - however as I had the new assys., I just put them in.

The threads are "ACME" (pipe fitting) threads and should appear much as yours do - with the edges of the threads not having sharp points nor rounded off edges, but pretty much square-faced. The more important test is, with them clean and dry, can you detect much wear or slop in the trunnions when they are screwed on to the uprights to their normal position?

Tom

Those thread look excellent. Should be good for another sixty years. It must be chronic non-maintenance to cause wear to failure. BMC got much more confident with this design over the years. For Series MM the service was recommended every 500 miles. Then for most Minors it was 1000 miles and with the Marina it was 3000 miles.

It's entirely possible these were replaced at some point. Someone did take generally good care of it over its life.

I may still replace the trunnions (they're cheap enough) but I'll leave the kingpins be. Time to get front bits ordered so I can start reassembly.

The old trunnions would probably be fine, but the bronze bushing should be replaced, which required line boring after pressing them in. Replacements with pins fitted take care of that.

3/4 inch by 11 tpi so quite an odd thread. Some seem to have been cut with an almost square thread (original?) whilst some appear to have a 55-60 degree angle (Later Whitform copies?) with about 25-35 thou shaved off of the OD to take the total OD to about 0.715 inch. I couldn't find an ACME thread with those specs but would welcome any input. I'm hunting for some taps and dies for both these Minor legs and the 13/16 x 11 Morris Oxford ones.
Really hard to see the threads now my eyes are getting old. Anyone else care to take a peek at their suspension threads and tell me what they find?

Thanks

Rob

Edited 1 time(s). Last edit at 2018-04-01 01:49 PM by 0123.

Parts for the front are ordered and on the way. Didn't replace the kingpins, but did do top and bottom trunnions, rebuilt shocks, and a few other bits and bobs. Hope to have most things in early next week, and I'll have time to get out to the shop and get things installed.

I've a big drive with this car coming up in lat May, so if I can get everything installed in the next couple weeks I'll have plenty of time for sorting out before the trip.

Salt Lake City, UT to Grand Junction, CO. About 300 miles each way, plus some day drives when we get there. 700 or so miles for the 3-day weekend. My local club does a weekend drive somewhere every May, been fun to take the Morris the last few years. It's my most comfy car, my wife will actually ride in it (she's not a fan of convertibles).

As for greasing the trunnions, it is recommended to take the weight off the wheels and supporting at the end of the lower arms. In this way the normal bearing surfaces are not in contact and will allow grease to possibly flow into these areas. The most recent "Minor News" had a maintenance chart from the MMOC tech advisor and it implied only jacking and removing the wheel is required. However, with the suspension drooping on the stop there is still tension on the threads and on the same normal bearing surfaces. Actually the wheels don't have to be removed in order to grease.