Top trunnion confusion

[gridgway]

I had to do some maintenance of my front hub bearings. In taking off the the upright, I noticed that the U bracket was bent in quite a lot and that the poly bushes were badly squished. I thought I would get some new bushes and sort it out. I ordered new MG midget bushes from MGOC (here in the UK), but they are the wrong size. The originals on the car have a 5/8" OD crush tube for a 1/2" bolt (ID in the poly bushes 5/8"). The MG midget ones have a 1/2" ID.

Then I also wanted to change one of the stub axle assemblies as it had an issue, so I got one from MGOC (sent the old one back as it was an exchange unit).

So now I notice that the top trunnions are different dimensions. The original is a bigger (tapered) ID than the replacement MG Midget one.

So there's clearly stuff going on that I don't understand! I can't ask the factory for the obvious reason. Is it something like an MG Midget upright assembly with a different top trunnion - MGB maybe?

Any and all help gratefully accepted - thanks!
Graham

[gridgway]

So to update a little. I have been checking with the MGOC Spares people.

In summary I have two stub axle assemblies with different size top trunnions. They say that there was only ever one size on the Midget - the smaller tapered ID one. I sked if the bigger one could have come from something else like the MGB, but that has a different king pin size, so it's not that.

So not much further on really!

[Euan Hoosearmy]

If MGOC supplied you with odd replacement parts that don't fit, surely it's on them to supply the right bits.

When I received my bushes, I was confused as they didn't have a crush tube but one was mentioned in the instructions - this is the reply I received from MGOC on the subject:

"Autobush only include distance tubes where required. You should find that the bushes supplied are a snug fit on the fulcrum pin.
Unfortunately, they include a generic instruction sheet, which confuses." The bushes are a very snug fit on the 1/2 inch bolts.

[gridgway]

I'm pretty sure what I have been supplied is standard MG Midget kit. It's what I had on the XI that is not standard!

[jonclancy]

I’m afraid I can”t add any more to this, because I didn’t build my car. Is there any possibility of adding some photos, please?

Can they return your original stub axle assembly and you replace the kingpin etc?

[gridgway]

Looks the same as a standard one, just a bigger internal taper

[gridgway]

I have a solution that will work. A fabricator friend has turned down a standard set of MGB polybushes to fit the MG Midget trunnions so I'll get a standard MG Midget trunnion and put it all back together. If I ever solve the mystery of the bigger trunnion, I'll restore to what it was.

[jonclancy]

Glad you got that sorted,Graham.

A quick question: do your trunnions have different part numbers cast into them, please?

Just wondering if there is a (significant) difference li.e. as there is with the BTA 648/649 Fat Rack steering arms, and the later AHA Thin Rack Triumph items).

I see you have 2A4005 in the pic.