Mini top arm

[terryreed1664]

I have just finished refurbishing the front suspension on roadster. This involved stripping the whole front suspension. Whilst trying to undo the top ball joints, ( both sides ) this proved impossible ( nut splitter involved ) the nut was just going round along with the taper of the ball joint, yes even with the nut and lock tab washer in place it was still lose in the taper. ( just nipping ) Now you might think the previous person just hadn't tightened it enough. This was not the case the taper sits just proud when inside the top arm, the tab washer sits on this little shoulder so when the nut is tightened it only tightens down to the tab washer. This was solved buy placing a washer over the taper so after tightening the new nut down the taper was tight.
Has anyone else come across this problem!!!
Terry

[stevejgreen]

Re: Mini top arm

I beleive there are two different sized tapers on the Marina Top swivel. The larger one being the later model Marina where there were some redesigns of the marinas poor handling.
I'm guessing from your description that is your problem.

[terryreed1664]

Re: Mini top arm

Hi Steve, Thanks for the reply. It would appear the taper on the mini arm and the taper on the ball joint are the same when assembled dry. It maybe that the taper on the ball joint is a little longer.
Terry

[stevejgreen]

Re: Mini top arm

Interesting.
I have just been out to my parts bin
Mini tapered hole is 0.645" thick.
Taper on swivel is 0.75" long from approx 0.57" 0.48"
On my dry assy the taper is about 0.030" inside the Mini arm, rather than outside as you suggest.

You may have some wear on either or both parts. Provided though you have good taper contact (check with a little griding paste between them) then there would be no problem in fitting a 1/2" washer and let the taper pull through it to lock up securely.
Incidentally I always lap the top swivel bearing into its cup and sprung bottom pad. then tighteneing the top swivel nut and locking it off when the joint is just hard to move by hand. This seems to get around some of the poor manufacturing tolerances.

If

[stevejgreen]

Re: Mini top arm

Just checked manuals for marina. The variation of top swivel is purely a rubber bush in the lever shock absorber fitted in early models, that was later deleted.
I can only assume that what you have is a swivel that was locked down on the large dome nut and the rotation being the taper in the top arm, not the ball joint. That would account for wear to the taper joint.

[terryreed1664]

Re: Mini top arm

Hi again Steve, I checked the taper with marking blue and all seems to be OK. The Mini taper is as you say 0.645 thick I'm not sure about length of the taper on the ball joint but is slightly longer approximately 0.25mm so not a lot. The ball joint it self is in good condition with little if no wear.
Its a bit of a puzzle
Terry

[stevejgreen]

Re: Mini top arm

Without relevant bits in our respective hands it will be difficult if not impossible to locate the wear, if there is any.
I had a problem with a Mini wishbone moving fore and aft on its shaft. Ended up shimming it to remove the play.
I now have complete sets of parts for both sides, so when it comes for the next rebuild I will be ready.