38 replies to this topic

[Cooperman]

You can buy a 13/16" reamer for around £45 which is less than the cost of 2 exchange arms and you still have the reamer to do the job for other people.

[jime17]

You can buy a 13/16" reamer for around £45 which is less than the cost of 2 exchange arms and you still have the reamer to do the job for other people.

Fair point, but the more I think about it the more I realise the ways I can mess it up.

I'm usually a one for doing things myself as I then know care has been taken over it, but this is an area I've no experience in and I'd be concerned over making a costly error.

thanks everyone. all the replies have been excellent and really informative.

[Ethel]

I agree with A-Cell, I wasn't trying to put you off, just offer a few pointers so you're at least aiming in the right direction. At worst it'll cost you a replacement bush if it goes wrong. I've "reamed" kingpins using production paper taped around a suitably sized socket and got several years of MoT passes on the results, so I'm all for a bit of freestyle engineering.

http://www.tracytool...&product_id=544 - give 'em a ring to make sure it's long enough, they stock loads more than they list online.

[dklawson]

With limited resources, a homemade reamer used with some care should do just fine. I believe this is a MUCH better solution than some of the other DIY methods that are often proposed. I'd skip that lapping compound though. I hate the idea of leaving any behind.

[jime17]

Thanks guys. I shall start searching for best methods of removing the old bearings and bushes now.

[Vipernoir]

I'm lucky enough to own (and regularly use to refurb arms) the proper Churchill arm reaming tool - works a treat !

Having tried various methods of reaming the bushed out in the past (including free hand with an adustable ream) I can see how the use of a pin looks promising - however, and there is almost always a however...
Using an old pin means that it is probably worn in the crucial places - who wants to chop up a new pin - so from the off you're not going to get a true cut.
There is enough play in the roller bearing to allow a pin to wander.
Unless the reaming tool is long enough to pass through both sides of the arm, and is supported absolutely central and parallel to the bore, any reaming will lead to the pin being skewed and bizarre camber/toe. The proper tool cuts from the outside inwards, not the inside out and has a gert big insert for the roller bearing end to ensure straightness.

[tiger99]

I made one from the old pin in an emergency in about 1969, and just cut one groove with the angle grinder. The bushes lasted till the van was scrapped, about 40k miles, and were still slop-free.

Nowadays no-one would scrap a van of course, and by todays standards it would have been restorable, but in those days even the professionals did not have MIG welders, a rusty Minivan was of no value, and body panels were not easy to get or affordable. It was ruined by supposedly professionally fitted oversills, amongst other things.

[A-Cell]

Just a few things to add to this
To Ethel thanks for link to Tracy tools, I sometimes need reamere for other jobs and find they are very expensive, so that's a good recommendation.

To Vipernoir, I used a new pin when i did it, long time ago but at today's price £5.45 still cheaper than a reamer and certainly cheaper than an 18G tool, when somerford mini had them in stock they were over £400 - you get a lot of refurbed arms for that.
Perhaps you could help the OP jime17 out with your tool?

We all have created our own set of 18Gxxx tools to get round the tasks we are faced with, from bent spanners to ground down sockets. This is what the factory did. A bit chicken and egg really. Which came first the flywheel on the taper or the flywheel?

[MRA]

And how will you ensure that the concentricity (alignment) between bush and bearing, or bearing and bearing on older models is maintained ?

By eye ?? Not a chance of this being possible.... unless your names Steve Austen

[A-Cell]

Who's Steve Austen? Can he help the OP solve his problem?

[dklawson]

Steve Austin: a.k.a. the Five-Million Dollar (Bionic) Man. Old TV reference.

Martin, if you install the needle bearing first, the homemade reamer will be guided by it to cut the bushing concentric and inline with the bushing end. If it was suggested to use a pivot pin without the bushing installed... I missed that. I agree that not having the needle bearing installed first makes this a very risky procedure.

[jime17]

If it was suggested to use a pivot pin without the bushing installed... I missed that. I agree that not having the needle bearing installed first makes this a very risky procedure.

I missed that too doug. I'm not sure anyone did.

Thanks for all the replies with positive advice.

If the diy method last 20k miles that's over 5 years for my mini. And I have the satisfaction of doing it myself.


I've seen cooperman state that he's used duct tape wrapped around the non cutting end of a reamer and lubricated slightly to achieve concentricity with the bush.

If one were to, as martin warned against, ream without the roller bearing in place, but use tape as a guide if you will, is that likely that once installed the new roller bearing will be in line with the reamed bush or are there too many variables?

The reason I ask is , using that method one could use more of the pin to ream with rather than the very end before you ran out of roller bearing to guide it.


Also. Tiger, did you angle the cut and what did you use to turn the pin? I was thinking radius arm in a vice and spanner on two nuts?

Edited by jime17, 11 January 2013 - 07:18 AM.

[Guess-Works.com]

I honestly can't see the point for having a reamer to do this job....

When ever I have to replace the bushes, it's a quick simple job, to remove everything from the arm and go get a reconditioned arm, and I probably do this particular job more than the everyday mini owner. In fact the everyday mini owner should only have to do it once per car or there's something wrong with your maintenance.

I don't know how long it takes to replace the bushes and then ream, but I'm sure it's not less than an hour and at that rate, one hours labour is the cost of an arm anyway.

[jime17]

Fair point. But tenner for the pin kit against forty or fifty quid for recon and then postage for sending it back. I can spend what I save on the other million things that need to be done.... Or failing that. On the wife and kids!

[MRA]

The correct Churchill tool (I have one as well Alex) comes with the correct bushes to align the tool whilst reaming the bushing.

Using duct tape or the needle roller is a bodge, using the new bearing will guarantee faster wear due to the swarf from the bush, being careful may help and some of you may get useful results, however i'm with John on this one, getting a reconditioned arm should save a lot of heartache for a lot of other Mini owners.