12 replies to this topic

[lukemull]

hi
have had a rattling sound coming from the back end of my mini for about 6 months now and have finally narrowed it down to the radius arm bearing.

my plane was to fit this kit
http://www.minispare...=... REPAIR KIT

so my question is has anyone done this and if so , how easy is it to do ?

thanks

[shorty]

chances are you will have to re reem the radius arm

[Cooperman]

The plain bush has to be reamed out after installation. Reamer size is 13/16" and it needs to be quite a long reamer.
The other difficulty is getting the old bushes out, especially the needle roller one. Usually one ends up smashing the bearing end flange, getting all the rollers out, then using a sharp centre punch down the outside of what's left of the bearing casing until it can be pulled out.
Make sure you fit the plastic grease-retention sleeve between inner and outer bearings.

[mrbridger]

Unless you've got the tools and knowledge to do this job, it may save you a lot of grief to buy a recon one on an exchange basis and refit.

It cost me about £40 in garage labour to replace.

I discovered my car was crabbing due to a worn radius arm.

[carlnrtn]

The plain bush has to be reamed out after installation. Reamer size is 13/16" and it needs to be quite a long reamer.
The other difficulty is getting the old bushes out, especially the needle roller one. Usually one ends up smashing the bearing end flange, getting all the rollers out, then using a sharp centre punch down the outside of what's left of the bearing casing until it can be pulled out.
Make sure you fit the plastic grease-retention sleeve between inner and outer bearings.

Hi. I know this isn't my topic, but could do with some help with what you just said. I'm currently re-doing pretty much all the suspension and brakes and whatever on my brothers mini which has been sat around for a while. Just got to stripping the back end off and about to do this job. When you say "the plain bush has to be reamed out after installation", what do you mean?? No idea what reaming is, ha. Thanks,

Carl

[Cooperman]

The long pin which supports the arm and allows it to pivot is a very accurate ground surface. It has to sit inside a roller bearing at one end and a bronze bush at the other. Now, when you fit the bronze bush it squeezes in a little, so the long pin will not go through. That's deliberate as the inside diameter has to be very accurate to match the diameter of the long pin, so you use a reamer which is like a very long and accurate fluted drill. The reamer is pushed right through both bearings from the needle roller end to ensure it is running parallel. When it reaches the bronze bush it cuts the diameter to exactly the right size for the long pin. A drill would not be accurate enough as it leaves a rougher surface, whereas the reamed surface is smooth.
The reamer size is 13/16".
It's a lot easier than it sounds.
You turn the reamer and push it by hand using a crank handle arrangement. Some people use a power tool to push it through with, but I've found that doing it by hand is better. It turns very slowly, not quickly like a twist drill.
I hope this explains it OK.

Peter

[dklawson]

The link below is to a picture of the reamer I modified and use for radius arms. You'll note the straight flutes (which Peter mentioned) on the left side of the tool. The right side has a reduced diameter that I hold in a drill chuck. As Peter said, you want to do the process of reaming slowly and you also want lots of lubricant. I use a cordless drill on low speed to power the reamer in my picture.

http://home.mindspri...ArmReamer01.jpg

[0138dave]

Hi all would one of the 13/16 on of these do the job? http://www.lawson-hi...al Hand Reamers

Edited by 0138dave, 04 June 2012 - 11:42 AM.

[Tupers]

When it come to removing the old bearing we use slide hammer to pull them out and then an old 1/2" extension bar to knock the bush out from the inside.

We use an adjustable reamer like the one pictured on the right to ream the bushes to the right size.

[dklawson]

Without a pilot on the reamer to guide it and keep it in line with the bearing, a reamer has to be used very carefully.

See the picture I linked in my 2009 post. You will notice the pilot on the reamer shaft towards the right side of the picture.

[Ethel]

There's no mention of the length of the one in the link. I got one that's long enough to fit right through the arm from http://www.tracytools.com/, for about half that price too, best to ring them. As above unless you buy, the very expensive, Rover service tool, you'll need to improvise a means of running the reamer concentric to the needle bearing end of the arm. When you add up the time, effort & tool costs reconditioned arms look like good value, and they have the advantage that will likely have been on a jig to check for distortion. Though, they are getting more expensive as the supply of arms to recondition dries up.

Personally, I'd avoid adjustable reamers: they are cutting tools and as such remove, and need , more material than their actual diameter indicates. I have got good results "grinding" similar bushes with fine production paper wrapped round a suitably sized socket, but not on something as long as a radius arm, with the incumbent difficulties of keeping it concentric.

[stevede]

I did mine using a pals lathe. I wrecked the first kit before this attempt.

Unless you are certain about what you are doing on this safety critical part, as others have said, by the time you have bought the tools etc, it's easier, quicker & maybe less costly to go recon.

Best of luck whichever way you go.

Regards

Steve

[Carlos W]

I'll just be buying refurbished ones from minispares!