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Radius Arm (Dry) Repair.


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#1 Sovereign01

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Posted 05 July 2017 - 09:48 PM

I've extracted the L/H arm from the car, which meant moving the fuel tank to reach the shock absorber. As it turned out, this wasn't a bad thing as it revealed that the vacuum hose had broken and explained the smell of petrol inside the car! :D I got a new, thicker one from Halfords.

 

I bought a kit to carry out the arm repair: http://minispares.co...o/GSV1125.aspx?

 

I've managed to extract the old pivot shaft using a suitably-shaped rod and hammer (I don't know the correct name for the tool) as it proved very difficult to budge, examination of which revealed quite a bit of wear at both ends. I found that the roller bearing was broken, with rollers loose. Where I'm at now is that I don't know how to extract said bearing from inside the arm, as well as whether I need to also pull out the bronze bush and plastic 'lube tube' as those are also provided with the kit. And if I do need to remove the existing ones, how do I do it?

 

The Haynes manual was very detailed on how to get the arm off the car, but for actually servicing the arm itself all it said was to get a BL dealer to do it; the kit didn't come with instructions on fitting! :lol:  Any help would be much appreciated!


Edited by Sovereign01, 05 July 2017 - 09:50 PM.


#2 nicklouse

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Posted 05 July 2017 - 10:07 PM

you just knock them out.

 

the bronze bush will need reaming to size after fitting.

 

normally cheaper and easier to buy a recon arm.



#3 xrocketengineer

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Posted 06 July 2017 - 12:49 AM

Here is a clue, before Photobucket swallows the pictures:

 

http://www.theminifo...th-radius-arms/


Edited by xrocketengineer, 06 July 2017 - 03:36 PM.


#4 Sovereign01

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Posted 06 July 2017 - 04:16 PM

Here is a clue, before Photobucket swallows the pictures:

 

http://www.theminifo...th-radius-arms/

 

Thanks for the help, that looks like a really handy guide- as it happens my neighbour has a workshop so hopefully he'll be able to help with some of those tools that I lack.



#5 xrocketengineer

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Posted 07 July 2017 - 01:39 AM

Too late, pictures are gone.

#6 richmondclassicsnorthwales

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Posted 07 July 2017 - 09:15 AM

There are special tools you can buy, but as it is really just a one off job, you would be out of pocket as this would cost a bit.

 

Sharp pointed narrow chisel and hammer. The roller bearings are harder as they are steel sheathed, you really have to chip away at them.

The bronze bush comes out easier. Once the bronze bush is bent up at one end, you can use the old shaft to get it out by putting it in the other end and hammering it through, this should help push the bronze bush out. You will get the idea.

 

You can put the new bushes in by using a vice, or buy some threaded rod from B & Q, with 2 nuts and 2 large washers Put the rod through the arm and put 1 bush a time over the rod. Put a piece of cardboard against the bush to prevent damage from the washer which will sit against the bush next.  Then tighten the nuts on.

 

This will push the bushes in. Then you need to ream the bronze bush. A 13/16 reamer is needed. I think you will get the idea what to do, but this is one way to do the arms. Reamer needs to be kept as straight as physically possible as to make sure the shaft goes through correctly.

 

Tracy Tools Ltd on 01803 326430 will supply you with a reaming drill / reamer.

 

You will also be able to change the plastic cover too which is inside. Don't worry if bits of old bush go inside the arm, they are hollow and will have some grease, it won't hurt.

 

I am sure people will think this is ludicrous, but if you want to go the more expensive route, then buy a pair of arms already done, or source some body who has all the necessary tools. Not every body has pots of money to throw at a job, but at least this gives you a chance to have a go yourself.


Edited by richmondclassicsnorthwales, 07 July 2017 - 09:18 AM.


#7 Sovereign01

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Posted 07 July 2017 - 09:32 PM

Good call with the chisel and hammer; the roller bearing had already shattered so it didn't take many hits to dislodge (1/3 of its circumference is just gone). The bronze bush on the other hand proved to be a much tougher nut to crack, getting it bent up far enough to move using the shaft took a full half hour. Once that was done, taking out the plastic lube tube revealed that it was cracked and the grease inside was a (disgusting) mixture of yellow/green/brown.

 

What's puzzling me is that because the tube is wider at one end than the other (something I didn't realise when I got the kit), I don't know which way round it's supposed to go within the arm, if it's the wider or narrower end that faces towards the side of the shaft with the grease nipple.



#8 alex-95

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Posted 07 July 2017 - 10:32 PM

If the bearing casing has been rubbed through then it it likely the arm is scrap (well has been on both of mine that it's happened to) as the rollers damage the bore the bearing sits in. The small diameter end should go to the bush side I think as it will only go in one end and that end should have the larger diameter side tube. 



#9 richmondclassicsnorthwales

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Posted 08 July 2017 - 08:40 AM

You will work it all out, the tube will only go back in the roller bearing ens as I rememeber.

 

Same as the bushes, you can't go wrong, just be easy putting them in as not to damage the roller bearing edge, very easily done believe it or not.

 

It's a bit of a pig of a job, the hard part is the labour.

 

You'll get there !



#10 Sovereign01

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Posted 12 July 2017 - 08:25 PM

The inside of the arm is intact, it was the shaft holding all the rollers in place, only when I removed it did the bearing fall apart.
 
Thanks, I did what you said with the threaded rod and it worked a treat, my neighbour happened to have one he let me borrow. He also said he'd bring a reamer from his workshop but he hasn't so far- I'll ask him about it next time I see him. It was only while I was doing that when I noticed that like the lube tube one washer was noticeably larger than the other.

So the only remaining obstacle is the reaming, once that is done I'll be able to put everything back together. Why the bronze bush couldn't be the right size to begin with is anybody's guess.

Edited by Sovereign01, 12 July 2017 - 08:29 PM.


#11 tiger99

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Posted 13 July 2017 - 12:18 PM

The reason why it possibly can't be the correct size is that it compresses very noticeably when pressed into the arm, and a close tolerance between the bearing surfaces is required.

Having said that, "some" plain bearings are fitted accurately without the need for reaming. Camshaft bearings for example. So maybe it is possible, if the diameter of the bore in the arm is sufficiently well controlled. I have a strong feeling that it is possible, but the spares suppliers don't seem to be interested, as in some cases they can make more profit selling junk.

I changed a bone bush of roughly similar size in the steering idler of a Rover P4 many years ago and again it compressed noticeably but it was a good running fit on the new pin when assembled. Before pressing in, it was very loose indeed. Make of that what you will. (Possibly different grade of bronze could be significant?)

There is probably good business to be had by sorting out long-standing issues like this but maybe those who could do it competently are lacking the time. Something about swamps and alligators comes to mind....

#12 nicklouse

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Posted 13 July 2017 - 01:31 PM


There is probably good business to be had by sorting out long-standing issues like this but maybe those who could do it competently are lacking the time.

Strange how some refurbishers have done this with two needle roller bearings.



#13 THE ANORAK

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Posted 13 July 2017 - 02:30 PM

the bronze bush needs to be reamed "through" the roller bearing with the correct type of reamer to make sure it is reamed in line.

 

just reaming the bush is not the correct way to do it and to be honest i cant believe that  so many so called "experts" on this thread have not made this clear.



#14 tiger99

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Posted 13 July 2017 - 03:28 PM

Nick, yes I have seen those, and some early Australian models had two needle rollers. But often there is not enough meat on the outer end of the arm to safely machine for the larger diameter of the needle roller.

On the other hand, it is a good place to start investigating. For example, a stepped pivot pin and a metric needle roller at that end may be viable.

No need for a specially hardened pin either, it can be machined for needle roller inner sleeves, and then you only need to replace those, not the pin.

Furthermore, the strength limit is set by the root radii at the transition from full diameter to the thread diameter at each end, so a pin made from hardened and ground hollow stock, which is available, with a grade 10.9 through bolt, would actually be stronger.

I often with that I had a proper machine shop, to try some of these ideas.

Edited by tiger99, 13 July 2017 - 03:38 PM.


#15 Sovereign01

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Posted 13 July 2017 - 06:52 PM

the bronze bush needs to be reamed "through" the roller bearing with the correct type of reamer to make sure it is reamed in line.

 

just reaming the bush is not the correct way to do it and to be honest i cant believe that  so many so called "experts" on this thread have not made this clear.

My neighbour brought a set of reamers that I hoped to use, only to find out that none were the right size. The sizes went from a 23/32"-25/32", straight to a 15/16"-1 1/16". So I'm still without a tool that goes from 25/32" (the size of the bush), to 13/16". The start size is almost immaterial as long as it finishes at 13/16".

 

I did see an FB video that showed a guy reaming using the method you described, he'd welded his reamer to an old pivot shaft which he then threaded through the bearing.


Edited by Sovereign01, 13 July 2017 - 06:52 PM.





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