13 replies to this topic

[sixtyeight]

I have just pressed in the rear trailing arm bush and had it machined down to 13/16" (0.813"). The new pin is a snug fit, could probably take a little more off the bush, but it looks like this...

 

 WP_20131027_003.jpg   20.69K   65 downloads

 

It has gone through the brass bronze to the steel backing..

 

Are there good and bad bushes to use here? Better ones with thicker brass?

 

Tim.

Edited by sixtyeight, 28 October 2013 - 01:09 AM.

[Cooperman]

The bushes should be phosphor-bronze, not brass, and they should not be steel-backed, they should be entirely phos-bronze.

They should be reamed out to 13/16" using the correct long reamer.

Buy the bushes from Mini Spares and they will be fine once fitted & reamed.

Where did you get those ones from?

[sixtyeight]

sorry I meant bronze! 

 

it's from minispares UK, from their trailing arm repair kit.

 

http://minispares.co...25.aspx|Back to

Edited by sixtyeight, 27 October 2013 - 08:15 PM.

[dklawson]

There are many old threads on this board discussing various methods of reaming the bushings to size.  I will not re-start those discussions/arguments in this thread but encourage you to search for the old topics.  They are quite informative.

[sixtyeight]

Thanks for your post Doug.

 

I have read every thread on here regarding reaming bushes. I have no problem getting the bush to the right size. The problem I have is the bronze being too thin as these are not solid bronze bushes rather steel backed bronze bushes which I assume are cheaper.

 

The hole in the bush is the right size. Has been measured at .813" (13/16").

 

If it were possible I would just order changeover trailing arms but that is not an option as I am in Australia.

[Cooperman]

Why not find a local machine shop and have a set of bushes made completely in phosphor-bronze.

[sixtyeight]

because I imagine that it would cost around $100 just to get a bush made up when they should be working fine as no one else seems to have this problem. I will replace it tonight with another I have here (which I expect will be the same) and re-ream the new one.

[sixtyeight]

can anyone link me to a 100% bronze bush as apparently these are available...

[sixtyeight]

ok so I've taken the bush which wore through to the steel out, and getting ready to put another one in.

 

This is the bush that I have.

 

 

As you can see the bronze is fairly thin. There is definitely more steel than bronze. If I put my reamer against it, I can't see any bronze, it's as though it's going to cut it all out! That is before it's even been pressed into the trailing arm.

 

Part number on the bush is SCP QH5083.

 

ID is .802"

Needs to be bored out to .813"

thats 13 thou taken out

thats .3 of a mm

.15mm of thickness needs to come off

Theres around .5mm thickness of bronze

so that leaves .35mm (13 thou)

 

that is all before the bush is even inserted so there will be even less bronze left.

 

does that all sound right??

 

I really don't want to put this one in just for the same thing to happen. Can anyone confirm the above part number is indeed the correct item?

Edited by sixtyeight, 31 October 2013 - 07:17 AM.

[tiger99]

That is definitely the wrong part. As has been said, it should be entirely bronze with no steel at all.

 

You are likely to be able to obtain suitable bushes locally, and they should not cost all that much to machine to size. Here, for instance, is a supplier of "Oilite" bushes, which if available in the size should be ok, although not the original material. Google for more.

 

http://www.getyourbe...CFWTHtAodfgwAfw

[xrocketengineer]

I got my radius arm rebuild kits from Minispares and they are definitely made of something other than bronze on the outside. If I reamed all the way through the bronze, I am not sure. Here is my build thread:

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

However, the old ones that came out of the arms were not all bronze either.

Edited by xrocketengineer, 01 November 2013 - 12:40 AM.

[Dan]

  Your installed bush has been machined down an awfully long way to get through the bronze layer.  Also more bronze has been taken off at the two ends while the centre is still relatively intact.  This suggests to me that the bush had closed up slightly at the two ends when installed.  How hard was it driven into place?  How was it pushed in?  If it was driven in without a suitable pilot and hit too hard the ends may close up like that, or equally if the bore was not spotless then any hard particles trapped under it would cause distortion.  Are you sure it's the right finished size?  Is it in that condition around the full circumference or just up one side?  If it's just up one side it would suggest that either the bush is not in straight or it was not machined true to the line of the shaft.  Was a ream with a long pilot to centre in the other end used?  It's possible of course that if the bearing and finish machined bush are properly in line, but the damage is biased one way, that the arm itself is distorted.

[sixtyeight]

ok. it was operator error. I followed a dodgy DIY guide somewhere on the internets. That was a good guide on how NOT to ream out a trailing arm bush.

 

I found a less dodgy method described on here, have re-done it, and it has turned out better than one I had done professionally years ago.

 

Moral of this story is don't take others methods as gospel, especially on the internet. 

 

It was still done in a DIY-esque fashion, as I don't have $150 for a reamer and have no idea of anyone locally who can do the work for me. In the end I converted a radius arm pin into a reamer. This is easily done with an angle grinder, a bench grinder, and two nuts to lock onto the end of the pin. If anyne would like a how to I can do one but after all is said and done, if you can, get it done by someone who knows what they are doing!!!

[dklawson]

I am certain that the bushes I removed and installed on my car were the same as the ones you and Xrocketengineer posted pictures of (split steel backed bronze).  

 

I'm glad you found a method that worked and that did not involve sanding or brake hones.