[TR] TR4A trailing arm shims

Jack Mc McGaheyRx at aol.com
Sun Jan 11 16:19:17 MST 2015

Tony - 

I am also installing GoodParts CV jointed axles on a IRS TR4A at the moment and I found the same thing - I think there were 5 shims behind every bracket, plus a couple of non-original smaller shims that must have been added at some point for alignment. I have remounted the trailing arms with no shims (for now) thinking I'd let the alignment shop sort out how many should be where, but I have noticed the bump stop dish on the trailing arm on one side no longer lines up with the bump stop on the body. 
I haven't looked into that any further because I am distracted by a more immediate problem: 
The outer CV joint boot and boot clip are making contact with the trailing arm - I've never had this problem on the many TR6s I've done this to - so I measured and found the tunnel in the TR4A trailing to be smaller than any of the TR6 trailing arms I have on hand - hard to quantify how much since these tunnels taper, but looks like the TR4a trailing arm tunnels are a little over 0.1 inch smaller in internal diameter. Have you encountered this? 
As an aside, there are quite a few subtle differences between the TR4a trailing arms and TR6 trailing arms - and the quality of casting looks better with the TR4 trailing arms - the quality of casting got better during the TR6 model run, but these TR4 arms make early TR6 trailing arms look crude by comparison. 

Jack Mv

Sent from my iPad

> On Jan 11, 2015, at 5:23 PM, Anthony Rhodes <spamiam at comcast.net> wrote:
> I have been upgrading my IRS axle to the Goodparts CV joint axles.  
> As I did the second side I see that there are lots of shims under both the trailing arm brackets.  It seems to me that it may be possible to remove an equal number from each bracket.  I think that in this way it may be possible to preserve the geometry and get a bit more bolt thread available for the nuts holding the brackets.  
> This will change the fore-aft and the in-out position of the trailing arm.  But do you think the trailing arms were adjusted to that they were perfectly co-axial, and equally spaced?   I would doubt it. I would havevm thought the shims were used only to adjust toe.
> But then why so many shims?   I would have expected one of the two brackets to have zero or 1 shim, and the other bracket would be shimmed to get the toe adjusted properly??? 
> -Tony
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