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Re: [TR] TR6 rear shock mount break

To: triumphs@autox.team.net
Subject: Re: [TR] TR6 rear shock mount break
From: David P <frogeye@porterscustom.com> (ame8.swcp.com [216.184.2.128]); Sat, 11 Oct 2025 11:05:21 -0600 (MDT) SPF_PASS version=4.0.0
Date: Sat, 11 Oct 2025 11:05:20 -0600
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My tube set up mounts to the tail of the trailing arm and then to a L 
plate reinforcement to the body tub..Pretty solid.. 8 new bolts through 
3/8" plate. No chassis involvement. DaveP

Car came to me this way, so no clue about origins..

On 10/11/2025 9:17 AM, Tim Gaines wrote:
> I've been doing a lot of web surfing for videos and info on my problem 
> of the cracked rear cross member caused by replacing the original 
> lever shocks with a tube shock mount. I now see that the problem has 
> been widely discussed, probably here on Triumphs as well as on various 
> forums. I wish I had paid attention earlier. Inasmuch as both shock 
> setups bolt to the same mounting plate on the cross member, I had 
> difficulty understanding why the tube setup should do so much damage 
> compared to the stock lever shocks. Well, I just found an old thread 
> (Ken D, 2018) where one contributer (Walt P) explained a lot with 
> reference to Ken D's photo.
>
> "Ken was concerned about the angle of his lever shock link and 
> wondered if something was wrong. The consensus was that it was 
> probably normal unless the rear spring wasn't seated properly. Walt P 
> offered this great explanation.
>
> Notice the angles in the two lever-shock link-arm photos.
> Now, imagine that a standard Fixed Mounting of a shock absorber/damper 
> was used (between the frame & the TA) to replace the lever-shock & 
> link-arm.
> As the Trailing Arm pivoted through its full movement, would the Fixed 
> Mounted Shock Absorber be able to move- as the Link-Arm did?
> Or, would the Fixed Shock Absorber remain in place and rip apart the 
> relatively fragile frame that it was mounted on?
> Because that is exactly what happens when a Fixed Shock Absorber is 
> used to replace the Lever-Shock.
>
> Something to consider if the idea of a rear shock appeals to you.
>
> Some venders DO sell a replacement shock system that pivots with the 
> TA movement,
> but Others do not.
> Be aware of what you are seeing in the their ads."
>
> Well, I had already installed the tube shocks long before this 
> explanation came out, so I won't kick myself in the ass too hard. Some 
> of you may be interested in another aspect of the "fix" for the 
> cracking problem, namely putting lever shocks back on a new or 
> repaired cross member. I found a great "Elin Yakov's Rusty Beauties" 
> Youtube video that showed how to service the original lever shocks.
> https://www.youtube.com/watch?v=AxrBaaLEHpw
> I got out my own old pair, opened them up for the first time, and did 
> what the video showed. It turned out that Yakov's shocks were pretty 
> clean and in good shape. Mine looked bad inside, but I plowed ahead. 
> First, I noticed that each of mine had a grease zerk installed in the 
> cover, but Yakov's had a bolt (as do the new ones I have seen at 
> Moss). Even worse, mine had a load of grease in them and not much 
> else. Who knows who put those on! So maybe that is why my ride was so 
> bad, and that in turn was why I replaced them with the tubes. I wish I 
> had looked inside, but the idea of the tube conversion looked so 
> inviting back then. I soaked the units in degreaser overnight, after 
> drying filled the first one with motorcycle fork oil as per the video, 
> and it now offers great resistance to movement, just as Yakov's did. 
> In a few minutes I head to the garage to do the other one. I think I 
> am going to have two good lever shocks. Now I need to see if my cross 
> member can be removed without too much trouble (the left side is 
> actually unattached to the rail now) and repaired with some welded braces.
>
> Tim
>
> ------ Original Message ------
> From "Tim Gaines" <mtgaines@presby.edu>
> To "Triumphs" <triumphs@autox.team.net>
> Date 10/8/2025 4:37:00 PM
> Subject TR6 rear shock mount break
>
>> I have been hearing a slapping sound either under or behind me in the 
>> 1974 TR6 when I encounter even slightly rough pavement, so today I 
>> decided to sort it out. I thought I had found the problem quickly 
>> when I saw that the spare tire securing hook bolt had come loose, but 
>> no such luck. When I finally gave up on simple fixes and jacked up 
>> the left rear end and removed the tire, I saw that the cross member 
>> had cracked near where the after market shock mount adaptor bolts on. 
>> I did a quick check with the Moss parts catalog and that cross member 
>> is not available with them. So, I'm wondering if this shock mount 
>> replacement for the old lever shock (I installed a couple of decades 
>> ago) was a bad idea and put too much pressure on that frame member. 
>> It occurs to me that there may be some folks out there who have gone 
>> through this and can tell me just how a fix should be attempted.
>>
>> That crack shown in the photo seems to be only on the back side of 
>> the cross member. I have learned some welding skills in the last few 
>> years, and I have a mig welder, but I have never done anything under 
>> a car. I really don't like the proximity of the gas tank either. I am 
>> thinking that my local pro welder would be the guy to call on, but is 
>> this really something that can be fixed that way?
>>
>>
>>
>>
>>
>>
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
>>  
>>      Virus-free.www.avast.com 
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
>>  
>>
>>
>> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> **triumphs@autox.team.net **
>
> Donate:http://www.team.net/donate.html
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>
> Unsubscribe/Manage:http://autox.team.net/mailman/options/triumphs/frogeye@porterscustom.com

-- 
DBA Porter Custom Bicycles 2909 Arno St. NE Albuquerque, NM. 87107 ph 
505-352-1378  My World go here:WWW.PORTERBIKES.COM/

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    <p>My tube set up mounts to the tail of the trailing arm and then to
      a L plate reinforcement to the body tub..Pretty solid.. 8 new
      bolts through 3/8" plate. No chassis involvement. DaveP</p>
    <p>Car came to me this way, so no clue about origins..</p>
    <div class=3D"moz-cite-prefix">On 10/11/2025 9:17 AM, Tim Gaines
      wrote:<br>
    </div>
    <blockquote type=3D"cite"
      cite=3D"mid:emd0e412ea-e4a9-4ca8-86cf-f6d8fc0151f1@b4fa6347.com">
      <meta http-equiv=3D"content-type" content=3D"text/html; charset=3DU=
TF-8">
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      <div>I've been doing a lot of web surfing for videos and info on
        my problem of the cracked rear cross member caused by replacing
        the original lever shocks with a tube shock mount. I now see
        that the problem has been widely discussed, probably here on
        Triumphs as well as on various forums. I wish I had paid
        attention earlier. Inasmuch as both shock setups bolt to the
        same mounting plate on the cross member, I had difficulty
        understanding why the tube setup should do so much damage
        compared to the stock lever shocks. Well, I just found an old
        thread (Ken D, 2018) where one contributer (Walt P) explained a
        lot with reference to Ken D's photo.=C2=A0</div>
      <div><br>
      </div>
      <div>"Ken was concerned about the angle of his lever shock link
        and wondered if something was wrong. The consensus was that it
        was probably normal unless the rear spring wasn't seated
        properly. Walt P offered this great explanation.</div>
      <div><br>
      </div>
      <div><span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Not=
ice
          the angles in the two lever-shock link-arm photos.</span></div>=

      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Now=
,
        imagine that a standard Fixed Mounting of a shock
        absorber/damper was used (between the frame &amp; the TA) to
        replace the lever-shock &amp; link-arm.</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">As
        the Trailing Arm pivoted through its full movement, would the
        Fixed Mounted Shock Absorber be able to move- as the Link-Arm
        did?</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Or,=

        would the Fixed Shock Absorber remain in place and rip apart the
        relatively fragile frame that it was mounted on?</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Bec=
ause
        that is exactly what happens when a Fixed Shock Absorber is used
        to replace the Lever-Shock.</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Som=
ething
        to consider if the idea of a rear shock appeals to you.</span><br=

style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Som=
e
        venders DO sell a replacement shock system that pivots with the
        TA movement,</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">but=

        Others do not.</span><br
style=3D"clear: both; font-family: Arial, Helvetica, sans-serif; font-siz=
e: 14px;">
      <span
style=3D"font-family: Arial, Helvetica, sans-serif; font-size: 14px;">Be
        aware of what you are seeing in the their ads."</span>
      <div><font face=3D"Arial, Helvetica, sans-serif"><span
            style=3D"font-size: 14px;"><br>
          </span></font></div>
      <div><font face=3D"Segoe UI Variable Text" style=3D"font-size: 12pt=
;"
          size=3D"3">Well, I had already installed the tube shocks long
          before this explanation came out, so I won't kick myself in
          the ass too hard. Some of you may be interested in another
          aspect of the "fix" for the cracking problem, namely putting
          lever shocks back on a new or repaired cross member. I found a
          great "Elin Yakov's Rusty Beauties" Youtube video that showed
          how to service the original lever shocks.=C2=A0</font></div>
      <div><a href=3D"https://www.youtube.com/watch?v=3DAxrBaaLEHpw";
          moz-do-not-send=3D"true" class=3D"moz-txt-link-freetext">https:=
//www.youtube.com/watch?v=3DAxrBaaLEHpw</a></div>
      <div>I got out my own old pair, opened them up for the first time,
        and did what the video showed. It turned out that Yakov's shocks
        were pretty clean and in good shape. Mine looked bad inside, but
        I plowed ahead. First, I noticed that each of mine had a grease
        zerk installed in the cover, but Yakov's had a bolt (as do the
        new ones I have seen at Moss). Even worse, mine had a load of
        grease in them and not much else. Who knows who put those on! So
        maybe that is why my ride was so bad, and that in turn was why I
        replaced them with the tubes. I wish I had looked inside, but
        the idea of the tube conversion looked so inviting back then. I
        soaked the units in degreaser overnight, after drying filled the
        first one with motorcycle fork oil as per the video, and it now
        offers great resistance to movement, just as Yakov's did. In a
        few minutes I head to the garage to do the other one. I think I
        am going to have two good lever shocks. Now I need to see if my
        cross member can be removed without too much trouble (the left
        side is actually unattached to the rail now) and repaired with
        some welded braces.</div>
      <div><br>
      </div>
      <div>Tim=C2=A0
        <div x-em-replyforwardheader=3D""><br>
        </div>
        <div>
          <div>------ Original Message ------</div>
          <div>From "Tim Gaines" &lt;<a
              href=3D"mailto:mtgaines@presby.edu"; moz-do-not-send=3D"true=
"
              class=3D"moz-txt-link-freetext">mtgaines@presby.edu</a>&gt;=
</div>
          <div>To "Triumphs" &lt;<a
              href=3D"mailto:triumphs@autox.team.net";
              moz-do-not-send=3D"true" class=3D"moz-txt-link-freetext">tr=
iumphs@autox.team.net</a>&gt;</div>
          <div>Date 10/8/2025 4:37:00 PM</div>
          <div>Subject TR6 rear shock mount break</div>
        </div>
        <div x-em-quote=3D""><br>
        </div>
        <div id=3D"x313171a1f8234a6">
          <blockquote
            cite=3D"emd5c8a763-1113-4af3-8e7c-15365916cecd@0baed868.com"
            type=3D"cite" class=3D"cite2">
            I have been hearing a slapping sound either under or behind
            me in the 1974 TR6 when I encounter even slightly rough
            pavement, so today I decided to sort it out. I thought I had
            found the problem quickly when I saw that the spare tire
            securing hook bolt had come loose, but no such luck. When I
            finally gave up on simple fixes and jacked up the left rear
            end and removed the tire, I saw that the cross member had
            cracked near where the after market shock mount adaptor
            bolts on. I did a quick check with the Moss parts catalog
            and that cross member is not available with them. So, I'm
            wondering if this shock mount replacement for the old lever
            shock (I installed a couple of decades ago) was a bad idea
            and put too much pressure on that frame member. It occurs to
            me that there may be some folks out there who have gone
            through this and can tell me just how a fix should be
            attempted.
            <div><br>
            </div>
            <div>That crack shown in the photo seems to be only on the
              back side of the cross member. I have learned some welding
              skills in the last few years, and I have a mig welder, but
              I have never done anything under a car. I really don't
              like the proximity of the gas tank either. I am thinking
              that my local pro welder would be the guy to call on, but
              is this really something that can be fixed that way?<br>
              <div><br>
              </div>
              <div>=C2=A0
                <div><br>
                </div>
                <div><br>
                  <div><br>
                  </div>
                  <div><br>
                  </div>
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      <pre wrap=3D"" class=3D"moz-quote-pre">** <a class=3D"moz-txt-link-=
abbreviated" href=3D"mailto:triumphs@autox.team.net";>triumphs@autox.team.=
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nate.html">http://www.team.net/donate.html</a>
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    <pre class=3D"moz-signature" cols=3D"72">--=20
DBA Porter Custom Bicycles 2909 Arno St. NE Albuquerque, NM. 87107 ph 505=
-352-1378  My World go here: <a class=3D"moz-txt-link-abbreviated" href=3D=
"http://WWW.PORTERBIKES.COM/";>WWW.PORTERBIKES.COM/</a></pre>
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