[TR] TR6 rear shock mount break

[Alex&Janet Thomson]

Wow! Those pictures paint a dismal situation. Good luck with whatever direction you go in. Thanks for your detailed descriptions.

 

Alex Thomson

'73 TR6

 

From: Triumphs <triumphs-bounces at autox.team.net> On Behalf Of Tim Gaines
Sent: Wednesday, March 18, 2026 5:18 PM
To: DAVID MASSEY <dave1massey at cs.com>; Triumphs <triumphs at autox.team.net>
Subject: Re: [TR] TR6 rear shock mount break

 

 

Dave, I did check the Coil-Over kit, but it looked as if the job would be a good deal more demanding than than the one I'm into with the replacement cross member. That old cross with the shock mounts would have to come out either way, and since I have already refurbished the lever shocks, well  .  .  .  .  I realize that RATCO has improved the geometry of the shock system with the Coil-Over compared to the tube conversion that probably tore my cross member apart, but it seems to me that the design of the original lever shocks is as good or better. The ball joint in the levers allows them to follow the arc that describes the travel of the rear of the trailing arms (where the levers, or the tubes in the conversion, connect) without putting lateral pressure on the cross member. That is my thinking anyway.

 

And for anyone interested in the description of the RATCO Tower Kit installation I started last week:

 

Today was a good day in the garage. After several days with nasty weather and then some more with other demands, I lowered the jack under the diff so it could move down to its "cradle" formed by the 2 half axles and the drive shaft. I then cut through the short welds holding the left and right ends of the cross member to the frame rails. I was then able to lever the the cross up far enough for its studs to clear the diff and then slide the whole cross out.

 

The photos tell a sad tale: 

(1) Rear side:  Some of the metal that connected to the left rail was gone and small cracks are above that. I had to (straight) cut those connections on the right.

(2) Rear side again:  I had fabricated a patch to replace the missing metal in my original (aborted) plan.

(3) Front side:  The unreachable crack that scuttled the original plan.

 

The new kit has not shipped yet, but I still have some work to do anyway. The old welds on the frame I cut today need to be ground smooth, and then I need to used a flap wheel on the grinder to get the frame clean and shiny for the welds to come. 

 

Tim

 

------ Original Message ------

>From "DAVID MASSEY" <dave1massey at cs.com <mailto:dave1massey at cs.com> >

To "Stan Foster" <stan at redtr6.com <mailto:stan at redtr6.com> >; "Triumphs" <triumphs at autox.team.net <mailto:triumphs at autox.team.net> >; "Tim Gaines" on either<mtgaines at presby.edu <mailto:mtgaines at presby.edu> >

Date 3/13/2026 7:20:53 AM

Subject Re: [TR] TR6 rear shock mount break

 

Here's a thought.  Ratco sells a Coil-Over conversion kit that doesn't use the stock shock mounts at all.  Have you considered that?

 

Dave 

 

 

On Thursday, March 12, 2026 at 12:06:49 PM CDT, Tim Gaines <mtgaines at presby.edu <mailto:mtgaines at presby.edu> > wrote: 

 

 

It is a stormy where I am, so I'm inside with my laptop instead of under my TR6 working to get that rear shock mount cross member out. Somehow I must have deleted some of this thread, and I don't remember if I ever continued with my "fix" to the problem. I did carry it over to "The Triumph Experience" where I got some more recommendations, and though I was discouraged for a time, I am now very optimistic about my choices.

 

First, I got out the lever shocks that I had removed a couple of decades ago and opened them up and found the cause of their horrible performance. They were filled with grease! I found a Youtube video on the "Yakov's Beauties" site (so many great Triumph jobs there) that showed how to refurbish them. I did what he did and got a similar result where much more force was needed to move the levers. I really think they are going to work as is, but if not I'll get them done by one of the shops mentioned by others here.

 

Second, I did embark on an attempt to weld up and patch the cracks that had appeared on the left side of the cross member (gas tank out of course). I thought I could hold the pieces together with C-clamps and then spot weld them in a few places from underneath, up into the channel. The idea was to then add more to the welds in the channel and then weld patches to the outer surfaces of the channel that I would cut from 14 gauge sheet steel. I did get a couple of spot welds done, but the channel is narrow, the MIG nozzle is pretty wide, and it was very hard to see anything when the nozzle and my hand blocked the light. The killer was my discovery of another crack farther up near the differential that was in an even narrower spot. I called a local welder who was happy to come take a look at the possibility of doing a stick weld up there, but he said there was no way it could be done, and he thought the cracking would spread anyway. Total discouragement at that point because I just couldn't imagine incurring the expense of a frame-off job to install the RATCO Differential Tower replacement after post-Helene clearing and tree work had depleted our accounts.

 

A very helpful post on The Triumph Experience (from Ken D) let me know that the RATCO replacement could be done without removing the frame. "Read the instructions on the RATCO site," he said. I did, and the process sounded very doable, even for this 78 year old. I talked to Bob at RATCO, and got some good advice about carefully checking my frame for rust before proceeding. The cross member set up for lever shocks was not in stock, but it is likely to be shipped next week. Meanwhile I have been busy following the instructions. I'll briefly describe how things have gone for those who might be thinking of the same solution.

 

There was some initial frame prep required that would be very difficult to do without first making room by removing the hubs and half axles from the trailing arms and letting the arms hang lower. Each side has 6 nyloc nuts holding the hub to the cast aluminum trailing arm. All but one of mine came out nicely, but one nut was frozen to its stud, and that stud and nut unit re-tightened after several turns out. It was extremely tight and I feared stripping the aluminum threads in the arm by forcing it out. It took several hours (over a couple of days) of spraying Liquid Wrench, turning back in and then out, tapping the surrounding metal, applying heat with a heat gun (a torch might have been too much for the aluminum) to loosen the nut. It seemed interminable, but I did begin to feel that the nut was backing out a little farther on the stud, and it did finally give leaving the stud and arm threads intact. Whew. Another Yakov video showed how to simply pull out the hubs (no need to do anything with the diff). Mine were stuck, but I borrowed a hub puller with a slide hammer from Advance Auto (payed $175, got it refunded after pulling the hubs in 90 min). 

 

I used my little air compression driven grinder with cutting wheel to slice the shock bump stops from the frame sides (to be re-welded later to a frame collar in the RATCO kit). It was a tedious job. I borrowed a friend's Makita electric angle grinder with a 4.5" diameter, .040" thick cutting wheel for the cuts to the old cross member. The cuts on the front side of the old cross member to separate it from the frame were about 6" long and took less than a minute each! The same cuts on the back side of the old cross were hindered by the bottom of the trunk area where the gas tank resides. Only about an inch of the cutting wheel could cut until the body of the angle grinder was blocked from moving farther in. This was incredibly discouraging, and I think it is the only flaw in the instructions provided by RATCO. Maybe there are low profile angle grinders that could work? I finally hit on the idea using my saws-all with a good long Diablo metal-cutting blade (I do have a few of my own tools at hand). It did a good job of cutting the rest of the way and took only a few minutes. I have used a grinding wheel to smooth out the metal left on the frame after some of the cuts, and that has gone well.

 

Yesterday I reinstalled the hubs using just 2 new nyloc nuts on each. The hardest part (not really bad) was sliding the new rubber boots (old ones worn) over the splines in the shafts before pushing them through the trailing arms (held up with a scrap piece of wood). This next is the best thing about the whole job. Tomorrow I plan to place a jack under the diff, remove the 4 nuts holding it to the mounts (2 in the old cross), and then lowering the jack to allow the diff to settle into a cradle of the 2 axles and the drive shaft. The only thing left holding the old cross in place is an easily accessed half inch weld on each frame rail. Should take about a minute to cut through those and then pull out the old cross. There will be more grinding to smooth the frame surface in preparation for the new cross member. That cross will be positioned by slowly jacking the diff back up into the 2 stationary forward mounts and into the mounts on the temporarily movable new cross. Ingenious! At that point my nearby pro welder has agreed to do the welding to the frame.

 

The current price tag on the RATCO kit is $375 plus shipping. The welder charges by the hour, but I don't think it should take too long. Maybe $200 or so there; certainly less than $800 total for the fix. That is more than I thought it would take originally, but this is much better than having an iffy patch job or a car that sits in the garage until . . . ?

 

Tim  

 

 

 

------ Original Message ------

>From "Stan Foster" <stan at redtr6.com <mailto:stan at redtr6.com> >

To "Tim Gaines" <mtgaines at presby.edu <mailto:mtgaines at presby.edu> >; "Triumphs" <triumphs at autox.team.net <mailto:triumphs at autox.team.net> >

Date 10/8/2025 5:37:30 PM

Subject RE: [TR] TR6 rear shock mount break

 

I had those brackets and the stress caused the cross ember to be torn off the frame. I fitted the cross member from RATCO and switched back to lever arm schocks.

 

Stan

 

From: Triumphs <triumphs-bounces at autox.team.net <mailto:triumphs-bounces at autox.team.net> > On Behalf Of Tim Gaines
Sent: Wednesday, October 8, 2025 4:37 PM
To: Triumphs <triumphs at autox.team.net <mailto:triumphs at autox.team.net> >
Subject: [TR] 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? 

 

 

 

 

 

 

 


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