[TR] TR4 Investigating replacing the Armstrong lever shocks with telescopic rear shock conversions

Jim Henningsen trguy75 at gmail.com
Sun Dec 6 13:00:09 MST 2020

I've done the tube shock and won't do again for the reasons in the pictures.
I have rebuilt levers from Worldwide Auto in three of my TRs and they are
great.  I even have the uprated.  I DO NOT recommend them for a TR4 as they
are really hard.  Rides like a buck board with the leaf springs. I am
switching out to a stock rebuild.  Jane at Worldwide mentioned only get
uprated if you are racing.  


Jim Henningsen

Ocala FL

61 3A

62 4

67 4A

75 6

81 8 


From: Triumphs <triumphs-bounces at autox.team.net> On Behalf Of Brian Kemp
Sent: Sunday, December 06, 2020 1:50 PM
To: Will Daehler <will.daehler at gmail.com>; triumphs at autox.team.net
Subject: Re: [TR] TR4 Investigating replacing the Armstrong lever shocks
with telescopic rear shock conversions


Will - I'm not as familiar with the solid axle of the TR4, so this may or
may not be relevant to your situation.  

There are at least three styles of tube shock conversions for the TR6 and I
assume the 4A.  The one with three triangular brackets that go through the
body (likely the one you looked at from Moss), A bracket that bolts to the
body with no frame attachment, and a single plate bracket that bolts to the
lever shock mount.

Also watch for feedback on people that just get the lever shocks rebuilt
with a heavy duty rebuild.  If I was starting over, that is probably what I
would do.

A sample of the three plate design at Moss is 670-128 - see
https://mossmotors.com/rear-tube-shock-conversion-kits - the Monroe shock
version for the 4A is available.  They have an article at
http://www.mossmotoring.com/tr6-tube-shock-conversion/  It looks like a
sturdy design, but takes significant effort to install.  Read the
instructions from their website.

I do not recommend the bracket that just bolts to the body without a frame

I used the single plate version because it was much easier, but this design
leads to flexing of the frame cross member and cracking of the frame,
including mine.  See the 0091, 2217, and 2218 images attached of other
people's cars discovered at a local club tech clinic.  If you have this
design, I recommend you check the frame cross member regularly.  If you have
the rear spring out for any reason, run the trailing arm through its full
range of motion and you will probably see the top of the shock mount move
front to rear.

After having my frame cracks welded, I built a new version of the single
plate design available from some vendors.  I extended the top mount for the
shock back about two inches and added two braces.  One is a length of 1"
angle iron that goes between the two shock mounts near the top of the
bracket, just below the body to side to side stability.  The other is the
more important addition and goes from the top of the shock bracket rearward
to the frame at about a 45 deg angle.  This one stops any front to rear
motion of the shock bracket.  Unfortunately the car isn't easily accessible
right now and I can't find my pictures.

Below is an item I wrote 20 years ago or so.  The 5-6025 kit is the single
plate design that in my opinion needs at least the added bracket from the
top of the shock mount to the frame.

Tube Shock Conversion Notes

Notes on my TR6 tube shock conversion: 

> Would like to know if anybody on the list has any knowledge or experience
> the shock conversion kit that v.b. sells as part #  5-6025. It is listed
> page 11 in the summer catalog.......

I put similar brackets on my car.  They are the easiest design to fit,
taking about 30 minutes to install.  I purchased my brackets from someone
who made them for his car for $40.  I bought the shocks from Pep Boys for
$12.95 each.  The VB shocks must be pretty good to command the $189 price
tag.  My driving can often be aggressive, especially at autocross events
(2nd place in class at the Moss festival and first overall at Triumphest in
1998).  The cheap shock seem to work fine for me in the rear, though I may
just not know any better.  The PO put Koni's on the front.

Installation made a tremendous improvement in my car, but that's because my
lever shocks were dead.  I've heard lots of good things about the heavy duty
rebuilds to the lever shocks.  Doing it again, I'd give this serious

Disadvantages of this design:
- When the car is in the air, the limit stop for the trailing arm travel is
the tube shock.  I had a shock fail after only a year (exchanged for free
replacement).  I think the other one may also need replacement, as there's
oil on the tube.  This tension is transferred through the shock to the
bracket, at a slight angle, torquing the frame cross member that holds the
shocks and rear differential mounts.  I mention this because I just
discovered several broken welds including both rear differential mounts and
the crossemember to frame connection near the right shock mount.  The car
had the differential reinforcing brackets installed for the DPO.  I don't
know if the shock conversion caused this, but I think it aggravated the
problem.  (Any comments on this from others?)

- You are limited in tire width to 205 series tires, which may rub the
bracket if you have lots of camber or weak springs.

Safety considerations:
- The Gabrial shocks I purchased only have a single nut on each end of the
shock. The guy I got the brackets through had a shock come undone.  Your
shocks should be double nutted.  I used a nylocs because I had a box of
them, but any nut should work.

- Check the tires and brackets for rubbing.  I have a little bit on the
right side recently, but nothing I'm concerned about.  I can't see any
indication on the tire, just some rubber dust on the bracket.  I run 205/65
tires and will adjust the camber on the right tire.

If your into welding, you can make your own brackets looking at the picture.
Drop me an e-mail and I'll look up the shock number again.  It's off 50's
Studebakers and Cadillacs if I remember correctly.

The Moss kit is an effort to install.  It has three triangular brackets per
side.  One to the standard shock mount, the second inside the body by the
fuel tank, and the third in the wheel well area.  The first step in the
instructions was to remove the fuel tank.

I'd always avoid a shock that only bolts to the body.  The dampening forces
need to go to the frame.


On 12/6/2020 8:34 AM, Will Daehler wrote:

When going over bumps in my TR4 I have quite a rattle from the right rear
area of my car.  I have poked around by the axle, and thought I have fixed
the problem a couple of times.  I have replaced the springs and refilled the
Armstrong shocks.  I have poked around. While looking through my Moss
catalog I noticed the kits for replacing the Armstrong shocks with these
brackets that you could mount shock absorbers to. But the kits are NLS.  No
Longer Supplied.  I was wondering why the kits  were discontinued.  It could
have been that they caused damage to the frame, or just didn't work.  I was
hoping somebody had any first-hand knowledge or experience on this topic
that they could discuss. I wonder if the racing group all have custom and
proprietary set ups.


Will Daehler

63 TR4  

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