Subject: Re: [TR] TR4A IRS Suspension Question

From: Steve Kirby <[email-masked]>
Date: Wed, 24 Mar 2021 00:16:33 +0000

Jim

Others may be able to offer you more insight, but you should keep in mind that shock absorbers do no influence ride height because they bear no weight.  The "gas" in gas shocks is insufficient to raise the weight of your car (after all, you can compress the shocks by hand).  If your rear ride height changed it was due to other factors.

In a race car, the first thing that the builder would do would be to weigh all four corners.  If the LF of the car weighs more than the RF, then the car will not sit level on exactly the same suspension components.  

Steve Kirby
President
China Auto Group
22831 Avenida Empresa
Rancho Santa Margarita, CA 92688 USA
Direct:  (949) 261-8208
Fax:  (949) 767-5949
Cell:  (949) 903-0957
Skype: steve.kirby29
www.chinaautogroup.com

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of Jim Henningsen
Sent: Tuesday, March 23, 2021 5:06 PM
To: [email-masked]
Subject: [TR] TR4A IRS Suspension Question

Ok, just finished redoing front and rear suspension on my 67 4A IRS.
Complete disassembly, clean, repaint, new urethane bushings, tie rod ends, trunnions, etc.  New comp springs ( 1 inch lower) all corners, new stock tubes shocks up front and new KYB gas shocks on the tube shock conversion brackets for the IRS.  Reinstalled all alignment shims as installed as the car drove pretty straight.  Urethane packings on springs. 

After completing, I noticed that all four corners have a slightly different ride height when measured from garage floor to bottom on fender lip at center of each wheel.  Left front: 26 3/4 inches, Right front: 26 1/4, Left
rear: 27 3/8, right rear: 27 7/8.  I think the higher rear height is coming
from the tube shock conversion as it was lower with the levers.    So about
a half inch off each side.   I don't recall having this issue when I redid
my TR6, but that was a while ago.   Rears also have stock trailing arm
brackets (one and two notch brackets on each side - believe these are original from new given history of the car).  

Looking for help on next steps before bringing it in for an alignment.  Will alignment correct height difference or do I need to add 1/2 inch spacers on lower sides.  I am going to put uprated valved levers back on rear to eliminate the extra height in rear.  

Any help appreciated.   

Thanks
Jim Henningsen
Ocala FL
Too many TRs to maintain!
61 3A
62 4
67 4A
75 6
81 8

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---

From: Jeff Scarbrough <[email-masked]>
Date: Tue, 23 Mar 2021 20:47:05 -0400

Is it also possible to measure to a different reference, like the
frame?  Could a 1/2" difference be due to factory assembly rather than
suspension?

On Tue, Mar 23, 2021 at 8:18 PM Steve Kirby <[email-masked]> wrote:
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From: Michael Marr <[email-masked]>
Date: Wed, 24 Mar 2021 01:02:41 +0000

Have you driven the car?  A few road miles will help the suspension settle.  There's a lot of "stiction" in those new components.

Also, I agree with Jim Kirby - the new shocks will not affect ride height, unless, for some reason, they have bottomed out and are bound up.

Mike

Michael J Marr, P.E., CEng.
Albion Technical Services
W5918 Hackbarth Rd
Fort Atkinson, WI 53538

Cell:  630-202-0065
Email:  [email-masked]

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of Jim Henningsen
Sent: Tuesday, March 23, 2021 7:06 PM
To: [email-masked]
Subject: [TR] TR4A IRS Suspension Question

Any help appreciated.   

Thanks
Jim Henningsen
Ocala FL

Archive: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.team.net_pipermail_triumphs&d=DwICAg&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=HL4LAX-jeuoWNeqz1u1ryqDHfrhQ38xO3ECYGpjCniQ&m=zyBcU6XFtctFx40MN8_0LZLMiP0J64CGZLrOiMB5Qo8&s=uGxnWgFKz5KyXyIy_wdVaNXa3hjX1Xy154hf3oSjnUc&e=  https://urldefense.proofpoint.com/v2/url?u=http-3A__www.team.net_archive&d=DwICAg&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=HL4LAX-jeuoWNeqz1u1ryqDHfrhQ38xO3ECYGpjCniQ&m=zyBcU6XFtctFx40MN8_0LZLMiP0J64CGZLrOiMB5Qo8&s=HjQYVeWw7RQvQxXSaopXQe1MIYbdNMn9gy8hgfGL66w&e=

---

From: Michael Marr <[email-masked]>
Date: Wed, 24 Mar 2021 01:17:41 +0000

Another thought.  On my TR3A, there is a spacer on one of the rear springs that, effectively, increases the unloaded ride height on the driver's side to account for the fact that the car is driven driver-only most of the time.  Does the same situation exist with the 4A?  Is one rear spring longer than the other to provide the ride height difference?  Have you tried measuring the ride height with someone (an adult, preferably) in the driver's seat?

Mike

Cell:  630-202-0065

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of Michael Marr
Sent: Tuesday, March 23, 2021 8:03 PM
To: Jim Henningsen <[email-masked]>; [email-masked]
Subject: Re: [TR] TR4A IRS Suspension Question

Mike

Cell:  630-202-0065

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of Jim Henningsen
Sent: Tuesday, March 23, 2021 7:06 PM
To: [email-masked]
Subject: [TR] TR4A IRS Suspension Question

Any help appreciated.   

Thanks
Jim Henningsen
Ocala FL

Archive: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.team.net_pipermail_triumphs&d=DwICAg&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=HL4LAX-jeuoWNeqz1u1ryqDHfrhQ38xO3ECYGpjCniQ&m=__H5yZGKgEot106jXrnK0ayVFqHx8VmwcHd8FbB_ZnU&s=ZNGZmag_uY1qOR3qgS5U1rbWEBmcJ0B1_REwF5XXuqw&e=  https://urldefense.proofpoint.com/v2/url?u=http-3A__www.team.net_archive&d=DwICAg&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=HL4LAX-jeuoWNeqz1u1ryqDHfrhQ38xO3ECYGpjCniQ&m=__H5yZGKgEot106jXrnK0ayVFqHx8VmwcHd8FbB_ZnU&s=ronelEv9Ia-pr3sYl7XP_M4OYoXg4OZrI2rA30uien0&e=

---

From: "Jerry Van Vlack" <[email-masked]>
Date: Wed, 24 Mar 2021 11:33:03 -0400

Jim, I did the same modification (or nearly the same) on my 4A a few years 
ago. 1" lower all around but HD lever shocks and Goodparts rear trailing arm 
adjustable frame brackets.

Lowering the 1' will cause issues with your alignment shop as it relates to 
getting some negative camber for the front and perhaps the rear too since 
you did not install the adjustable brackets in the rear which are adjustable 
for camber.

The front is a bit more difficult in that you'll need the ability to adjust 
the upper A arms since (at least in my case) removing all of the shims on 
the lower A arms still did not pull the bottom in enough to get the negative 
camber I wanted. I was after 1/2 to 1 degree of negative camber. You don't 
want positive camber. There are consumer available parts to make the upper 
arms adjustable from a few of the British suppliers in England. I suspect 
you'll need to source those. Not sure why the big 3 here in the states don't 
offer something for the uppers.

As to ride height differences in the front it may take some driving to 
settle the front. The rear may or may not be affected by the tube shocks if 
they bottom out at rest (very unlikely and not wanted) The Goodparts 
brackets can adjust ride height while maintaining a good camber setting so 
I'd recommend installing those as well as some form of front upper A arm 
adjusters before spending cash with an alignment shop.

Others may have differing opinions but this was my experience and solution 
when lowering the 1" all around.

JVV

-----Original Message----- 
From: Jim Henningsen
Sent: Tuesday, March 23, 2021 8:06 PM
To: [email-masked]
Subject: [TR] TR4A IRS Suspension Question

Ok, just finished redoing front and rear suspension on my 67 4A IRS.
Complete disassembly, clean, repaint, new urethane bushings, tie rod ends,
trunnions, etc.  New comp springs ( 1 inch lower) all corners, new stock
tubes shocks up front and new KYB gas shocks on the tube shock conversion
brackets for the IRS.  Reinstalled all alignment shims as installed as the
car drove pretty straight.  Urethane packings on springs.

After completing, I noticed that all four corners have a slightly different
ride height when measured from garage floor to bottom on fender lip at
center of each wheel.  Left front: 26 3/4 inches, Right front: 26 1/4, Left
rear: 27 3/8, right rear: 27 7/8.  I think the higher rear height is coming
from the tube shock conversion as it was lower with the levers.    So about
a half inch off each side.   I don't recall having this issue when I redid
my TR6, but that was a while ago.   Rears also have stock trailing arm
brackets (one and two notch brackets on each side - believe these are
original from new given history of the car).

Looking for help on next steps before bringing it in for an alignment.  Will
alignment correct height difference or do I need to add 1/2 inch spacers on
lower sides.  I am going to put uprated valved levers back on rear to
eliminate the extra height in rear.

Any help appreciated.

Thanks
Jim Henningsen
Ocala FL

http://autox.team.net/mailman/options/triumphs/[email-masked]

---

From: "dave" <[email-masked]>
Date: Wed, 24 Mar 2021 11:26:05 -0500

+1 on the Goodparts adjustable camber brackets

-----Original Message-----
From: Triumphs <[email-masked]> On Behalf Of Jerry Van
Vlack
Sent: Wednesday, March 24, 2021 10:33 AM
To: Jim Henningsen <[email-masked]>; [email-masked]
Subject: Re: [TR] TR4A IRS Suspension Question

JVV

-----Original Message-----
From: Jim Henningsen
Sent: Tuesday, March 23, 2021 8:06 PM
To: [email-masked]
Subject: [TR] TR4A IRS Suspension Question

Any help appreciated.

Thanks
Jim Henningsen
Ocala FL

http://autox.team.net/mailman/options/triumphs/[email-masked]