[TR] TR4A IRS Suspension Question

[John Macartney]

Someone speculated earlier today that suspension settings may have been adjusted when the car was in build at the factory to compensate for driver weight? Not so, I’m afraid. How do you compensate for a left or right weight bias when you don’t know in advance what that weight would be? When the cars were new and going through the water test and on the rolling road at the end of Final Finish, it was clear for everyone to see that one side of the sat lower than the other as long as someone was in it. Over time, and especially on cars of Herald or Herald derivative suspension type, the stance always adopted a marginal sag on whichever side the driver sat. That was the price you paid for such outstanding engineering:)

Jonmac

Vote for Guy Fawkes! The only man who entered Parliament with honest intentions.

> On 25 Mar 2021, at 02:22, Sujit Roy <triumphstag at gmail.com> wrote:
> 
> Can the engine rotation cause one side to lean more. I've heard that about Stags
> 
>> On Wed, Mar 24, 2021, 7:14 PM David Brady <dmb993 at earthlink.net> wrote:
>> When you figure this out, please let us know. I've had the same question about my TR250. In my case the steer and drive axles on the right hand side are quarter inch or so higher than the left. Correct or not, I attribute this to these cars being setup as RHD and Triumph tweaking the right side slightly higher to attribute for pilot weight. Of course, this doesn't help things on this side of the pond.
>> 
>> David Brady
>> '68 TR250
>> CD8124L
>> 
>> -----Original Message-----
>> >From: Jim Henningsen <trguy75 at gmail.com>
>> >Sent: Mar 23, 2021 8:06 PM
>> >To: triumphs at autox.team.net
>> >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
>> >
>> >** triumphs at autox.team.net **
>> >
>> >Donate: http://www.team.net/donate.html
>> >Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archive
>> >
>> >Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/dmb993@earthlink.net
>> ** triumphs at autox.team.net **
>> 
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archive
>> 
>> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/triumphstag@gmail.com
> ** triumphs at autox.team.net **
> 
> Donate: http://www.team.net/donate.html
> Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archive
> 
> Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/john.macartney@ukpips.org.uk
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/triumphs/attachments/20210325/932435d5/attachment.htm>