Jim is absolutely correct, there is a typo on the list. It should read 3D
2D, NOT 3D 2U at the 0.98 angle.
I've republished a corrected version of the original posting below. I've
double checked the 36 combinations against my original data and the list is
now correct. Hopefully, this hasn't caused too much frustration from those
who might have used the old, incorrect list at that camber angle.
Brian Lanoway
73 TR6 CF6985U
Winnipeg, Canada
Here's the original posting:
Subject: TR6 rear camber adjustment - long
Date: Thursday, August 27, 1998 12:49 PM
It's now taken me 2 years, but I finally think that I've got the camber
on both my rear wheels right and I thought the list might benefit from
some of the 'science' I've applied to the task. There's been some
traffic on the list last spring about this subject, but I haven't seen a
comprehensive approach to this yet. I hope this helps.
First some background. Last year, I installed new trailing arm up-rated
rubber bushings, springs and rubber spring packings, only to find that
the rear camber was still excessive - with the driver's side sagging
more than the other. This spring, I mixed and matched the trailing arm
brackets - using the same mirror-image combination on both sides - the
net result being the proper camber on the passenger side with some sag
still remaining on the driver's side. Finally, I remixed the brackets
on the driver's side alone to get that right. I now have both sides at
the proper camber angle - primarily through using various trailing arm
bracket combinations.
Since there are 36 possible trailing arm bracket combinations with the
one notch, two notch and three notch brackets - either in the 'up' or
'down' positions, I measured the bracket and trailing arm geometry,
applied some trigonometry, and then created the following table to
determine the range of camber adjustment possible using the 36
combinations. Please note that the camber angle shown in the table is
the RELATIVE angle between bracket combinations, the actual angle you'll
end up with depends on the camber angle you're starting with. Also note
that the negative camber angle DECREASES as you go down the table.
By the way, 3U means positioning the bracket with the three notches up,
etc.
Here's the table:
outer bracket - inner bracket - relative camber angle (degrees)
3D - 3U - 0.00
3D - 2D - 0.98 (was previously published in error as 3D 2U)
2U - 3U - 1.50
3D - 1U - 2.11
1D - 3U - 2.42
2U - 2D - 2.49
1D - 2D - 3.40
3D - 1D - 3.49
2U - 1U - 3.61
1U - 3U - 3.80
3D - 2U - 4.40
1D - 1U - 4.53
1U - 2D - 4.78
2D - 3U - 4.93
2U - 1D - 4.99
3U - 3U - 5.91
2D - 2D - 5.91
1U - 1U - 5.91
1D - 1D - 5.91
2U - 2U - 5.91
3D - 3D - 5.91
1D - 2U - 6.83
3U - 2D - 6.89
2D - 1U - 7.04
1U - 1D - 7.29
2U - 3D - 7.42
3U - 1U - 8.02
1U - 2U - 8.21
1D - 3D - 8.33
2D - 1D - 8.42
2D - 2U - 9.33
3U - 1D - 9.40
1U - 3D - 9.71
3U - 2U - 10.32
2D - 3D - 10.84
3U - 3D - 11.82
The actual angle you achieve may differ somewhat from that listed above
because the rubber bushings distort when you force the bushing bolts
through to meet the new bracket holes.
I found that it's best to change only one bracket per trailing arm at a
time. If you want to leave the ride height alone, change the inner
bracket. If you want to raise (or lower) the ride height while changing
the camber angle, change the outer one. To use the table, figure out
which bracket you're going to leave as is and then find the next
combination that allows you to do this while achieving the approximate
camber angle change desired.
In my particular case, the combination I ended up with was: passenger
side; outer = 1D inner = 2U, driver's side; outer = 3D inner = 2U.
I should point out that it is very possible to change out a bracket
while leaving the rest of the rear suspension intact. To do this, place
the rear of your TR on jack stands, jack up the trailing arm so that you
can support it (and take the spring pressure) with a secure support
under the trailing arm, place your jack under the arm where it joins the
bracket, remove the bushing bolt, remove the nuts on the bracket to
frame bolts, raise or lower the jack so you can get the frame bolts out,
remove the bracket and install the new one. Make sure you replace the
alignment shims as you found them. There is some grunt work involved in
getting the trailing arm back into the new bracket and aligning the
bushing bolt holes (I've found that a pipe clamp is a great help in
forcing the trailing arm back into the bracket) but the whole job can be
accomplished in about an hour and a half.
Couple of cautions: make sure the trailing arm is securely supported
while you do this; that rear spring can cause a severe injury if it lets
go. Secondly, go this bracket change-out route only after you've
renewed the trailing arm bushings, springs and packings as required.
-----Original Message-----
From: Jim Hill [mailto:Jim_Hill@chsra.wisc.edu]
<mailto:[mailto:Jim_Hill@chsra.wisc.edu]>
Sent: Friday, May 25, 2001 1:12 PM
To: 'Lanoway, Brian'
Cc: 'triumphs@autox.team.net'
Subject: RE: TR-6 and Negative Camber
Brian Lanoway, author of what must certainly be the most-saved single
document in list history (and certainly one of the most valuable), wrote:
>For those of you who are interested, my original camber
>article is posted in Bob Kohout's TR web site:
>http://members.visi.net/~kohout/contents.html
Anyone who doesn't have a copy of Brian's camber chart for trailing arm
brackets should print it out and bookmark the source - you'll need it sooner
or later.
There is one small error in the chart (a typo I expect): The "3D - 2U"
bracket combination appears twice in the list, once as a relative camber
angle of 0.98 and again at 4.40. I believe that the latter angle (4.40) is
correct for the "3D - 2U" combination, and the bracket configuration for
0.98 should be changed to "3D - 2D" (it's the second combination listed on
the chart).
Thanks again for creating the chart and making it available Brian.
Jim Hill
Madison WI
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