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TR4/4A 62 TR4 alignment specs

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SCguy

SCguy

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I got my TR4 to the the alignment shop today. Here's what they found and did.

Front
Toe set at 1/16" <span style="color: #009900">(toe in is the only adjustment that can be made)</span>
left camber is +1.94 right camber is +1.07
left castor is +0.03 right castor is +0.50

Rear
left camber -0.25 right camber -0.25
left toe -0.14 right toe +0.22

So my question... What do I worry about? What do I fix and how? My take is that things are sort of OK for a 30+ year old car that has been off the road for 15 years. Am I right?
 
I need to learn a little more about alignment and before this disappears into obscurity I was wondering myself if anyone knows.

If I'm reading this right the rear tires are angled inward a tiny bit and pointin slightly in different directions (one in and one out?). While the front tires are angled outward a tiny bit which is good but they are not the same so one is angled out more than the other? Toe in is at 1/16ths spec. and good. Front castor is in the positive and this is with-in the good range? Or is some shimming required to get them both at .50? My guess is the numbers are minimal? What did the alignment shop say other than to rotate the tires frequently?
 
Your understanding is basically correct, Harry. Since the rear toe measurements have opposite signs, it means that the wheels are nearly parallel, but not perfectly aligned with the center of the car. At any rate, they are close enough. FWIW, I have a healthy distrust of 'computer' alignment, since those fancy readouts to .01 degree tend to obscure the fact the measurements are only as good as the technician's setup and the machine's condition. On most cars, there is more play in the bearings than that !

I didn't have time to find my TR4 manual last night, but I think an early TR4 should have the same alignment specs as a TR3, meaning 2 degrees of camber (front wheels tip out at the top). Since there is no adjustment, but wear tends to lower the camber, I would look for worn components on Larry's right front.

Caster is supposed to be zero (again for TR3/early TR4. Later TR4s had 3 degrees of caster). The 1/2 degree of castor on the right would also tend to indicate there is something wrong at that wheel (most likely the rear upper inner bushing, IMO). Of course, the alignment shop should have looked for any problems, but my experience is that they pay no attention unless they think they can get more of your money.

Later Triumphs did have places to shim to adjust castor and camber (including the rear wheels on IRS models) but the TR3/4 don't. There are ways to add adjustments, but the factory didn't give us any.
 
Hmmm ... are you sure the upper arms are assembled properly ? They aren't mirror images as you might think; on the RH side the front arm goes closest to the ball joint, while on the LH side the rear arm goes closest to the ball joint.

One degree of camber and 1/2 caster isn't really a lot, so as long as it drives OK you could probably just ignore the issue.

Did the pivots all look good (not bent) when you replaced the bushings ? Did that include new trunnions and the outer, lower bushings (brass in steel) ?
 
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