Wheel alignment

[John McCormack]

I'm not happy with the wheel alignment on one of the TR2s. It has a bit of negative caster on both front wheels, a bit more -ve on the left. It also has a small amount of -ve camber on one front wheel.

I recall hearing that there is a mod that allows adjustment of caster and camber. Is this the case and where can I get the bits I need?

Is there anything else I can do to change caster and camber?

[Hamish]

John

stand to be corrected. But I thought that the caster was  set by the trunnion. 
unless there is something else out of alignment (or bent) the later 4a onwards had 3 degree pos.

the camber can be adjusted at the fulcrum . 
there is a fulcrum kit to do this typically people move to later TR4a top wishbones and ball joint.

However @Drewmotty on here designed a lovely and subtle blocks or plates to move the fulcrum for camber.

H

 

Edited June 29, 2021 by Hamish

[RogerH]

4 hours ago, John McCormack said:

I'm not happy with the wheel alignment on one of the TR2s. It has a bit of negative caster on both front wheels, a bit more -ve on the left. It also has a small amount of -ve camber on one front wheel.

I recall hearing that there is a mod that allows adjustment of caster and camber. Is this the case and where can I get the bits I need?

Is there anything else I can do to change caster and camber?

Hi John,

it is the TRunion that affects the caster.  The TRunion for the TR2 (& 3-4) is 0 degrees.

If the 4A-6 TRunion is fitted (3 degrees)  then there will be a whole lot more going on - so easy to see if it is original.

Roger

[Lebro]

Almost right !   the castor is set by the trunnion type, & the upper wishbones. TR2 - early TR4 had 0° castor, later cars had 3° castor.

Camber is set by the upper fulcrum, & upper wishbones.  it can be altered by lengthening or shortening the wishbones, or substituting a different upper fulcrum.

Revington's (& Bastuk) do an adjustable one (pain in the Ar$e to set up) Andrew (Drewmonty) designed a fixed one to give a small amount of -ve camber.

Bob

Edited June 29, 2021 by Lebro

[John McCormack]

19 minutes ago, RogerH said:

Hi John,

it is the TRunion that affects the caster.  The TRunion for the TR2 (& 3-4) is 0 degrees.

If the 4A-6 TRunion is fitted (3 degrees)  then there will be a whole lot more going on - so easy to see if it is original.

Roger

Thanks gents. 

The chassis for this car had no sign of any damage or repair, but for some reason I have 1.4 deg -ve caster on the left wheel and 0.5 deg  -ve on the right. Camber is -ve 0.6 deg on the right wheel. Left wheel camber is correct. Without the spring I can lift the wheel through its full range on both sides. It is stiff but it has new bushes all round and Superpro ones on the top.

The car actually drives ok, the local Triumph specialist had to have the issue pointed out before he noticed it when driving.

But because my other TR2 steering alignment is spot on I can feel the difference.

I am wondering if I have put it together incorrectly. The suspension components aren't handed so I can't see how I could have done it incorrectly. It isn't the first suspension I've done over the past 45 years.

If I use the TR4A upper wishbones would that solve my caster?

 

Edited June 29, 2021 by John McCormack

[Lebro]

You can't use the later upper wishbones without changing the trunnions to late TR4 ones. you would also need to change the upper ball joints.

Your TR2 should have 0° castor, & +2° camber. if it is different then:

1) the chassis / suspension parts are damaged, & mis-shapen

2) Some one before you has fitted different parts to the suspension

3) The measurements are wrong.

 

Bob.

[stuart]

14 minutes ago, John McCormack said:

Thanks gents. 

The chassis for this car had no sign of any damage or repair, but for some reason I have 1.4 deg -ve caster on the left wheel and 0.5 deg  -ve on the right. Camber is -ve 0.6 deg on the right wheel. Left wheel camber is correct. Without the spring I can lift the wheel through its full range on both sides. It is stiff but it has new bushes all round and Superpro ones on the top.

The car actually drives ok, the local Triumph specialist had to have the issue pointed out before he noticed it when driving.

But because my other TR2 steering alignment is spot on I can feel the difference.

I am wondering if I have put it together incorrectly. The suspension components aren't handed so I can't see how I could have done it incorrectly. It isn't the first suspension I've done over the past 45 years.

If I use the TR4A upper wishbones would that solve my caster?

 

If you use the 4a upper wishbones you will need to use the 3 degree trunnions and vertical links. Bob beat me too it there!

Whole different ball game. Its very difficult to measure on a built car as the engine is in the way but essentially the distances between the front and rear  mounting points of the upper wishbone inner bracket and the front and rear mounting points of the lower inner wishbone mounts should all be equal and at dead right angles to each other. Its the first thing I measure when restoring a chassis. Early chassis are very prone to bending of turrets etc even with just something simple like a hard kerbing.

Stuart.

[Lebro]

No need to change the vertical links, just the upper wishbones, ball joint, & trunnions.

By the way Moss can supply special vertical links which will give you -ve castor angle without changing anything else, but won't change the castor angle.

Bob.

Edited June 29, 2021 by Lebro

[BlueTR3A-5EKT]

53 minutes ago, Lebro said:

No need to change the vertical links, just the upper wishbones, ball joint, & trunnions.

By the way Moss can supply special vertical links which will give you -ve castor angle without changing anything else, but won't change the castor angle.

Bob.

That is what are on my car with the TR4 trunions etc.

Is it possible you have bent wishbones?

Peter W

[david ferry]

John,

Do you really have negative caster? This would mean the vertical links are leaning forwards at their upper end. If you do, the steering will be very light indeed and 'wobbly' to the point of being rather horrible.

What you want is positive caster, or at worst zero. Vertical links leaning backwards at their upper end, or vertical.

There's been a variety of comments concerning TR4a onwards components. It's worth remembering that early TR4 front suspension is the same as on a side screen car, the changes being made later on in TR4 production so that there was caster introduced to the set-up. This was by means of different upper wishbone arms, ball joint design/arrangement and trunnion. Side screen cars, earlier and later TR4 vertical links are the same. 4a onwards vertical links are handed, as are the trunnions so won't help you. The 4a onwards trunnions do not have the fixed pin through them, there's a big bolt that goes through them, and the lower wishbone arms. Lower wishbone arms from 4a onwards are different too.

Some of the 4a onwards parts are the same as later TR4 parts, but I'd recommend sticking with looking at later TR4 parts to be certain not to get the wrong/incompatible parts.

David

[John McCormack]

All very good advice, thank you.  Bob's comment re the measurements being correct has alerted me to that possibility.

From what I have read -ve caster makes the car very difficult to steer, especially at speed. I've had this car over 80mph and regularly drive at 70mph on the freeways. It seemed to steer ok, I have no trouble holding a steady line in a lane and it doesn't noticeably pull left. When the wheel is let go the car has a very slight drift to the left which is pretty normal with road camber to the left.

The car handles ok when I give it a nudge on winding roads, not as good as my other TR2 but that one has bigger tyres and 60 spoke wheels versus the narrower 48 spokers on this car.

The effect on the steering that annoys me is that when driving there is a bit more effort required to turn the steering wheel to the right than to the left. A bit more resistance to turn the wheel to the right you could say. I put this down to the left wheel having more -ve caster than the right. The difference isn't there with the wheels off the ground.

Maybe the measurements aren't correct (i.e. the left wheel has less +ve caster than the right but not as -ve as the measurements indicate) and I am looking for a problem that isn't there.

 

Edited June 30, 2021 by John McCormack

[Z320]

Hi there,

I've the upper construction thread adjustable by one of the more sportive TR parts suppliers.

But I forgot their name, I remember a green / yellow (?) illustration of a Small mouth (?) as logo on their website.

I hope I'm right......

Ciao Marco

[Z320]

this is the offer, not ask me what else has the be changed

[John McCormack]

37 minutes ago, Z320 said:

Hi there,

I've the upper construction thread adjustable by one of the more sportive TR parts suppliers.

But I forgot their name, I remember a green / yellow (?) illustration of a Small mouth (?) as logo on their website.

I hope I'm right......

Ciao Marco

Thanks Marco. I have asked Racetorations if these parts also allow caster adjustment. Cheers John

Edited June 30, 2021 by John McCormack

[Z320]

The caster cannot be adjustable,

in my opionion you need wishbones and trunnions suitable 0 deg. or the hole stuff 3 deg.

[stuart]

58 minutes ago, Z320 said:

The caster cannot be adjustable,

in my opionion you need wishbones and trunnions suitable 0 deg. or the hole stuff 3 deg.

Actually with those Racetorations upper arms where they use the later type top ball joint it is possible to very slightly shim them to give a small adjustment of caster if you use the rest of the later 4a/5/6  set up.

Stuart.

Edited June 30, 2021 by stuart

[roy53]

I would guess at bent uprights being your issue.  Try swopping to another and see if any difference, if yes then you know.

Roy