Strut shims

[johnfrancis898]

I am currently completing a front suspension & steering refurbishment. I have removed, dismantled, cleaned and replaced virtually everything. I removed the struts with the hubs still attached and dismantled them on the bench. On the near side I found 2 thin washers behind the spacer which joins the vertical link to the strut which are identified in the parts book as 4 and 10 thou shims fitted ‘as required’. On the opposite side of the strut there was just a 4 thou washer. The offside was different as it only had the 4 & 10 thou washers behind the spacer and nothing on the other side. Is there a rule of thumb for this or is each car unique? I am assuming it’s for steering geometry. I had no problems previously and tyre wear was perfect all round. I have parts arriving this week, new steering rack, struts, so hope to have it all back together next weekend.
Has anyone got any tips or info on this?

[Charles H]

Rule of thumb is to put it back as you found it especially as you sate that the geometry was fine beforehand. You are lucky any are still there! Usually they are not noticed when changing struts and are lost.

[johnfrancis898]

I was quite careful in noting them behind the spacer as they are shown in the parts book but not in the Haynes Manual. I didn’t expect to see one drop out of the other side! Someone has told me they are not supposed to be put behind the spacer. I intend to reassemble as it was. I am getting the wheel alignment done once I have it all back together so will get them to check it. I had new tyres fitted early last year and all the alignment was ok then. The tyre wear has been even all round. I have also been offered a Gunson tool for wheel alignment but not seen one of these before.

[johnnydog]

Hi John,
I have a Gunson wheel tracking tool - a Gunsons Trakrite.
I find it pretty good and have set all my Triumphs tracking with it. It's basically two plates with roller bearings between that allows the top plate to rotate as each front wheel is driven over it in turn. There is a pointer that indicates whether the wheel is rotating in the 'straight ahead' position, giving a 'toe in' or 'toe out' reading, so adjustments to the track can be then made before rechecking and moving to the other front wheel. The beauty if it is that you don't need to know the toe in figure, as the required setting for a moving car is '0', as the moving vehicle has taken up any change in the steering degrees. The static figure of 'toe in or out' has to be used with a static test for this reason.
I think it is important to initially check the front tyre pressures are correct, and to then centralise the steering rack. Although the workshop manual doesn't detail this, remove the grease nipple / small blanking plug, and insert a thin screwdriver or 1/8" drill bit, and slowly rotate the rack to locate a small indentation which then indicates the rack is in its central position, irrespective of wheel steering wheel position as the tracking may have been altered previously. It's worth at this point removing the steering wheel and repositioning it in its straight ahead position as required. This then makes it simpler to do the checks with the trakrite tool as you can see the steering wheel position and easily return the wheels back in the straight ahead position during the checks / adjustment. If the steering wheel isn't straight on the splines it makes it more difficult to carry out these checks.
Having the rack centralised also ensures that the self cancelling position for the indicator stalk is correct.
As with any tracking checks, if the rear end has been dismantled/ replaced/ changed and therefore the original settings may have been altered, then really a four wheel alignment is required. The rear wheel track needs to be correct prior to doing any front wheel alignment; if it isn't, then any amount if adjustment at the front won't get the car running 'straight'. If you've ever followed a car that looks like it is 'crabbing' (the rear wheels aren't following the fronts, usually to one side or the other), then this can be due to the rear wheels not being correctly aligned, which requires the steering to incorrectly compensate for it to the left or right.
If all this makes sense.....?

[Clifford Pope]

The front wheels can only be tracked relative to each other - there is no such thing as an individually tracked front wheel.

But the rear wheels are set individually, relative to the fore/aft line, because of course they cannot steer.
You can set these equally just by looking from the rear and squinting along the tyres and seeing where your line meets the front tyres. Then of course they have to be individually adjusted, equally, so that the toe in or is it out by the correct amount. Finally re-check that each rear wheel points to the same distance from the edges of the front tyres.

[johnnydog]

The front wheels can only be tracked relative to each other - there is no such thing as an individually tracked front wheel.

If the steering wheel is correctly positioned in the straight ahead position once the rack is centralised, and then each front wheel is driven over the Trakrite gauge individually, adjustments can be made to the checked side before moving to the opposite side. Both front wheels can be adjusted this way individually to a Trakrite gauge reading of zero, which is the setting whilst the car is moving (albeit slowly). I have done it this way with mine, and then checked the static settings are correct using the old fashioned cranked bars between the front and rear edges of the wheel rims, which then should give 1/8" toe in reading.
This method does adjust the front track of each wheel individually, but can be adjusted to an equal setting for each.
As a result the cars drive straight, with no pull on the steering, and no questionable tyre wear.
Tracking the rear wheels is a different kettle of fish. The visual method you've outlined is worth doing for a starting point, but I would suggest more accurate checking of the rear wheels, even if only using the string method front to rear as a starting point.
In the 70's whilst on an vehicle examiners course, we were taught the method of using measured fixed bars and string to create an exact parallel box around the car on a level surface (which is important), then measuring the front and rear of each wheel for their toe position relative to the side strings. It's time consuming but can give quite accurate results.

[johnnydog]

There are also shims available to place between the rear shackle and the box section so that the rear track can be adjusted without totally removing the mounting bolts. They are slotted and slide between the shackle and box section after undoing the bolts slightly.

[Clifford Pope]

I don't understand your point. Front tracking is the degree of toe-in or toe-out, of the two wheels relative to each other. One wheel can't have a toe-in. Do Robin Reliants have to have their front wheel tracked?

[johnnydog]

My understanding is that the static wheel alignment setting (when a vehicle is stationary) on our Triumphs is 1/8" toe in. I have used the old cranked bars previously by measuring the difference between the leading edge of the front wheel wheel rims against the corresponding trailing edge of both front wheel rim and altering the track to give 1/8" toe in whilst stationary.
The Trackrite gauge works on a moving wheel - I presume this takes into account any movement of the suspension / steering components and it claims the optimum setting for either front wheel when rolling is 0 degrees or straight, rather than any toe in or out. Therefore the track of each front wheel can be set up independently of each other. It does work - I have used it to set mine up after suspension or steering work, and after the first couple of uses, checked the settings with the bars whilst stationary which showed give or take 1/8" toe in.
This is apparantly why they claim that the manufacturers toe in / out figures are not required if used with a rolling wheel.
If it didnt do as claimed, I'm sure they would have pulled from the market many years ago, but bearing in mind this type of Trakrite gauge has been made for years. I recollect them being used by professional garages in the 90's, long before all the electronic 4 wheel alignment machines such as Hunter and Hawkeye came into being.

The below link may be useful to help understand its principles...

https://youtu.be/X0ytDJ0mJoQ

[Clifford Pope]

I take the point that the wheels should have a zero toe-in when moving, and the usual 1/8" toe-in static setting makes an allowance for the wheels tending to splay slightly when moving, as all the minute play in steering joints and suspension combines to force the wheels outwards very slightly. But it's only an approximation - the actual variation in splay will depend on speed, acceleration or braking, weight in the car altering the suspension height, and of course direction of travel. That's why ideally tracking should be carried out with a normal passenger load and the car should come to a halt for testing in the forwards direction and without sharp braking.

But I still dispute that the two front wheels can have independently adjustable tracking. They are connected by a single solid track rod, or a solid straight-through connection through the steering rack. You alter the tracking by lengthening or shortening that rod. It alters both wheels. Even if you held one of them still so that winding the rod only turned the other wheel, then as soon as you moved off the car would adopt an average course, and the result would have been that you had inevitably adjusted both wheels.

Imagine an extreme example - set one wheel straight ahead and the other at 2" toe-in. Then when you drive a short distance you would find that both wheels were pointing inwards by 1". They turn by caster action and adopt the average compromise position.