Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Tracking 3.7l Roadster

I'm getting new front tyres for Belle on Tuesday.
Does anyone know the tracking settings please?

MMC just said a slight toe in on 3mm

For the S1 Roadster (so an earlier car) GoMog has from the dealer details
Front Wheel Alignment and Suspension
205/60 15 or 205/55 16 tyres
Castor angle 4°

Camber 0.5° NEG + 0.5°

Kingpin inclination 2°

Toe-in 0 to 3.2mm)

I've always worked on between 1/16" and 1/8", which according to my convertor is 1.58mm t0 3.175mm.

MMC god bless them did say 1/8th which they thought was close to 3mm. Thanks Dave.

My local tyre shop with their laser equipment worked in degrees so 0.5° total toe in, half that each side. Factory quote in handbook 0 to 3.2mm (⅛") total. I don't feel the car would have enough hands off stability with zero though.

FWIW my car was found to have toe out ex factory!

BTW whilst your at it might be worth checking camber as well John. I have a magnetic thingy that attaches to discs if you want to borrow. Again I found one side with a little too much. Handbook 0.5° negative.

Thanks Richard. There is nothing in my handbook

Mark B at MMC told me these settings for my 3.7...

Camber, 0.5 deg negative (max)
Castor, don't get involved in this unless racing & you own a gas axe
Tracking, 3mm toe in (total of both sides)

Extra bits from my personal book of frustration & errors...

Be very careful measuring Camber because if the wheels are even a tiny bit off the dead ahead then the kingpin Castor inclination will bu66er up the reading - you'll be convinced one side is -neg, the other +pos using a mag gauge stuck to the disc

Oh, and because most Mogs are built on the pi55 (inaccurate chassis) all the above is a waste of time unless you set up on a 4 wheel laser jig and make sure the rear to front is parallel

Cheers

With car on ramp I took a metre long spirit level and checked bottom cross arm for level. It needed about an ⅛" under lifting pads on one side to achieve this, provided by some old coasters. This took account of any chassis/frame error - I think

I then set steering wheel straight ahead having previously checked it did drive straight in that position.

Using spirit level and try square I calibrated the magnetic camber device to ensure it read zero = horizontal when clamped to a perfectly vertical surface. After clamping device to top of disc with kingpin fixings loosened I checked/adjusted camber. After re-tightening kingpin fixings I re-checked. Hopefully that covered all the bases

I think cooperman is spot on!

The chassis is so Chinese in style that it's an approximation. However I did want to see if the inclination for the camber angle's were the same. I found that when the car was on the lift, using a 600mm level with one adjustable vertical vial for degrees let me assess if both sides were equal. Like richardv6 I levelled the crosshead then asked my wife to control the steering wheel until one wheel showed as perfectly vertical on the fixed vial (so steering slightly out of the straight ahead position). I then went around to the other wheel and set the adjustable vial to show vertical. Staying on that side I got my wife to move the wheel back to show vertical on the fixed vial and holding the steering in that position I returned to the first wheel and checked to see if the adjustable vial was equal to the other sides setting. This won't show the camber angles as an accurate reading, rather that both sides are the same or otherwise! My car is just pre. the adjustable setting system for camber so really there is not a great deal I can do without great effort and cost. This is fundamentally a steering geometry test/check and is using the castor angle to change the camber angle for measurement.

A simple gauge can easily be constructed using a sliding joint which allows you to read the difference between the mid point front and rear rim measurements for tracking adjustment and 2-3mm is fine here (tow-in). The car is so light that unless the tracking is miles out you won't tend to get scrubbing to the edges of the tyre's very quickly . If anyone is unsure of tow, whether it should be in or out a general rule of thumb is rear wheel drive is tow-in and front wheel drive tow out.
on these often low milers if you find you have stunning self centering steering you have probably got too much toe-in and if a bit hard to steer into a corner and hold a line It'll be toe out excess and you will feel the outside wheel scrubbing and pulling against the chosen steering line the car is taking.

If you have an awful car that just does not seem to drive well then a thorough chassis and steering geometry check is required. If all looks well don't forget rear axle positioning and if you are happy with that a four wheel track is a good starting point. As such the rear tracking is not adjustable, as are modern cars but it's possible to get all the wheels traveling in the same direction!

Your thoughts seem very intuitive Sewin regarding toe out reducing steering response and toe in improving it. In actual fact though it's the exact opposite, ask any racer. I quote this response on the subject which better explains than I can.

With toe out, if you were to turn right, the inside wheels would actually turn in more and the outside wheels would actually straighten up more and would fling the car round the corner, increasing turning ability and decreasing understeer. Though on the straights, it's a lot more unstable than toe in because it can cause the car to twitch left and right. Toe in is the exact opposite of what I said

I have personal proof of this. After fitting the SSL RS dual rate conversion I naturally took the car for a thrash round the local lanes. The improved turn in allied to comfort was immediately apparent as I chucked the car left and right. Later on though, whilst still being sensitive to the changes I had made, on a straight road I perceived a slight wandering. This prompted me to have the tracking laser checked and adjusted. Not too surprised to hear that toe out was found before correction, cannot remember how much but it was more than the ideal toe in.