Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Toe out

I was doing some maintenance today, and with the front end jacked up, thought I would try and measure the toe of the wheels. I took my reference from the same outer tread on each tyre. At 9 o'clock position towards the front of the tyre there was a difference of 0.5 inch to the distance at 5 o'clock towards the rear. From these measurements, it would put it at toe out. The handbook recommends up to 3.2mm toe in. My question is, would being jacked up effect the toe reading? I'll take it for an allingment check anyway, but just wanted people's thoughts.

If the track rods from rack hang down a little when car jacked up it would tend to pull the steering arms together slightly, increasing toe in. If your measurements are correct the actual toe out, correctly measured again with suspension loaded (static), may be worse!

Suggest having tracking laser checked and corrected. The 3.2mm or ⅛" toe in is collective between wheels so each should face inwards half that amount with steering wheel in straight ahead position.

Make sure the engineer loosens inner (LHT) and outer (RHT) locknuts and twists rods to adjust each side. I found one of my track rod ends at a noticeable angle from horizontal, probably because only inner had been loosened to adjust. This has left TRE dust seal cracked!

Had another measure this morning with the wheels on the ground. Measured distances between 7 o'clock and 5 o'clock positions and there was a slight toe in, so when jacked there is quite a bit of movement.

Toe should be measured 3 and 9 o'clock surely. Camber 12 and 6.

If your Morgan is driving normally (for a Morgan) what caused you to think of checking the tracking..?

With well greased king pins, if it maintains a straight ahead course with hands off the wheel in a smoothly surfaced car park or similar, and on the road does not try to dart off to the left or right when hitting bumps or repairs in the road, and the steering wheel self centres after a turn... what`s more to want..?

As for perfect alignment... if the tyres are not showing uneven wear patterns such as scrubbing, then all told I might suspect you had little to be concerned about..?

On my old+8 I have witness marks on the exhaust pipes behind the rear wheels where tyre contact seems to be made on occasion, it is as if someone may have caused the rear suspension to allow the axle to deflect a tad when cornering enthusiastically, but then it is a Morgan and I suspect there may be a fair bit of chassis and frame flexing going on, thus seeking to create or maintain exactitudes may keep you busy...

I once inadvertently swapped the front wheels over, having had all four wheels off during maintenance and the steering felt a little different, though the tyres had no obvious sign of scrubbing of any sort.. I left them on and after a few miles everything felt back to normal... Perhaps they did not like rotating in the opposite direction..?

Just thinking in type.

Isn't what you're seeing bump steer? .... but as lifting the car causes droop on both sides at once it presents as changing toe.

If so, it's a fundamental of the design of the steering geometry (though it could be dialled out by modifying steering pickup points if you were desperate for an annoying job to do).... I presume on the road it's fairly minor and lost in all the other idiosyncrasies of the pre-war front end 🙂

K

The bump steer on a trad Morgan is shocking
The best you can do (on a R&P car) is have the track rods perpendicular to the kingpins at ride height

I suspect the "problem" with Trad steering may be associated to the expectation of ageing drivers and others who have become well used to the evolution in the form comforts and engineering design that they have become well used to in their everyday transport and then use that as a datum to compare their Trad against..?

When I bought into the idea of a Morgan, my thinking was to enjoy a degree of a vintage driving experience without the high cost of a real 100mph plus Vintage vehicle, and in that respect my Trad Morgan+8 did not disappoint...

I had just wondered, after reading up a whole back about the effects of steering and suspension geometry, whether my tracking my be out due to suffering a bit of "wheel shimmy". After installing some bearings under the main spring and removing the damper blades I expected the shimmy to go, but it's still there. Only noticeable on spirited driving, or where road surface is quite uneven. I'll look out for the things you suggest.

Isn't the bump steer mitigated to a large degree by having the track rods as long as possible Simon? This allowed by having them connected to centre of rack rather than each end as with M3W for example, which did suffer from serious bump steer at its outset.