Steering becomes hard to turn when dash gets hot

[andyhay]

Hi All

I have a very strange niggle with my car. When the car is parked in the sun and the dash and steering column cover get hot (Australia - so they do get hot) the wheel becomes very difficult to turn. It becomes very unpleasant to drive and I have to really wrestle with it. As the steering column cover cools down the problem goes away. Could it be the upper bushing becoming sticky as it gets hot?

The issue only occurs after the car interior has heated up - can drive on a 38 degree day with no symptoms, its only after direct sun hits the dash and steering column.

The car is a 1968 Elan +2 with the older non collapsible steering column.

Any ideas?

Thanks

Andy

[2tmike]

Outside chance, direct sun on steering wheel spokes warming the inner column up and expanding it a little...but then its quite a chunk of steel to heat up so a fair size heat sink....

[JonB]

Maybe try some insulation round the bush location. Just a bit of foam wrapped round it. Experimenting might help narrow the cause down.

Is there any noise when it?s tight? I?m thinking that the steering wheel could be fouling the column housing slightly.

Here in the UK it?s been raining more or less constantly for weeks. Mind you, I wouldn?t like to drive a Plus 2 in the Aussie heat. It?s bad enough in our mild summers! Have you got A/C?

[Hawksfield]

Hi
A dose of WD 40 down the steering column via the indicator switch for an immediate solution.
any further problems would require shaft removal

Good luck

[Jentwistle3]

WD-40 is a crappy lubricant. Get yourself some Gibbs Oil

[2cams70]

That sounds weird! Suggest hitting it with freeze spray in specific areas to try and isolate where the problem is.

https://www.jaycar.com.au/freezing-spray-can/p/NA1000

[Donels]

I suspect you were close first time. The nylon bushes in the steering column are a close fit. If the outside temperature is 38 C, and sitting in the sun I guess internal temperatures could get 10 - 12 C hotter or more. Coefficient of expansion for nylon is about 100 and for steel its about 10, so the clearance between bush and steering shaft could be zero, with the bush binding the steering shaft. Once it cools the clearance is back and it frees off. The simple solution is a sun shade in the screen I would suggest.

[Chrispy]

No trouble with my 67 +2 in Brissie.

I got sick of the heat and put in AC though!

[2tmike]

Relative expansion of the bush and inner column works in the opposite way that might be expected.... The column od gets a bit bigger with temperature but the hole in the bush also gets bigger and because of the difference in expansion coefficients between steel and plastic the increase in column diameter is less than the increase in the hole diameter so the gap increases ....it's one of those things that's counterintuitive but wins a few bets:)))
If it is an expansion effect it needs the inner column to see more temperature than the bush which really means heat transmitted from the wheel or the rack.
Perhaps the original idea of the bush just getting sticky when warm is right and wd40 the answer....unless there's any snake oil left.....

[andyhay]

Thanks all for the suggestions. Sounds like the first thing to try is getting some lubrication on the upper bush.

I like the idea of using the freeze spray to narrow down the problem. As an aside there is absolutely no play in the steering column - doesn't even wiggle a bit so the bushes are obviously a tight fit.
I'll give lubrication a try and report back. I have WD40, Silicon spray and singer machine oil at hand - which would be the safest bet?

Regards

Andy

[snowyelan]

I guess I'll throw my 2 cents in here. I agree the column and shaft expand at the same rate and the gap between the 2 will increase. However what will decrease is the gap between the bush and shaft due to the different coefficient of thermal expansion rates (10 to 1 noted above). The nylon can't expand beyond the ID of the column because it's the weaker material so it expands into the only place left, the clearance to the shaft.

[oldelanman]

For cars fitted with the Triumph column ...

The original Metalastic column bush has a split nylon inner sleeve inside a rubber outer body so I think it unlikely that any thermal expansion would cause the shaft to bind. Replacement bushes that I have seen have a longer nylon inner sleeve without a split so are perhaps more likely to give problems with thermal expansion. In either case if the bush is not fitted correctly, with the rubber lugs located in the holes in the outer column, the column is likely to be a tight fit through them. I would check that both upper and lower bushes are installed correctly before trying anything else.

Lower bush locating lug

Upper bush locating lug

Edit:-
This info will not apply to cars fitted with the Ford column .. see Brian's post below.

[ncm]

The car is a 1968 Elan +2 with the older non collapsible steering column.

Early +2 column is Ford based and uses felt bushes like these https://www.smallfordspares.co.uk/produ ... -felt-bush , not the Triumph rubber/nylon items being discussed above.These were fitted to later cars.
See also parts book in wiki http://www.lotuselan.net/wiki/HB_-_Stee ... olumn_%2B2 (item 4)
Brian.