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MG Midget and Sprite Technical - Vague Steering
Just wondering if anybody has any advice to give on my 73. I bought the midget over 2 years ago and barely drove it before taking it off the road to put right all the bodges the PO had inflicted on it whilst rebuilding onto a heritage shell. Now, just back on the road for the summer and all is fine apart from the steering going a bit vague and tending to wander slightly around 60 mph. The steering rack is new (refurb), trackrod ends are new and steering column etc all bolted up tight. According to the manual, toe-in should be 0 - 1/16" and I've set it up as near as i can to 1/16". is this correct or should I experiment with different settings? Any ideas as to a solution would be greatly appreciated. Thanks! |
Phim Manship |
checking toe in is easy... I use a long ally pole that gently touches the tyre walls; horizontal, through wheel centre. Typically, on one side it's parallel with the body to the rear, and on the other side it diverges - that way, you know you have a little toe-in. I fitted a new TRE a couple of weeks ago, and have had to adjust toe-in to eliminate wander at speed. (BTW i've had terrible experience with tyre fitters doing tracking with lasers...) Also check the ARB connected OK; tyres at right pressure, and so on. A |
Anthony Cutler |
thoughts: old and under-used tyres tyre pressures faults on or with tyres are all your nuts tight suspension - springs, dampers, bushes rear suspension U-bolts rear axle well out of line toe-in sounds fine ETA: (typing whilst A posted) |
Nigel Atkins |
Thanks for the reply Anthony, excuse the spelling in the first post, couldn't even spell my name correctly! did you have to increase toe-in to cure your "wander" or did you adjust it closer to straight ahead? ... Phil |
Phil Manship |
Hi Nigel, thanks for the reply. Tyres are new all round pressures 22lb? wire wheels hopefully still tight! springs, dampers, bushes, nothing obviously worn or loose but maybe I should re-check. The rear springs are new as are ubolts and rubber mounts, maybe I should re-tighten the u bolts? What would allow the rear axle to get out of line? Thanks again, ..... Phil. |
Phil Manship |
Hi Phil There is a midget and sprite club meeting this weekend in Kent. At the Angel in Addington see events section. I am sure you could pick up loads of good advice there if you are free. |
M Adams |
I've been meaning to get to the Angel meeting for a while now, something always crops up, somebody's bought me tickets to the Crystal Palace Motorsport event this time, next month definitely!!! :-) ..... Phil. |
Phil Manship |
Hi Phil To answer your question toe in will keep the car straighter, giving it parallel or toe out will encourage any wonder. I do however run my car at a tad toe out because this makes the car turn in very sensitive (I love oversteer.) The feeling of wondering of the car is generally when the steering is sensitive thus why toe out gives that impression, however the Midget does have very sensitive steering in normal operation and it maybe this your are experiencing when compared to a larger saloon car. Low pressure in tyres will cause this as will loose u bolts. |
Robert (Bob) Midget Turbo |
Thanks Bob, I guess it is possible that I just need to get used to the sensitivity of the steering but I think i would like to de-sensitise it a little if possible. I'll double check the u-bolts and may be tempted to try a tad more toe-in, just to see if it makes any difference. .... Phil |
Phil Manship |
Bob makes a good point if you've got the full size standrad steering wheel (15.5") and standard width tyres for your wire wheels and you're not use the feel of the car it might be you wandering not the car - regular driving of the car will solve this, and many other things U-bolts should be tight but not He-Man tight rear axle could be out of line because someone put it that way - but don't expext things to be tootally symetrical on these cars as I learnt from other here with modern tyres you can afford to increase the pressure and experiement, I happlily run at +2 psi all round (so 24 psi front) others prefer more ETA: Bob correct me if I'm wrong, more toe in with give more understeer that make the car feel better for some |
Nigel Atkins |
Nigel, thanks for the further input, I've got a 13 inch steering wheel actually, that probably serves to increase the sensitivity I guess and I take your point that it may be me wandering a little. I will re-check the u-bolts though, I probably tightened them around a year ago when fitting the new springs, maybe the rubber mounts have "settled" a bit? I'll also try upping the tyre pressures a bit too. |
Phil Manship |
smaller steering wheel will make turning more direct but possibly less sensitive (if that makes sense and I often don't) yes check the U-bolts even if it's not that it's a good idea to do try increasing type pressure all round at 2 psi increments at a time until you dislike the ride then drop back I settled on 24 front, 26 rear but many things can effect what's best for you on your car for the way you drive many roads to Rome :) |
Nigel Atkins |
Loose U-bolts result in a unique wandering so are easy to detect: Steer straight with the car at steady speed, then put power on, the lift off the accelerator - both without altering the steering wheel. The car steers one way with power on the the other on power off. Loose U-bolts are exacerbated by old hard spring pads, which can be so bad that no amount of tightening will remove the effect. New pads instantly address this and remove the rear end steer at normal tightness on the U-bolt. By the sound of it you fitted new spring pads so this may not be relevant. |
Paul Walbran |
Hi Paul, thanks for that, I doubt that it is loose u-bolts, as you said, I fitted new pads when the new springs went in. I'll check them anyway for peace of mind along with the other thing people have suggested. |
Phil Manship |
I can't do that test it makes my belly wobble which makes the car wobble anyway unless you checked the U-bolts shortly after fitting I bet there's a little movement but as I put before don't take that as they need really tighten up tight when it probably be only one or two that need nipping up, and do each bolt up evenly unless tight the other side I got some NOS in case the U-bolts (or threads?) stretch by I might have been kidding myself, I don't know |
Nigel Atkins |
As Bob says, a little toe-in helps the car feel stable, esp at speed, and is normal for RWD. BTW when the car is being driven, the drag on the front wheels will press against the wheel bearings, bushes etc and tend to straighten the wheels a little. You can measure toe-in (like they attempt to do at tyre shops), or you can make small changes like I do, see the difference with a pole (let the suspension relax first), and feel the difference through the steering wheel / seat. Lack of toe-in can cause the car to follow lorry wheel tracks which can be alarming, as the car appears to jump sideways without warning. A |
Anthony Cutler |
O.K. I thought it was about time I got back to you all with an update on the problems I had. I'm a bit red faced right now because it turned out to be nothing more than tyre pressures which all you helpful people told me all along. The problem was that my pressure gauge was reading erratically, serves me right I guess for using a cheapie. After I got hold of a decent digital gauge I found that the fronts were both low, one was only 17.5lb, my old gauge measured it at 22lb. Tyres correctly inflated, the car handles like a dream, I did over 100 miles yesterday and it was a pleasure to drive. Many thanks to you all for pointing out what should have been obvious to me in the first place. Onwards and upwards! ..... phil. |
Phil Manship |
Phil, thanks for reporting back and owning up to a small oversight rather than error I don't think anyone mentioned that possibility I normally say to carry a manual foot pump and a seperate reliable gauge (in my case instead of a spare wheel) and not to trust petrol forecourt and garage gauges for accuracy but I never thought of that in your case I once borrowed a friend's gauge and over inflated the tyres on a car I had making it skitish in the damp that morning to find that it wasn't as I assumed set on psi but bar |
Nigel Atkins |
Thanks Nigel, I must say I've learned a great deal from everybody who responded to this thread despite the eventual outcome, I guess thats what it's all about. Thanks again everybody! ..... Phil. |
Phil Manship |
Nigel, That sounds scary as 1 bar is 14.5 psi. I suppose instead of something like 20 psi you put in 2.0 bar and ended up with 29psi, that would make a difference. Pumping a tyre to 20bar doesn't bear thinking about. My compressor runs to 10bar or 150psi and I wouldn't want that in a tyre either unless I was well away from it and had the camera rolling to catch the result. |
David Billington |
and you've reminded me of always test the test equipment - but who checks the checker :) |
Nigel Atkins |
David with my eyes I probably didn't see the decimal dot ! yes sorry you're right I fogot about the dot I think I had those tyres at 22 and 24 psi - lot cars have those pressures it seems :) - but was pumping to 2.2 and 2.4 bar the car was new to me the day before but I knew it as it used to belong to my friend who we were travelling with and he was wondering why I was taking it so steady |
Nigel Atkins |
I keep getting timed out I think it was the first time I'd ever used a digital tyre pressure gauge and the chap that lent it to me had just checked his MGB tyres so like an ass I also assumed it was on psi and/or perhaps with my fat fingers I switched it over without knowing |
Nigel Atkins |
Nigel, We may never know but I've heard a few stories over the years such a new tyres on the car and a spin on a wet north circular, no one hurt. On investigation the tyres were at like 50psi from the tyre place, once corrected all was OK. No idea what caused that but what springs to mind is a mate that used to work at Land Rover told me they found that the guy that punched the engines numbers was dyslexic, I would have though that might have been automated but apparently not at the time. |
David Billington |
I once tightened the front hub nut on a metro to 250 lbft instead of 250 Nm. That was a bit tight, turns out I actually did it to about 330 Nm... |
Rob Armstrong |
David, it wasn't me at that tyre place 'onest I know some will overinflate new tyres to wear/bed/scrub(?) them in for the first however many miles I once got a new set of Bridgestone tyres and the fitter asked me to take the car off the lift, which was unusally as he knew me, he said they were so greasy he wanted me to do it and that I should give them a spin on the road outside as I left, so I did and the car slid a bit one way between the parked cars and the other way as I quickly lifted off, when he said they were geasy he wasnt joking yes Lawrence I have in the past been even more stupid than I am now |
Nigel Atkins |
This thread was discussed between 24/05/2012 and 28/05/2012
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