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MG MGA - MGA front suspension improvement, ideas???
I am restoring a MGA Coupˇ and want to know what is possible to improve front suspension. I read some changes king pin for MGB type as MGA's ones are weak. Is it true? This car will a smmer daily driver and I want it reliable, handling well and confortable.
Thanks for your input...
|Jean Guy Catford|
|J-G, if you decide to go the MGB route, I have a set of kingpins and hubs. Personally I think the MGA parts are quite adequate, but your choice.|
|While I haven't yet done this to the "A", the best single improvement to both of my "B's" was changing all the suspension bushings to "poly", instead of the rubber...That, plus a front heavier anti-sway bay, along with new poly bushings and rebuild on the rear springs, made a huge difference in handling...|
Of course , make sure all of your shocks are in first-class condition.
Time consuming, but not real expensive.
|Edward Wesson 60MGA|
|Dont worry too much about the MGA kingpins, they are pretty strong. I have driven my car pretty hard over the last 6 years and there is no noticeable wear in the kingpins.|
It may that MGB kingpins are stronger but probably they are less expensive and that is probably the main reason anyone would fit them, unless you intend to race or rally your car.
Just make sure you grease them regularly, I do mine 2 or 3 times a year which works out at approx every 800 miles.
I fitted a 3/4 " anti roll bar which has made an incredible improvement in the front end grip, the car corners like its on rails and feels great.
When I got my car it had negative camber front wishbone arms, a 5/8" anti roll bar, uprated front shock absorbers, harder suspension bushes and was lowered by about 1".
I loved the lowered look but the lowered suspension combined with the negative camber front arms caused the handling to be just horrible. The car turned in amazingly at lower road speeds but if you hit a bump or moved the steering wheel in the middle of a fast corner, the car would instantly jump to one side and become almost uncontrollable. I almost lost it on many occasions.
I have now swopped the negative camber arms for standard ones,fitted the bigger 3/4" anti roll bar, but retained the lowered springs and the car has been transformed.
It is superb to drive now and I find any excuse to get it onto the road.
The problem was that you should not combine lowering the suspension with negative camber wishbone arms, this causes excessive bump-steer which ruins the cars handling.
Negative camber on its own with standard height springs works fine and just gives you instant steering response (turn-in)
Lowering the suspension is intended to lower the cars centre of gravity, reduce roll and improve cornering. It maybe does do this but you will end up with reduced ground clearance and a much harder ride.
It works really well on the smooth road surfaces that you find on a motor racing circuit but on real-world roads the bumps can make your vision blur! :-)
I was following my friend Stuart in his MGA up some very bumpy Alpine roads last year, his car has virtually the same engine power as mine but has standard height suspension. His car coped with the bumps really well but I had to back off and slow down to prevent suspension damage, the vibration was so bad!
If you wonder why I havent changed the car back to standard height springs, its because I like the look of the lowered car ( I know this isnt logical but neither is owning an MGA!)
I will probably change the springs sometime but not just yet.
Hope that helps
attached pic of my (lowered) car behind Stuarts and Brookes cars
|X2 what Edward said. Be sure the shock absorbers work. Rebuild the suspension as new, but avoid the current supply of soft rubber bushings. Front A-arm inner ends, use MGB GT V8 type or poly bushings. Leaf spring rear shackles use poly bushings. Install a 3/4-inch diameter front sway bar (avoiding soft rubber bushings).|
Aside from the live axle in back (which we can't do much about), MG suspension is actually quite good as original (when it is in good condition). The front swivel pins are not too weak, but could be bent if you broadside a curb at speed hard enough to damage a wheel. Swivel pins may also suffer from micro cracks which may ultimately grow to cause a stress fracture. So at least once during your term of ownership of the car it is a good idea to have all of the front suspension parts crack checked.
My MGA has 400,000 miles and still has the original swivel pins. I beat the crap out of it autocrossing on sticky race tires nearly every weekend for ten years. I broke lots of original type steel wheels, but never had any problem with the swivel pins. Incidence of breaking of the MGA swivel pins is statistically rare (but you will hear about it occasionally). I have never head of one breaking after passing crack check testing.
I am a firm believer that converting an MGA to MGB front suspension is a waste of time and money. But if you have unfettered money to spend on a competition car, then it won't cause any harm to do it.
|Thank you very much,|
Fellow MG owners, I will proceeed as you said with original set-up and probably V8 inner bushing. I tried V8+poly on a MGB and all poly on a GT and I have preference for combined bushings.
But you pinpointed weakness on rear suspension and despite I have 3 complete independant rear suspensions ( XKE, SCORPIO, BMW 535) to possibly swap in MGA, it is not a staightforward operation...
|Jean Guy Catford|
|You can purchase an IRS that bolts straight in from Hoyle Engineering.|
Personally I would spend that money on a used Mazda! And keep the MGA as it is!
|I have never heard of MGA suspension collapsing. But it used to be common on the not dissimilar Morris Minor set up when the bottom swivel pin thread would wear and pull the bottom trunion off the the bottom of the pin and the wheel came out at 45 degrees. It happened to my dad and it was quite common to see Minors at the side of the road like this. |
I suppose this reinforces what Colyn, and myself do, i.e. keep the front suspension well greased and make sure grease is coming out of all 3 points on each trunion.
|P M Dean|
|MGA suspension collapse happened to my dad once, but it was caused by the studs for one of the front shocks pulling out of the frame.|
|I have experienced the lower trunion parting company with the kingpin in an MGA, so it can happen.|
Seem to recall that I was accelerating out of a roundabout on the outskirts of Cambridge back in 1978. The car was in everyday use at the time covering about 15,000 miles a year.
|Here is a pic that shows a broken Kingpin !|
It may happen and it does !
|One of my king pins was bent along with one of the lower wishbone arms. No idea how long it was that way. IIRC, it was on the opposite side from the shock that left the frame. I luckily had an extra knuckle/kingpin assembly from a parts car that I am using.|
How could I contact you? May be rebuilding B king pin is not a bad idea after all...
|Jean Guy Catford|
|Giovanni, the picture shows a dry king pin at the break. Did it have any grease? Could the lack of grease have contributed to the failure or was it just stress? Did it have a serious knock/accident?|
I would have thought them quite robust under "normal" driving conditions.
|King pins breaking is usually due to either owner abuse (lack of grease, which is just as likely to cause the trunion to kack on you) or bad parts. There were some after market king pins available for awhile with a sharp radius at the end of the top threads - bad machining that resulted in reports of several breakages.|
I've raced on those king pins for 4 decades. They are plenty strong for anything you'd be doing with them. I agree with Barney that swapping out to MGB is a waste of time unless you can't source parts. I used MGB on the Jamaican only because I didn't have and disc brake MGA spares hanging around.
I recommend the V8 Metelastic inner A arm bushes over any of the plastic alternatives. The plastic wears, the V8 ones do not, although they can conceivably perish after a few decades. When the plastic wears there is slop, road dirt can get in and cause wear on the metal pivots - very bad idea.
|The best thing that you can do is to get your tires (on the wheels) professionally balanced. Even the slightest out of balance wheel will cause vibration, and you will feel it at speed in the steering wheel. Properly balanced tires and wheels make the MGA perform well. I have a coupe and drive it hard. I switched to 60 spoke wire wheels from the original 48 spoke wheels- much better in cornering (stiffer). Once I got the front end aligned and the setup balanced, it handles very well. And yes, as Barney mentioned, make sure that your shocks are filled and working.|
I have two sets of wheels. For hard driving, I run Dunlop SPs on MWS 60 spoke wires at 34 lbs. A bit stiffer, gives a solid ride.
Not much else is needed. I did lengthen the battery tray to accommodate a larger 12 volt battery, and to balance the weight against the driver a bit better.
The picture shows the car with the 48-spoke wheels and whitewalls- only for show. For spirited driving I use the setup described above. Even with the show set, proper balancing is important.
This thread was discussed between 22/12/2013 and 26/01/2014
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