MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - How Much Camber?

I just finished reassembling my front suspension using different A-arms and spring pans than I had before. All else is the same. After a test run I noticed a lot more negative camber than I remember having, and that the car handled more aggressively. It's been off the road for several months (long boring story) so my memory could be playing tricks on me.

I tried to measure the A-arms against the old ones but it's difficult when they are on the car to be exact. If they are different then it isn't by much.

So, my questions are:

How much negative camber should there be on an MGA? I put a straight edge on the floor against the tire sidewall, exactly vertical. I then measured 1 1/8 to 1 1/4" between the straight edge and the sidewall at the top of the tire. This is significantly more than the rear which has only a fraction of an inch.

Assuming I have the king pin trunnions the right way around, is there anything else that can contribute to this condition? Or maybe it's always been like that and I just don't remember it?
Steve Simmons

Steve -
That's 2.5 to 3 degrees neg camber, quite a bunch for a street car. Don't know the spec for an A, but TD is +/- 1 deg, and a B is +1, unladen. I imagine an A is very close to the B. If it is lowered, by intent or weak springs, then it will tend toward more negative. 1/4" on the A arms will give about 2 deg, so with good springs you would have about -1 final, pretty nice for a street car. That's about what aftermarket "negative camber" arms give you. Whatever you do, be sure to set the toe-in, since it will be drastically off with the new arms!

FRM
FR Millmore

Thanks for that. The arms are pretty close to teh same length but I just can't get a 100% accurate measurement without taking the 'new' ones off. These A-arms did come from a race car so it would make sense that they were negative camber.

New question: If I don't set the toe-in, what will the effects be? While test driving the car tonight it tracked very stable on the highway and handled like a dream in the corners, albeit a bit aggressive turning in. My wife is scheduled to take the car on a 175-mile trip in a couple days and I'm about to get on an airplane, so if she may have a problem then I'll need to have her take the car to a mechanic and make adjustments, or swap the arms back.
Steve Simmons

My book lists all versions of MGA as 1 degree positive to 0.5 degrees negative on full bump.

Steve
Steve Gyles

I noticed tyre wear on the outside edges and had the toe in checked. It was a long, long way out. After having it corrected I could not in all honesty notice any real change in handling, it seemed a bit better but that could have been my imagination, the difference was that small.

The bad tyre wear certainly stopped.

Malcolm
Malcolm Asquith

Steve, if you move the bottom of the tire out you will very slightly also move the steering arm connection outwards a bit and increase toe in. I'd doubt if it's enough to cause any real problem in tire wear in 175 miles but might be worth checking anyway.
Bill Young

It will be quite far off, and will have significant effect on tire wear (and fuel consumption). I destroyed a set of tires by replacing a ball joint and "putting off" checking toe for less than 1000 miles.
It should take maybe 10 minutes to set the toe-in, only have to adjust the steering side rods. Even doing it by eye sighting down the side can put it within reason. An alignment shop shouldn't take any longer. Much easier than changing the arms again, and you'd still need to set the toe anyway!
You may well find that the handling gets even better, without the "a bit aggressive turning in".

FRM
FR Millmore

Thanks everyone. She is off in the morning with the car as-is. The trip will only be about 135 miles, all easy highway driving.

I will be replacing the arms again anyway because I don't see any real reason to leave that much negative camber in the wheels, since this car is never going to be pushed hard enough to take advantage of it. We do take it through the canyon roads at a pretty good clip, but not as hard as some of the other cars. Plus, the wife doesn't think the negative camber looks good, and it's technically her car. :)

I will probably swap the negative arms with the standard ones on my '65 B since it's more performance-oriented. I still have the old original arms from the A, but I wanted arms with a sway bar attachment so the B arms would be a better bet.
Steve Simmons

I'm back home now and have had a chance to inspect the car after its trip. For the archives, there is no unusual wear at all after approximately 230 miles of highway and 70 miles of canyon driving. I have not measured exact toe-in yet but it's safe to say that however much toe-in is caused by negative camber A-arms is not enough to do short-term damage to the tires. I will of course correct the situation but I thought others might find this interesting.
Steve Simmons

But we don't know where it was to start! Might have come out just right.

FRM
FR Millmore

The alignment was by the book last time it was done. Unless something has bent, it should still be by the book. The alignment was performed by an MG repair shop. I did not oversee the work so I can't say they didn't make a mistake, but I can report that in several thousand miles since the alignment there has been no uneven tire wear.

I suppose I can measure it before and after I put it all back right. That would put the question to rest.
Steve Simmons

Steve,

I drove my TD about a 1000 miles with 1/4 toe in by mistake... no wear on the tire, but it sure handled nicer after I changed it to 0 toe.

You can change camber by changing the angle of the shock mount. Shims are available for the purpose. Or... take off the race arms as you are planning. Shimming can be down by simple loosening of the shcck mount bolts and driving in the shims. See my website under front suspension.

warmly,
dave
Dave Braun

This thread was discussed between 10/11/2009 and 14/11/2009

MG MGA index

This thread is from the archives. Join the live MG MGA BBS now