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MG MGB Technical - Straight on steering wheel?
I've put up with my steering wheel being slightly off center since I got my 73B roadster a few years ago. I figured it would take a front wheel alignment to correct this. It is not a case of just rotating the wheel one spline when putting it back on the steering shaft. It's off about 1 degree clockwise when on one spline, and about 3 degrees counterclockwise when rotating to the next spline. So, correct positioning is somewhere between those two spline alignments. So, is the fix a front end alignment, or is there something else I can do so the steering wheel is properly straight when the front wheels are straight ahead? Thanks, BH |
BH Davis |
BH, It's corrected with tie rod adjustment as you mentioned if the steerig wheel splines will not bring it close enough. It will not take much adjustment to correct the centering, perhaps 1/8 to 1/4 turn of the tie rods. In this situation each tie rod is turned the same direction. Clifton |
Clifton Gordon |
Can't you just take off the wheel and re-align it? |
don g |
As Clifton says, adjust the tie rods. You may do this yourself without losing the alignment so long as you do exactly the same to one side as the other. Just make sure that you drive the car in a straight line prior to stopping and adjusting. If you want to really do a good job, there is also the string alignment method in the archives that is very easy to do and superior to the job the average bloke (there are a few rare exceptions) at the tyre place will do. |
Peter |
I've seen reference to this string method recently but I really don't like the sound of it. Surely it needs to rear wheels to be correctly aligned and more importantly directly (or with an equal offset) behind the fronts, which with leaf springs many tens of thousands of miles old probably isn't going to happen. I prefer the method given in my Celica manual of a bar and pointers, measuring the distance between a given point on each front tyre when that point is directly behind the axle, then rolling the car forwards one half turn and comparing it with the distance when those points are directly in front of the axle. |
Paul Hunt 2 |
what you must not forget is why is this steering wheel not in the straight ahead position, it would have been at one time so what has happened to it the first thing to do is have a 4 wheel alingment done,which will include a pre alingment check this will check to see if there is any play anywhere trim hights tyre pressures etc, then after the 4 wheel alingment you can decide what is your next coarse of action by looking at the readings you get,let us asume that the pre alingment check was ok and there were no faults found, and all the primary angles (castor.camber kpi) were all in spec,(perhaps even the track is wihtin spec) what you need to do is set the steering wheel in the straight ahead position and lock it with a steering wheel clamp, this is very important,now take a look at the readings for the track again,this time they will read diferent to befor, when you adjust the track dont forget that both track rods MUST finish up the same lenth all this adjustment must be done live on the 4 wheel alingment machine, then when you have done this your steering wheel will be in the right position, a good tip before you take it in to have this job done clean up the track rods and lubricate them so when it comes to adjusting them you can turn them with your hand this will ensure that they do get adjusted correctly and not just left differrent lenths |
andy tilney |
The original question reads (It's off about 1 degree clockwise when on one spline, and about 3 degrees counterclockwise when rotating to the next spline. So, correct positioning is somewhere between those two spline alignments.) Assuming BH's steering rack is centered and the steering wheel is clamped straight ahead with equal length tie rods and correct toe-in, the wheels will be pointed very slightly off the straight ahead position. To correct the error you have to lengthen one tie rod and shorten the other to get the wheels straight ahead. Lots of musts in Andy's post. I realize the 4 wheel alignment machine can provide lots of information and they are useful diagnostic information tools. But they don't tell you how to solve the problem. You can either rebuild the car until you find the error, if there really is an error or you can adjust the tie rods to slightly different lengths and be happy with the car. We aren't talking about a big error, it's not enough to make a big difference. 4 wheel alignment machines weren't around when MGB's were new so I suspect slightly off center steering wheels were centered with slight adjustments of the tie rod lengths. Clifton |
Clifton Gordon |
cliffton you say they dont tell youhow to solve the problem but they do and its just as easy to fix correctly as to fix it incorectly |
andy tilney |
In a perfect world the rack will be perfectly centred, the track rods of identical length (out of the track-rod-ends), the wheel perfectly centred, and the car moving in a perfectly straight line. But this isn't a perfect world which is why the Workshop Manual quotes tolerances for camber, castor, toe and everything else, and the track rod to track-rod end adjustment is used to compensate for minor practical differences. If you go to a 4-wheel alignment centre they will *always* find something off, and they *won't* measure the length of the track rods. They will clamp the wheel in the straight-ahead position and adjust both track-rod-ends to get the required toe with equal alignment to the rear wheels. The only alternative is as Clifton says - to rebuild the car again and again until you get the right combination of components to give you the perfect situation. I.e. it's a non-starter. |
Paul Hunt 2 |
paul the track on my car is spot on the track rods are exactly the same lenth the steering wheel is dead center and i did not have to rebuild anything, this is possible to do you just need to get it done by someone who knows how to do it? andy |
andy tilney |
This thread was discussed between 18/11/2007 and 23/11/2007
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