Steering wobble

[Mrbenn]

My 77 B has developed a wobble when you get to just below 70. Like the one of the wheels needs balancing. But they're fine. It only happens in a straight line too. When I turn slightly it goes away. Any ideas?

[Ian F]

Check your tyres don't have a bulge in the sidewall. If it's on the inside it will be hard to spot

Ian F

[Not_Anumber]

Hard to spot plus it wouldnt be picked up by many wheel balancing machines where there is no weight on the tyre to cause the bulge

[Mrbenn]

I didn't think of a tyre bulge. I'll have to check them. They're both only a few months old. I was wondering if it could be kingpin or something with the steering rack.

[Ian F]

If you are absolutely certain that your wheels are balanced then testing all the joints with a pry bar with wheels removed might reveal some wear.
If all four wheels have been balanced then try swapping the fronts and the backs. This would clearly indicate if the problem lies with the wheels themselves

Ian F

[Bumpa]

Does a '77 B have Rostyle wheels? These can be hard to balance perfectly because the hole in the middle, where wheel balancing machines locate, is not always dead centre. My long experience with MGBs tells me that the design of the front suspension and steering is particularly sensitive to wheel balance and that vibration can be noticed typically around 60 - 70 mph.

My dad had an 1951 A40 Somerset with basically the same suspension set up. It suffered horrible steering wheel shake above 45 mph. Thankfully, it was so low powered that you rarely got up to those speeds on the roads of the early 1960s.

[Mrbenn]

Thanks for the advice. When I finally get a day at the weekend dry enough to sort it out then I will have a look. I know the place that changed the tyres balanced them on the centre hole. So I might call a few local garages to see if they can balance on the studs. They are Rostyles.