11 replies to this topic

[hecj]

Pushed my 998cc mini up to 65mph today, which embarrassingly is its fastest speed yet, however the steering started to become strange.

The car started to wobble on the road even though I kept the steering wheel completely straight, it also felt like when I compensated by steering the opposite way it did nothing.

I was wondering if this is a common problem with minis or if I need to check my steering out?

Cheers

[Alex_B]

Does it feel a bit light and wandery almost, if so thats what mine feels like above 65, and find my arms tire a bit due to damping the steering and keeping it straight, but im used to modern cars,

[RobWill116]

Can you describe it further? Sounds unusual to me, I have a 998 and its fine at 65

Edited by RobWill116, 22 May 2012 - 10:44 PM.

[Simont]

Even my 1999 Fiesta wobbles when i reach a fast speed,
another solution might be to check the wheel balance, this can cause wobble,

[hecj]

Yeah the steering feels very light, wandery would be a good word to describe it.

Would the wheel balance only cause it to wobble at higher speeds?

Another point to mention is that my mini pulls slightly to the left when on a straight road if I let go of the steering wheel

[TA2DMAC]

If it's pulling it could be in need of a brake adjustment. You could have one or more of them dragging. Check opposite of the direction of pull first. Also make sure the hand brake is fully released. It could be sticking. If the tires are not balanced there will be a point at which you will definately notice over slower speeds. Mine does the same but smooths out around 75 which is kind of odd.

[tiger99]

I am guessing that you have a rubber mounted front subframe, and some of the mounts have failed, most likely the rear mounts at the toeboard. The design is just plain wrong, and they never last very long. If that is the case, replace the whole lot with a solid mount kit (NEVER mix solid and rubber, or you will get serious structural cracking, and don't bother with the poly mounts which are available as they are utter trash).

But you should also check all suspension and steering components for wear, especially ball joints, track rod ends and rubber bushes.

A 998 should be utterly stable at 65 mph, in fact they have hardly got going at that speed, and can reach alomost 100 downhill, still stable, on normal wheels and tyres. They do respond instantly to steering input (not the rubber mounted ones!), but that usually troubles only people who have been driving sloppy old cars.

They usually pull slightly to the left due to road camber, if you can get it in the middle of a road you may find that it actually runs straight, but in any case broken subframe mounts or bent tie rods would cause it to pull.

[hecj]

Is it important to replace both the fittings for the front and rear subframes? If that is my problem

[tiger99]

No, the rear subframe is totally independent, and has its own set of 4 rubber mounts, which may occasionally become a little bit sloppy and need replacement. They are unlikely to be your problem, however they are cheap.

The front subframe has 6 mounts. Originally they were all solid, which worked well, but some time after Issigonis had retired, some idiot decided to try to reduce noise and vibration levels to please lady drivers, so the rubber mounts were introduced, which spoil the handling, even when they are in good condition. Both the subframe and the bodyshell were modified to fit the new mounts, which is why a conversion kit is needed to revert to solid.

At the same time as the front rubbers were introduced, two of the four rear mounts were changed to fit softer rubbers, but they only changed the brackets and bushes, not the subframe or body shell in that area, so it is trivial to swap rear end mounts, barring rusty bolts of course, if you ever need to.

[hecj]

Is changing the mounting for the subframe a big job? Or do I need to just get something like this http://www.minisport...o_SPDSP601.html

Edited by hecj, 26 May 2012 - 11:30 PM.

[tiger99]

That kit should do the job, and I think it is a fair bit cheaper than a set of rubber mounts. It is not a terribly big job, but you have to undo a few bits like top engine steady, possibly clutch slave cylinder (don't disconnect the hydraulics), track rod ends, fuel line, probably brake lines at the master cylinder (need to bleed afterwards), and be careful of the wiring. The car is raised and supported by load spreaders under the front floor (a length of 4*2 timber across the car, on two axle stands, is ok), the subframe is undone and lowered a few inches on a jack, to give room to take the old mounts out and fit the new.

If the brake lines are bundy or cunifer (not copper) you may get away with not disconnecting them if you are careful, but they may need reshaping afterwards and you should put a spanner on all the unions to nip them up in case they have loosened. Depending on your brake system, there may only be one line affected , from the PRV to the double banjo on the subframe, and if you unclip it, there may be enough length to allow the subframe to be lowered a few inches.

Only lower it far enough to get the top mounts at the bulkhead out, the front teardrops and rear toeboard mounts are easy.

If you have a decent tool kit, half a day, if you have never done it before. I think that might come down to 2 hours with practice.

[hecj]

Thanks very much mate, might have a crack at it but probably end up taking it to the garage!