Actually with more of a description I'd also consider the diff....dragging in some way on one side. Just sounds like the description of LSD gone wrong.

Has the diff been checked? If there is wear in the gears it may translate into drive varying from side to side.

Posted same time as above^^^^^^^^

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Dave K.
1979 Moke Californian + 1981 'Coke' Moke

It has come to my attention that it may be the diff
Have you checked the diff?

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You're so square
Baby I don't care

Bit of a long shot, but you are running low on straws to grasp

It almost sounds like a front to rear weight transfer problem??? You don't have a miss-matched hydro bag on one corner, or a slight restriction in the balance pipe/hoses on one side of the car???????

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Is it crabbing at all? If so it could explain also... all the geometry in suspension looks right but if its crabbing it'll do that.

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Click here for the Turbo Conversion Thread!

It's been laser-aligned a couple of times, and set up correctly at the rear each time. If this was something that only happened with front-to-rear weight transfer in a corner I'd be looking at the rear, but the problem is evident in a straight line, and the steer happens so close to the transition between on- and off-throttle that weight transfer front to rear doesn't happen before the change of direction.



There's no LSD in this car, and the engine/gearbox/diff were rebuilt a few years after I got the car. This problem predates that rebuild, and survives it.. so I would think it's unlikely to be the diff in this case. Either way, I ain't pulling it out to find out



That's quite possible, I suppose. I've never had the bags (or the subframe for that matter) out of the car so I don't know what they are, but I'm dubious about the weight transfer theory only because I can feel the change of direction with a very fine throttle balance. As soon as the "slack" between on- and off-power is taken up (felt by the engine weight shifting forwards or backwards), the direction changes. At this point there's not enough engine power or braking being applied for the chassis balance to change.



No crabbing at all. Rear geometry is spot on.

Thanks for the suggestions guys, keep them clutchin' straws coming

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Simon

The adventures of an owner builder in the Tallarook Ranges

You say that most of the suspension has been replaced/rebuilt over time - how about CV's and uni's - are they still original to this problem?

Do you have shock absorbers on your hydro??? If you do, maybe borrow another set of shocks to rule them out. If you don't, maybe a set would reduce this problem???

Right at the start you said that it doesn't do it when it's riding on the bumpstops. To me this indicates it's most likely something loose in the suspension or it's to do with vertical suspension movement. You say that the suspension has been checked/repaired/rebuilt several times over time which leaves vertical movement of the suspension - my 2c is still on a possible miss-matched hydro bag.

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Ok since we are clutching at straws here is my list of straws for you.
1. Put a few bags of potatoes (or cement or anything) on the passenger seat. Does it still do it if you balance your weight? (Not implying you are heavy lol)
2. What are the tyre pressures like? Tyre squatting?
3. What shocks are on it? Could one be worn and ruining travel?
4. Have you tested with the quarter windows both open or one open? Aerodynamics?

Yes, most of this (not all) is tongue in cheek...

Pete

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Click here for the Turbo Conversion Thread!

It's got pot joints which are the originals, and the outers have been replaced a couple of times (firstly with the disc brake conversion, then again twice because they were duds).



Yep, shocks up front and competition bump stops at the rear. Shocks have never been replaced, but I have a new pair on the van which I can swap over, good suggestion.



1. Very good idea, I'll try that.
2. Tyre pressures I keep at 32psi all around, tyres are reasonably new A008's but again, the problem predates these.
3. See above, another good suggestion which I'll try.
4. Nice straw! I'll try anything at this point

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Simon

The adventures of an owner builder in the Tallarook Ranges

it sounds like you do have a small amount of play somewhere & you just havn`t found it (yet)

however,,, most minis have "This" problem anyways, & the older they are & the more abuse they have seen over the years, then the more "This" problem shows it`s ugly head

now, "this" problem is simply-->

Jack your car up on the passengers side, so that front wheel is in the air, turn the steering wheel full lock to the right, & then Have someone "wobble" the left front wheel quite firmly to & for, you sit inside the car & watch the front floor where the left/hand/side steering rack mounting is,,, you will most surely notice the floor flex in & out

this will creat some form of "bump-steer"

every mini has it to differing degrees,,, it became quite bad in our old speedway minis & rally minis where we then made stiffening ribs/braces to weld up around that area to help stop it

at one hillclimb i was even declined entry upon scrutineering because they deemed it unsafe as they figured the steering rack itself was at fault,,, untill i showed then the floor flex

it`s quite common but fairly un-noticed by the masses

it may be as simple as that, but it may be just that you have some play in the system still but have yet to find it

even a pair of "miss-matched" tie-bar rubbers will do it,,, like one is stiffer than the other, is all it takes

a tiny bit of "spongey-ness" in the left hand end rack bush is all it takes

a miss-match of lower inner control arm bushes will also do it,,, again one slightly stiffer than the other

have a far far better look & you will (should) find the problem

it`s not un-common at all,,, but i don`t stand for it,,, i won`t stand for it,,, i will not,,, & never will,,, i find it much better to sit down

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

One other thing I though of today while driving about, check the steering arms are the same type Left and Right sides, ie MKI and MKII and that they are not bent.

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if steering arms are not "a pair" , then cornering will be really weired, as-in, one way will be pretty cool (sort-of) & the other will bite funny & weired,,, minis with miss-matching steering arms are always weired & i`m sure (if this was the problem) then the original question would have been worded different, (just my thoughts tho)

ya just can`t miss it really,, well unless you have absolutely no feel at all

good thought tho & good time to throw it into the mix... makes him look harder for the problem

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Floor flex, the first I have heard of it but when you think about it every Mini I have ever seen under the front floor mats/carpet has been pushed up from grounding the car.
Unless you have grandmas car that wasn't rallied or have one with two new front floors this may be a clue.
Otherwise than your steering arms being loose, not equal in length or the tie rods not being straight or equal length then yours is a mystery.
Measure your tie rods as normally they were added in cars to be used in extreme conditions. Mini tie rods are fixed from the front of the subframe.
Some larger BMC cars had both front and rear fixed tie rods to support their front end geometry under severe bump conditions.
These can wear at the part where the tie rod affixes to the frame or subframe in the case of a Mini.
Check that the subframe mount has not worn the tie rod diameter down which causes a movement when you power on and off on the accelerator.

Not always that obvious Matt, maybe to someone like yourself, but not everyone

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I,m sure I,ve got my head around it , the floor is storing kinetic energy , over time with metal fatigue it gets more flex , if you are the last owner and you feel that the car is a bit loose or vague then components get changed , engine / gearbox stabilizers , suspension , tie rods , steering arms etc now of course you have put some inflexibility in the front/ rear end , the visual picture now is a rectangle piece of thin spring steel 15cm X 8cm with 5 centimetres in a vice and rest above and you grab the end ( as in the front end of the car ) with wide pliers, if you say that twisting left or right is the same as steering left or right with wheel travel you see what I mean about kinetic energy , at certain angles of the steering at certain speeds depending on the road surface ( camber / off camber ) that kinetic energy is released , now if you think about hard cornering and the inside wheel lifting I,m sure that the kinetic energy is being released backwards ( I,m not saying that causes the wheel to lift just the direction of release ), and a steep dip with a hard left / right where you don,t brake and put the power down a little early and the brief understeer/ oversteer kick back through the steering the kinetic energy is released forwards

At least thats what this delicious Port is telling me to think


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