15 replies to this topic

[bikenutmart]

Just finished a complete rebuild of the front suspension ,brakes and steering, am I right in thinking that certain bolts shouldn't be tightened until the full weight of the car is on the wheels, at the moment its on axle stands under the front subframe, none of the bolts are tightened up yet .Is there an order to do this,as I don't want to put any stress on anything.Thanks Mart. 

[ChopperHarris]

Its recommended, but to be honest with the limited articulation of Mini suspension I don't bother had have not experienced any problems in 40yrs

[minidaves]

do it up, then when you have run it down the road and back check everything, then after a couple of weeks if all new bits

[bikenutmart]

Thanks Chopper!!

[kezzkitkat]

I tend to brush abit of ink on the bolts and nuts so I know I've done them tight the tower bolts maybe abit loose once the vehicle is on the floor but other than just tightened everything and keep threads clean for tracking and adjustment to bottom arm /tie rods from there adjustable

[59 Speed]

I was always under the understanding that the bottom arm nut (where the pin goes through the subframe) should be left loose until the car is on the floor.

Edited by Smackfiend, 27 December 2015 - 05:48 PM.

[Wim Fournier]

At avery point where there is a rubber bush inside, wait until the car is on its wheels and has run a few hundred meters before tightening. If not, you can be sure the rubber is under tension from the first time the car gets down on its wheels. So, the rubber is twisted from the beginning and wil deteriorate earlier.

Edited by Wim Fournier, 27 December 2015 - 06:31 PM.

[kezzkitkat]

I have to disagree I wouldn't leave anything untightned weather I'm going 100meters or 1000miles
As for the poly bushes yes there going to deteriorate no matter what you do.
the bottoms poly bushes are offset so providing you get them roughly in the right place and make sure the bottom pin is tight and correctly fitted to the subframe. Then should be ok . You can use a jack and lift the hub assembly up and down to settle the new bushes

[bikenutmart]

Thanks for all the replies Guys!! Mart.

[nicklouse]

to be honest the only nuts that really need to be tightened up when the wheels are on the ground are the nuts for the cranked pin going through the inner lower arm rubbers as it is them that have a rotational force on them.

[tiger99]

That is correct, and it is very important that it is done at normal ride height, whatever you have set that to be, because the rubber bushes can only operate through a limited angle. Worth re-doing if you substantially adjust the ride height. They operate in tosional shear, not by rotating on the pin, and the permissible angle is quite small because the bush is quite thin, to avoid undesired compliance in the lateral direction, which would cause camber and toe changes. If the angle is exceeded, the bush deteriorates or fails. No need to drive the car with anything loose, just set it on a flat surface, give it a few good hard bounces, and tighten the nuts.

 

It is useful to know that this applies, in general, to ALL cars with elastomeric suspension pivots, i.e. almost all modern cars except a few exotica. However some are to be set at a particular height which may not be the normal ride height, because the suspension is non-linear and the deflection above and below normal are not equal. The correct setting is invariably in the Haynes manual and often involves measuring a tyre to wheelarch clearance, or distance from a suspension part to the body.

 

In this particular case, poly bushes seem to be in use, and those can't flex in torsional shear. Nor can they flex to allow for a misaligned pivot axis, or anything else that requires much more than a simple rotation about the pin. I am totally sceptical about some of the claims made for them. However, if they are pivoting on the pin, hopefully with a stainless steel sleeve and washers, it would not be necessary to loosen the pivot, and re-tighten at normal ride height. That is also true for Rose joints and other free-running metallic bearings.

[mini93]

Rather than driving the car any distance.

 

Put the car on stands, with a jack under the corner, be it wheel or hub. Jack the car up till it just starts to lift off the axle stand and tighten the joints... You can even load the car up with a friend or 2 if you wanted to get the vehicle weights more representative of what you would usualy see on the road.

[Spider]

I just tighten everything while on the bench and then at about 500 - 1000 km run the spanners over it again.

 

However, if your Mini has the Rubber type Universal Joints, leave them loose until you get it on it's wheels and preferably at it's 'finished' ride hight, while it's at the ride hight, only then tighten them, you can do that from a Pit or Ramps. If you tighten them in any other position, they won't last too long at all.

[bikenutmart]

Perfect!! Many thanks everyone, mine has hardy spicers so no rubber couplings to worry about, also has minispares poly bushes with s/s sleeves so again, so I can tighten everything up in the garage. Mart.

[nicklouse]

Perfect!! Many thanks everyone, mine has hardy spicers so no rubber couplings to worry about, also has minispares poly bushes with s/s sleeves so again, so I can tighten everything up in the garage. Mart.

I would not.

Drop it on its wheels first then tighten the bottom nut. Or you will be damaging the poly bushes as they do get squished between the arm and the pin and the subframe.