68 replies to this topic

[dyshipfakta]

The bolts will snap most of the time is spent drilling them out

[Cooperman]

The bolts will snap most of the time is spent drilling them out

 

Yes, that is so true! But we all just love doing it, don't we?

[GT Jimmy]

My bolts came straight out. Couldn't believe my luck

[cal844]

My suggestion is to drill a hole in the box where the subframe nuts weld onto the panel (from the cabin it's the horizontal surface immediately in front of the arch in the rear bin) and spray the nuts with penetrant oil

[Pete - W.Sussex]

Soaked mine everyday for a week, giving them a gentle tweak backward and forward each time and out they came.

[Dusky]

If you use 4 axle stands with two pieces of timber it is easy. Jack the car as high as it will go at the back by jacking on the subframe side members. Put two axle stands each side under the rear of the floor with a piece of timber about 12" x 3" onto each pair of stands. The rear edge of the wood should be in line with the end of the floor.
Lower the car onto the wood, undo everything including the exhaust, hydraulics, handbrake, dampers, and anything else attaching the subframe to the car, then remove all the subframe trunnion bolts and lower it from the bodyshell.

Exactly how I replaced mine last year but used new stainless nuts and bolts and also replaced all bushes with polybushes.

Where did you find stainless with the correct tensile strength?

[brownspeed]

Soaked mine everyday for a week, giving them a gentle tweak backward and forward each time and out they came.

I did the same with mine and the front set either sheared or the captive nuts spun!

1-Be prepared to find more rot behind the subframe.

2- if refitting with stainless fasteners- the chances are you'll need to pull the subframe into position using bolts. DON'T use stainless bolts to do this (I did) as they're likely to gall (mine did) fit it with carbon steel bolts first THEN replace them with the stainless ones once its in place.

3- at least one of the brake lines WILL probably shear (mine did)

Edited by brownspeed, 05 June 2019 - 06:28 PM.

[minifreek1]

 

 

If you use 4 axle stands with two pieces of timber it is easy. Jack the car as high as it will go at the back by jacking on the subframe side members. Put two axle stands each side under the rear of the floor with a piece of timber about 12" x 3" onto each pair of stands. The rear edge of the wood should be in line with the end of the floor.
Lower the car onto the wood, undo everything including the exhaust, hydraulics, handbrake, dampers, and anything else attaching the subframe to the car, then remove all the subframe trunnion bolts and lower it from the bodyshell.

Exactly how I replaced mine last year but used new stainless nuts and bolts and also replaced all bushes with polybushes.

Where did you find stainless with the correct tensile strength?

 

Smiffy's bits...

[nicklouse]

 

 

 

If you use 4 axle stands with two pieces of timber it is easy. Jack the car as high as it will go at the back by jacking on the subframe side members. Put two axle stands each side under the rear of the floor with a piece of timber about 12" x 3" onto each pair of stands. The rear edge of the wood should be in line with the end of the floor.
Lower the car onto the wood, undo everything including the exhaust, hydraulics, handbrake, dampers, and anything else attaching the subframe to the car, then remove all the subframe trunnion bolts and lower it from the bodyshell.

Exactly how I replaced mine last year but used new stainless nuts and bolts and also replaced all bushes with polybushes.

Where did you find stainless with the correct tensile strength?

 

Smiffy's bits...

 

enjoy the corrosion they will cause to the captive nuts.  and are they really the correct grade?

[Ethel]

I'd have to wonder about the same as Nick. The captives are likely less than perfect anyway and I'd far sooner try and drill out a broken high tensile bolt than a stainless one.

 

I hope were not putting the OP off having a go. It's just if you have to resort to tactics like Cal844 suggests you'll need welding capability and if you haven't your own, it'll likely be cheaper and easier to find if your Mini's still mobile.

[unburntfuelinthemorning]

I've never tried stainless fasteners.  Would I be right in guessing they are unmarked regarding what grade they are?

 

I've gone for conventional fasteners with a liberal application of copper grease as well as copious amounts of cavity protection to try to keep them turning.

[DeadSquare]

Because I hot dip zinc plate my rear subframes, it is a long time since I removed one,  but if, as suggested for ease of handling, the radius arms are removed, can't the big bolt that goes through the rubber bush in the mounting block be undone and extracted ?

 

This would mean that the 5/16" bolts into the captive nuts in the body do not have to be disturbed.

[Ethel]

Trunnions.

[unburntfuelinthemorning]

Trunnions.

No need for that language.

[Ethel]

 

 

I've never tried stainless fasteners.  Would I be right in guessing they are unmarked regarding what grade they are?

 

I've gone for conventional fasteners with a liberal application of copper grease as well as copious amounts of cavity protection to try to keep them turning.

Stainless should be marked A4-80* or some such. The number after the dash is the strength 80 being a near equivalent to the grade 5 it'd replace.

 

* this side of the pond anyway.

 

I find the originals are a bit longer than they need to be. I suppose you could replace them one at a time, once the frame's in place, with something more accurately sized. I've had a fair few that start to unscrew before they bind & snap.