14 replies to this topic

[ryomini]

Hello again good mini people,

 

the last few weeks have been tough, failed wheel bearing, blown gasket and just now I found the  car was making funky noises.  Fortunately I had removed all matting from the front and with my left foot I felt the subframe mounting plate MOVING !

 

The chassis iis split in several places around the front driver's side subframe mount.  I am cleaning it up, and guess I shall weld all the cracks. 

 

Is there a standard course of action for strengthening this area.  I saw a poster who has done a very extensive rebuild, Petrol Pete I think he is called, put an extra plate on the outside of the chassis

 

I was thinking of welding an extra plate to the inside of the chassis.  All advice very welcome.  I think my mini is wanting more TLC these days ;)

 

I will post the pix when I get back in from work tonight.  Back on the bicycle again already !!!!

[Retroman]

I guess its a later Mini with the rubber subframe mounts

 

Make sure you check and preferably do both sides

 

It is advisable to plate the inside too

 

It's likely to crack again at the side of the welded cracks

 

By plating the inside it spreads the load

 

Drill a few holes in the plate and plug weld them too, so they have pick up points not just the edges

[greenwheels]

Have a good look at the rubber subframe mounts. If the front ones have sheared then this will have put a strain on the rear ones as the subframe 'wobbles' about the top mounts. If they are failing then I'd replace the lot.

[ryomini]

Yep welding a plate inside and adding some plug welds makes good sense, thanks.  It's a '93 Spi. Right now I only have access to a little gasLESS wire feed but it should help to reinforce the area.  I need to get out and find a plate of 3mm.

 

If you add a plate to the outside (say 3mm) I guess it has no negative effect on the subframe position as I have seen another poster do this.

 

 

[nicklouse]

looks like nothing. remember the square plates inside the car are not welded on their edges.

 

get all the sealant off and it will not be that bad and will just be overlaps that have separated a bit.

 

cant see light though it.

 

PS: plating it on the outside will lift the front of the subframe causing misalignment issues and will stress the engine mounts as you will need to rotate the engine forward a bit.

Edited by nicklouse, 07 November 2018 - 01:15 PM.

[GraemeC]

Plating the outside will have some effect on the subframe alignment, but it will be slight.

Ideally the plate needs to be bent so it is in two planes (toe board and floor) as this will provide much more strength. However, if this is done on the inside it will overlap the panel joint, making a sandwich, which will make any future floor panel work very difficult.

I’ve never understood why no-one makes the solid rear subframe mounts to replicate the original solid mount subframes, putting one bolt through the floor - that would pretty much solve this issue from happening.

Edited by GraemeC, 07 November 2018 - 04:27 PM.

[sonikk4]

Looking at that lot, i would remove the old plate inside and fabricate a new one but make it larger and slightly thicker. Cut out all of the old damage and weld in fresh metal. Then weld back the newly fabricated reinforcement plate. 

[DeadSquare]

Metal fatigue !

 

Let that be a lesson to you.

 

That's what happens if you have too much power.

 

It wouldn't have happened with an 850cc.

[ryomini]

Well there chaps,

thanks for all the guidance

 

I am actually quite amazed at how darn good these litttle gasless welders are !  At first I made a pig's, but it is very possible to lay down a very good solid bead, they are small and not so expensive, simple to use and work well outside in windy conditions too.  The downside is the spool cost 30 - 35 pounds a go which is not cheap. 

 

I'll post some more pix soon.  I welded up inside and outside and then took the car for a good drive.  NO more noise, no more funny steering etc.  I then have added two long bars  (3mm plate)  over the top hole and one over the bottom.  (If needs be the welds can be ground off if it got in the way of another repair.  I think it should sit tight now.)

 

nice bead at 5.36

[ryomini]

All sorted for now

 

 

 

[Retroman]

Its a long way from pretty but it will do the job.

 

I like the pedals, where were they from do you know ?

[ryomini]

Haha

yes, I just can't understand how some people get such clean results (expertise I guess).  On a bench with straight clean stteel, I think most people could pull (or push) a good bead, but on all fours, head tucked under the steering wheel, glasses falling off your nose, a scrreen in one hand and a welder that sometimes sticks on the wire feed and putty that catches fire and metal that isn't always nicely in contact !  (I bevelled the plates before tacking them in, anyhow it seems to be solid and safe and can hide under a bit of carpet)

 

as for the pedals, I'll have to check,  I think they are ally and maybe italian ?  It doesn't go any faster than with the original rubber though ;)

[Homersimpson]

Haha

yes, I just can't understand how some people get such clean results (expertise I guess).  On a bench with straight clean stteel, I think most people could pull (or push) a good bead, but on all fours, head tucked under the steering wheel, glasses falling off your nose, a scrreen in one hand and a welder that sometimes sticks on the wire feed and putty that catches fire and metal that isn't always nicely in contact !  (I bevelled the plates before tacking them in, anyhow it seems to be solid and safe and can hide under a bit of carpet)

 

as for the pedals, I'll have to check,  I think they are ally and maybe italian ?  It doesn't go any faster than with the original rubber though ;)

I'm afraid a lot of this is probably due to the lack of gas possibly coupled with it not being clean enough before starting.

 

To get good welds you need the steel to be as clean as when it was new and a good dose of sheilding gas.  I've never had any good results from gasless welders but when returning to my old faithful Clarke 150 with BOC argoshield its fabulous, just fitted a new torch for my latest project and its welding like new.

 

Having said all of the above i'm sure you welds will be fine but if you want pretty give a gas MIG a go, its much much better.

[ryomini]

Homer cheers

here in Japan you need a licence to own a gas bottle - I can't take the written test, so the flux core is good for me. I will try harder to get the work area cleaner and will continue to struggle to master this kind of welding.

 

It's all sealed up now with urethane caulk

[Ethel]

Flux core does a better job with rust and dirt in my experience. 

 

i'm a little surprised no one's come up with a bracket to mimic the  solid mount subframe. The problem didn't exist before they lopped the end off the frame to fit rubber.