MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Chassis rail bolts question.

Hi Guys,
1972 Midget Mk III
Dopey question but I'll ask it anyway!
The o/s front bolt that holds on the front bumper iron has broken and looks to be corroded to hell & back.
The two on the nearest are a bit corroded but that's what Plus Gas is for.
I want to fit towing eyes( don't ask) so can I " just" drill out the old corroded bolt and fit the towing eyes with new bolts?
I plan to replace all the bolts with nice shiny new stuff.
Is there a thread or a bush within the chassis rail or is it just a plain & simple hole?
Can I remove these bolts OK or is there anything else attached that I need to be aware of?
Thanks all.
Cheers colin
colin frowen

Colin,
I had to fit towing eyes last year (for a don't ask reason too, and didn't need to use them anyway).

The setscrews that hold the bumper mounting brackets and towing eyes are into female, threaded, captive fixings within the chassis legs, so careful with drilling/extraction.

When fitting towing eyes you need to support the weight of the bumper and irons or remove them to get the setscrews in cleanly and keep bumper level across the front of the car. (To remove the bumper complete with attached support bar complete is only a matter of removing the two nuts that hold to the mounting brackets.)

I can't remember now if when I tried using slightly longer screws to allow for towing eyes thickness if I had to got back to original length as the longer ones wouldn't fully tighten.

I've never had PlusGas fail but I use plenty of time and patience and let the chemicals do all the hard work, spray, leave at least overnight or longer if possible, try to tighten fixing a nip before trying to loosen, if this didn't work I repeat the whole process again, leaving at least overnight again, until it does work.

I hope this makes sense, it's a very easy job or I wouldn't have been able to do it.
Nigel Atkins

Plenty of good quality penetrating oil, not WD40, and I would use a left handed drill rather than any sort of extractor. I'm not taking the piss about left handed drills they're fairly readily available and good for this job as they can often catch and wind the broken part of the screw out while drilling. A local engineering firm thought a neighbour they knew was taking the piss but it turns out a supplier about 10 miles away had a selection in stock so the engineering firm learned something new that day.
David Billington

After you get the broken part out, I'd run a tap through it to clean up any left over corrosion. You might want to do it to the other ones too, just to be safe.
Martin

3/8" UNF from memory at least on the frogeye.
David Billington

Now David has put it, yes I remember it being 3/8" unf, 1" long as standard.

Good advice on left handed drill, though I've yet to use one, and cleaning the thread. As I don't have taps I often use sacrificial screws but always check their thread with several screws on several different nuts and not just one as I've had new nuts, bolts and setscrews with iffy threads even from (previously) very reliable suppliers (more of the piss-poor parts syndrome).

If you want to take things apart again in the future you might want to also use some sort of anti-seize like copper grease, in which case don't overtighten and strip the thread.
Nigel Atkins

On a spridget having 1/4" UNF, 5/16" UNF, and 3/8" UNF covers most threads you're likely to come across that need cleaning.
David Billington

If having drilled out the damaged bolt, there isn't enough thread left in the female insert, then you could use a helicoil repair. They are very easy to use.
GuyW

in that area I wouldn't waste time with WD40 or Plusgas or oil, I'd use a propane or MAPP gas blowlamp with a fine point flame. There's no rubber or whatever close by to be damaged and 2 to 3 minutes of heat usually means they come out really easily.
David Smith

Mine got ruined. I've fitted through bolts with nuts on the end. They also hold the ARB strengthening angles on, and my towing eye (which is needed for sprinting - no mysteries here!)
Rob Armstrong

This thread was discussed between 25/11/2019 and 26/11/2019

MG Midget and Sprite Technical index

This thread is from the archives. Join the live MG Midget and Sprite Technical BBS now