Sheared off bolt that attaches the sump casing to the bellhousing

[7 wonders of the world]

1-Plus gas it for a few days to penetrate

2-Spend a good 30 mins with a toffee hammer and punch just tapiing the remaianing stud - the vibrations help break any corrosion

3-It may then tap out with the same punch anti clock - but this is a long shot

4-If you have access to a MIG you can weld a M6 or M8 bolt to the end of the remaining stud and if you have been patient with points 1 and 2 it should come out.

[aerobod - near CYYC]

If you can undo the pan and move it forward about 5 or 6mm, use a couple of pieces of steel sheet about 1mm thick and put a 90 degree bend in each, place them either side of the gap and hold them in place with a block of wood and a jack, away from where the bolt is. Then use a 2mm or thinner cutting disc carefully inserted between the two bent pieces of steel that will be used as a guide and to protect the aluminium casting faces. It should then be easy to carefully cut through the sheared bolt. With the pan removed, you can then take it to a specialist for removal with a screw extractor, if you are not able to do it.

The more space you can make by moving the pan forward, the more bolt shank you can leave to potentially just use mole grips or equivalent to remove the remains, as opposed to a screw extractor.

in terms of the bolt characteristics, it is likely either a 10.9 or 12.9 bolt, as hex cap screws have to be fairly hard to resist rounding the hex socket. This means that a conventional high speed steel tool such as a twist drill or hacksaw blade will not cut it, as they will not be hard enough. Abrasive, tungsten or other none HSS blades or tools will be needed. If the bolt is M10 x 55mm, any fastener supply shop should be able to supply replacement bolts, I would personally use a pair of 12.9 replacements, which shouldn't cost more than a pound or so.

[elie boone]

Drill a 5 mm or 6 mm hole in the bold and use a impact screw driver to take the piece of bolt out, use the + bit to do it

[LawrenceR]

1.Centre punch

2. Left handed colbalt drill bit

[glasgow]

Update:

The space under the car is limited and I may not be able to finish the job so decided to the car to a mechanic and I think it was the right desicion. Car is there since 8am and not sure when it will be finished.

A) believe it or not the other bolt (driver's side) is also sheared off and whoever done that has attached the head of the bolt to the rest of the bolt with silicone  so now I have 2 sheared off bolts

B) Sump was VERY difficult to move forward. They tried hummer and no luck. They ended up using welding torch to heat up the aluminium bellhousing in order expand the hole so the bolt can be freed. (Well, that what they done and I hope no damage happened)

C) with more hummer on the bolt itself, the sump finally started to move forward 2mm (I hope the tread inside the sump hole is still ok after all these strong  hummer knocks on the bolt)

D) now they managed to introduce an air hachsaw in the gap between the sump and the bellhousing.

E) air hacksaw is cutting in very slowly as the bolt is a hardened metal. Many blades are being used

D) Work stopped for lunch..... 

 

After I saw all that I decided to go for the sump gasket modification and gett rid of the foam (don't want to have this experience again). I did the holes like Ian B pic in reply No.2 in this threadhttp://www.lotus7.club/forum/techtalk/sump-gasket-mo

I made the 2 holes with drill number 6 which I think is slightly smaller than what is shown in the pic, is this ok?

 

[John Vine]

What a tale of woe!  It sounds like the previous owner was desperate to cover something up.  I'm amazed that anyone could shear those hefty bolts without first wrecking the thread in the sump.  I'm still left wondering whether they were snapped off following a coming together of the bellhousing and something like a cat's-eye.

If your mechanic could get the sump a little further forward, Aerobod's suggestion (post #27) would be a deal quicker than hacksaw blades.

Re the gasket mod, I'd go for something larger than M6 -- M10 would be good. You could always open out the M6 hole with a round file.

Hope you're soon back on the road!

JV

[nickh7]

Having just had those bolts out I cant understand how you would snap them . Oneside dosnt go all the way in so unless he was using an air impact driver and just over did it but like everybody else I'd have thought the sump would go first.

Hope it gets sorted

Nick h

 

[glasgow]

Sorted now. Tempted to put a new foam in. He says it there for a reason!

 

[John Vine]

Tempted to put a new foam in

Resist the temptation!  Is your mechanic aware of the problems that the foam can cause when it breaks up?  There's a lot in the archives about blocked oil pick-ups etc etc.

JV

[Ozzy]

Ditch the foam Ahmed!

Removed mine about 8 years ago. Last time the engine was stripped down, about 3 years ago, big end shells and crank in A1 condition, despite my usual heavy cornering! And I can see the pressure drop on the mechanical gauge, which is always a bit alarming!

 

 

[SM25T]

Lose the foam !

[Ozzy]

Does anyone have a picture of the gasket mod they can send to Ahmed? Might as well do it properly, whilst the sump is off.

Oz......

[Jonathan Kay]

Thanks for the update. You'll be fixed soon.

Jonathan

PS: According to mutltiple YouTube clips they'd be better off with a Land Rover than a Hummer...

 ;-)

[glasgow]

Well, the sump is now back on.

BUT, the new problem is the chap used a stuff called "mercedes engine seal RTV". He was very quick in applying it on both sides of the gasket and I didn't have time to think or "object". I was slightly concerned this stuff may breakdown and block the engine tubes. I googled and found exactly what I didn't want to see

https://mercedessource.com/problems/engine/using-silicone-rtv-gasket-adhesives

the car was driven today for about half an hour after the stuff was applied.

-Should I go back to him and ask him to remove this silicone (doesn't look nice after all the work he has done today)

-should I just leave it as it is and possibly nothing will happen

-should I remove it my self (but if any problem happened to the engine he will say why I didn't tell him)

 

[glasgow]

Couldn't sleep all night. Early morning to the garage. Stripped everything down and as expected lots of small silicone pieces all around the gasket edges. Some of them are loose and ready to go somewhere. Managed to clear as much as I can. Big coffee mug then off to work.... Eh, the fun of owning a caterham 

[7 wonders of the world]

If used correctly there is nothing wrong with RTV, it's used to seal most modern engines, The Ford / Mazda Duratec uses it extensively.

RTV is less likely to break off that normal silicone sealer, it should be appiled in a neat 2mm bead central in the mating face so once compressed it covers the full mating area without excessive amounts being displaced inward.

Don't blame the product, blame the guy squeezing the tube !

 

[John Vine]

Does anyone have a picture of the gasket mod they can send to Ahmed?

Here.

JV

[CharlesElliott]

There is no need to use RTV on the gasket, but if applied properly, no issue.