Damaged Sump Bolts

[luk3333]

I've got a leaky sump gasket, but when I last did up the bolts I accidentally took the thread off the inside of 4 or 5 of the nuts, and now I can't get the nuts off to remove the sump. It was really strange, they were barely tight and they just went loose and then just kept going round and round, almost like the thread was made of aluminium. Has anyone had this issue before? Can I replace the nuts and studs with something stronger that won't strip so easily?

[jay_howie]

They shouldn't strip, someone may have done them up too tight and stretched the bolt or cross-threaded it. U should be able to replace the old studs with nuts and bolts instead. High tensile and stainless wont let u down!

 

http://www.probolt-australia.com/

[love ke70]

stainless will let you down. its terrible for bolts.

high tensile yes.

replace studs with new standard ones should be more than enough if the sump is straight and the gasket is good. if one of these things is not right, it doesnt matter what you do it wont leak. A sump nut only needs to be a twerk more than finger tight really.

[luk3333]

Ok thanks, have you got those studs out before?

[luk3333]

Also what makes stainless bad for bolts?

[B.L.Z.BUB]

Also what makes stainless bad for bolts?

 

Stainless is soft.

[love ke70]

not those ones specifically, but they didnt come in the block, so they will come out, so bolt off or rost off for a day, then vice grips and they will come out I should imagine. you can practice the 2 nuts technique if your that way inclined.

 

to further Reed's statement re stainless bolts.

 

Stainless is a very hard metal to work with and it hard on tooling, ie, to drill through it or cut a thread on it is hard, but to tighten a nut on a stainless bolt it is easy to strip the thread or snap it in half from the twisting force. just like when you try and run a stainless screw in, your much more likely to strip the head or snap it than you are with a steel screw.

 

Cheers

[altezzaclub]

The correct torque is only 4nm, so you would need to be using a torque wrench when working on your car to get a feeling for that.

 

When I started on the rally car with Steve I put bolts with a few nuts each in the vice and had him tighten them up to the normal torque for each size bolt. Then he checked them with a torque wrench and spent an hour learning how to tighten each diameter bolt up correctly with a ring spanner. This would be a good exercise for anyone who is working on cars. Sadly most of my cars have had precious owners who have been gorillas!

 

Try to get the nuts off with the studs in place if the stud thread is OK, maybe make a little bent fork that you can push the nut down with while you turn it. If not I'd lock two nuts against one another on the stud, just hold the lower one and turn the upper one down onto it then turn the whole stud out as the nuts lock up. If not, there are stud removing tools around.

 

Is the motor out or still in the car? Mine leaks because I'm not going to try to drop the sump and seal it until I take the motor out next, its a dog working under there.

[luk3333]

Interesting, I would have thought since stainless has a higher tensile strength it would have been stronger, but maybe it is more brittle too.

 

Unfortunately, the engine is back in the car but I can see I'm going to have to pull it out to do this, dropping the sub frame is harder I've found. I was using a 1/4" inch wrench probably 150mm long handle and I didn't do it very tight at all, but I know it was more than 4nm. I know firm hand tight is approximately the lowest measure on my torque wrench. Thanks for the ideas to get it out, I was a bit stumped.

[Hiro Protagonist]

Interesting, I would have thought since stainless has a higher tensile strength it would have been stronger, but maybe it is more brittle too.

 

Higher tensile strength than what? Standard 304/316 grade stainless steel is weaker than just about any mild carbon-steel let alone alloy steel, and A2 grade stainless fasteners are only around Grade 5.8 in a carbon-steel bolt, which isn't even a high-tensile grade (8.8, 10.9 or 12.9).

 

I deal with steel day in day out at work, and stainless is only ever used for corrosion-resistance, never for strength (the fact that normal austenitic stainless can't be hardened makes it next to useless as a structural steel)

[luk3333]

Really? wow I had it all wrong. I thought it was higher tensile than mild steel. Thanks for clearing that up

[jay_howie]

Who cares if stainless is weaker, its sump bolts.... stuff all torque, and they won't corrode. I am very aware of the properties of stainless and other metals properties, its my job. However for what he wants it for, it should work well, if you want to pay heaps and get titanium or some crap, you can, but its a waste.

[love ke70]

and mild steel will work better. thats the trouble with you people who think you know best. the bloke is having an issue with stripping nuts, likely due to over tightening, and you want to suggest something that will strip or snap easy. sensational.

[jay_howie]

Then use mild steel, it was just a SUGGESTION, but with the correct torque there should be no arguement anyway, just remember we are trying to help someone out, not fight like schoolgirls. Back on topic, most hardware places should be able to give you what you want, eg Bunnings. There may be better places with bigger ranges, but its always had what I was after.

 

thanks.

[love ke70]

I would suggest any local bolt supplier before you go to a general hardware for something like this.

 

your the one who said you didnt care mate, I'm just trying to help this bloke not get himself into a world of hurt with a snapped stud and having to pull the motor out a third time...