Technical Hub suspension bolts - strength class?

[atom0007]

Had a search here, can't find the answer.

Does anyone know the strength class for the nuts and bolts on the lower suspension strut, at swivel hub? Thread type and bolt length would be useful too.

Any specific torque setting on them, apart from ft?

What a dog to get them off....

 

[flisko]

front hub?

 

[atom0007]

Thanks, but I mean the bolts that attach the suspension strut to the hub (there are 2).

And I'm now going to buy a 27mm offset ring spanner for the top mount nut. That's a tool that I'll use twice in my life....

 

[flisko]

ohh those 2 bolts, nothing in autodata about that, just tighten by hand

 

[atom0007]

might go a bit tighter than that

 

[flisko]

windy on max torque

 

[judderbar]

Thanks, but I mean the bolts that attach the suspension strut to the hub (there are 2).

.

Haynes has 75nm for those bolts. They should be a high tensile bolt and are very expensive from Fiat

 

[Brendan W]

Any markings on the heads of the old ones ?
They are probably some variety of hi tensile i.e. 8.8 , 10.6 or 12.9 and may have had some heat treatment. I am wary of using anything other than oem for hi load parts out of ignorance more than anything else.

 

[digger58]

Everytime I hear about visiting main dealer for nuts and bolts I am reminded how luck we are here...http://www.hassetts.ie/

 

[atom0007]

There's plenty of places to buy them.....once you know what they are. As said above, the strength mark should be stamped on the nut and bolt head. But 15 years of action means they are long gone.

They are m10 X 70mm, 1.25mm pitch (i.e. Metric fine). The nut and bolt are both flanged, and the nut is a nyloc.

Would be great if someone knew the strength, as above they are likely to be high tensile. Too low and they're not good enough, too high and they might be brittle.

 

[judderbar]

There's plenty of places to buy them.....once you know what they are. As said above, the strength mark should be stamped on the nut and bolt head. But 15 years of action means they are long gone.

They are m10 X 70mm, 1.25mm pitch (i.e. Metric fine). The nut and bolt are both flanged, and the nut is a nyloc.

Would be great if someone knew the strength, as above they are likely to be high tensile. Too low and they're not good enough, too high and they might be brittle.

Mine are marked AL R10 as per the photo.

One of mine snapped off both ends and the bolt was marked H8.8 which I thought was not a high tensile grade and I replaced it very cheaply with one marked 8.8 from the local builders. All the other bolts were marked identically as on the photo.

Brendan says H8.8 is high tensile so I am a bit confused now. But definately the broken one was marked H8.8 and the others were all identically a different grade.

The nuts were fancy looking but were not nyloc.

All the bolts had the same course 1.5mm thread and were original for the car.

 

[atom0007]

Interesting, what were the other three marked as? How did the fourth snap?

8.8 is high tensile, as are the other grades listed above

 

[judderbar]

Interesting, what were the other three marked as? How did the fourth snap?

8.8 is high tensile, as are the other grades listed above

Here you are.....just cleaned one off and as good as new more or less.

The fourth one snapped at the nut and at the bolt head when i tried to get it off and i still had to hammer like hell to get it out - took the track end off to get a swing on it. The others still had the grey grease on them along the length of the bolt so were much easier.

 

[atom0007]

Grade 10 high tensile bolts, the rest of the marking are the maker's forging

 

[atom0007]

Interesting, what were the other three marked as?

And I should read the posts when I am less tired....

Painful to get the bolts off, almost as bad lining the hub and damper up again

 

[atom0007]

I would have expected 10.9 to be on them though, so the jury is still out

 

[judderbar]

as bad lining the hub and damper up again

I got that down to a fine art. Have a punch handy that will go partly into the hole when you get it more or less lined up. Put a crow bar in the lower wishbone hole from the top and press the other end of the bar down. Put the punch in and rest. The other bolt will fly in with just a bit of wiggling of the strut and the bar and then the rest is easy.

 

[atom0007]

Good tip, I'll try it.

I wonder if anyone ever tightens the top strut bolt (first one onto damper) with a torque wrench. Does anyone really have a 27mm crow foot adaptor like Haynes says to use?

 

[judderbar]

Good tip, I'll try it.

I wonder if anyone ever tightens the top strut bolt (first one onto damper) with a torque wrench. Does anyone really have a 27mm crow foot adaptor like Haynes says to use?

I just bodged mine on somehow by lying them on the floor and I think standing on the adjustables that were just about able to get hold of the nut. Good enough.

 

[atom0007]

Not too different to my effort