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Sierra Halfshaft Bolts
smdl - 14/4/06 at 12:09 AM

Currently struggling through getting these out. After breaking two torx bits (one with impact, one by hand), I gave up and got the grinder out. New process is to grind a flat and then use the air chisel to start it rotating. Then use vice grips to keep it moving.

Seems to be working now, although each one is a right b*****d.

One question -- is it important to keep the little two-bolt bridging plates in their original positions? Sorry for the poor description, but I'm referring to the little plates that go between each set of two bolts.

Thanks for any input.

Shaun


ReMan - 14/4/06 at 12:40 AM

No. there just posh washers

I think some just grind the heads off completely then unscrew the remais quite easily one its apart

[Edited on 14/4/06 by ReMan]


smdl - 14/4/06 at 12:55 AM

Thanks, ReMan. Nice to know that I don't have to worry about the "washers".

I was trying not to damage the actual flange by grinding too far down. Seems I've got it down to an art now, as the last one came out in less than a minute. That's 4 down, 20 to go...

Shaun


James - 14/4/06 at 12:56 AM

quote:
Originally posted by ReMan

I think some just grind the heads off completely then unscrew the remais quite easily one its apart




Yes, just grind the whole head off, the joint will then just fall apart!

Then replace with socket head caps.

Cheers,
James


smdl - 14/4/06 at 01:01 AM

Cheers, James.

I definitely will not be using these torx heads again!

Shaun


hector - 14/4/06 at 08:36 AM

just make sure you refit with 12.9 grade bolts as all your torque goes throu them little beauties and they need to be TIGHT!


NS Dev - 14/4/06 at 09:29 AM

Yep, to back that up, make sure that you torque them up to the Haynes figure (I actually use a tad more, calculated figure for the bolts involved, which comes out at 48Nm)


Peteff - 14/4/06 at 09:30 AM

The torque goes through the two surfaces that they hold together, not through the bolts. Don't try to overdo it when you tighten them as they break instead of stretching or twisting like lower grade bolts.


NS Dev - 14/4/06 at 09:46 AM

You're dead right Pete, but what I will say is that you'd be surprised how far those 12.9 grade capheads will stretch!!

I overtorqued a full set and only really realised (though I thought something felt wrong) when the bloody 24th one snapped!!! (none of the others did!)

I'd done them up to 68Nm iirc

The ones I took back out had all necked right down to about 7mm for a length of 5mm at the base of the threaded section, but as I say only 1 snapped!

They were Unbrako bolts, which are VERY good quality.


Cousin Cleotis - 14/4/06 at 12:18 PM

ive got a digital torque wrench, i built an entire engine with the thing set on lb-ft instead of Nm, big end caps tightened to 50lb-ft instead of 50nm, etc. i assume its still alright, the customer hasnt come back!

Paul


smdl - 14/4/06 at 02:22 PM

All great advice, and very much appreciated.

Shaun