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what tensile bolt for gearbox to prop
hootsno1 - 1/2/14 at 06:14 PM

Evening all
Could someone please let me know if 8.8 tensile bolt are up to the job to connect the output shaft from my mt75 gearbox to the pop shaft
many thanks
Mark

craig1410 - 1/2/14 at 06:20 PM

The ones I got from Burton Power were 10.9 and were supposed to be the correct part for Sierra diff to propshaft. I don't think I'd be happy with 8.8 for such a critical component. I realise this is different to your situation but might be of interest.

Cheers,
Craig.

hootsno1 - 1/2/14 at 06:41 PM

Thanks Craig
I have just ordered some 10.9 bolts I to thought that 8.8 were not up to the job just needed some else to say 8.8 are no good

Cheers,
mark

jacko - 1/2/14 at 06:42 PM

If you mean the 3 big bolts i am sure the ones i had where 10.9 or 12. 2 or there about's

hootsno1 - 1/2/14 at 06:55 PM

yes thats the one's I'm looking for

britishtrident - 1/2/14 at 07:38 PM

Just to put things straight most car manufacturers used 8.8. for this back in the day Ford were the only manufacturer as far as I know who used 10.9


The joint between the flanges transfers torque by friction not the shear strength of the boots the important thing is to remember and check the bolts for tightness after the first run and again after 500 to 1000 miles.

hootsno1 - 1/2/14 at 09:44 PM

Checking these sort of bolts are on my list of things to go though after the first 500 miles already

craig1410 - 1/2/14 at 10:30 PM

quote:
Originally posted by britishtrident
Just to put things straight most car manufacturers used 8.8. for this back in the day Ford were the only manufacturer as far as I know who used 10.9


The joint between the flanges transfers torque by friction not the shear strength of the boots the important thing is to remember and check the bolts for tightness after the first run and again after 500 to 1000 miles.


Yeah I know that but by having higher strength bolts you can use a bit more tightening torque which gives even more friction coupling. I also used loctite to reduce the chances of coming loose but also check the bolts at each service. Bottom line for me is that these bolts are pretty important and I'd rather buy 10.9's from an ISO certified supplier and be sure that they are 10.9 than use 8.8's which, depending on the source, may or may not be up to spec. Same thing with steering linkage bolts and any other critical fastener. Peace of mind never came so cheaply... ;-)

renetom - 2/2/14 at 07:55 AM

Hi
got my prop to Sierra diff bolts from Ford
10.9 supplied

Prop bolts Sierra
Prop bolts Sierra