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#1 Torque setting for alternator driveshaft nut
Posted: Sun Jul 06, 2014 6:37 pm
by ALAN COCHRANE
Hi Everyone
Does anyone know what the torque setting is for the nut on the pulley wheel shaft of a Lucas Alternator. When I took off my faulty alternator I was surprised how slack the nut was. You can't trust a mechanic to do anything properly-oh wait that was me!
Cheers
Alan
#2
Posted: Sun Jul 06, 2014 10:27 pm
by abowie
Like most of these things you probably won't find an exact figure in the manuals.
It should have a spring washer under it; I did mine up tight (not effing tight) with an ordinary ring spanner and I usually use Loctite for things like that that rotate quickly.
#3
Posted: Mon Jul 07, 2014 10:26 pm
by ALAN COCHRANE
Thanks for the reply Andrew. The only figure I could find was 25lbft which can only be a little more than finger tight by my reckoning.
I'll keep searching but like you I'll probably just give it some welly with a standard ring spanner.
Alan
#4
Posted: Tue Jul 08, 2014 1:40 am
by PeterCrespin
" The only figure I could find was 25lbft which can only be a little more than finger tight by my reckoning."
What reckoning is that then Alan? Your handshake must be a bone-crusher
Find something that weighs 25 lbs - like 11 bags of sugar or a modest weight flywheel. Not insignificant. Then put a foot long ring spanner onto a small nut and rest your heavy weight on the free end. That is not trivial torque. The drive shaft flange bolts aren't tightened a lot more. Even the big end nuts are only in the mid thirties.
"I'll keep searching but like you I'll probably just give it some welly with a standard ring spanner."
Why keep searching? 25 sounds a perfectly reasonable number.
Andrew strikes me as a scientific sort of chap and not given to wellying a ringy with abandon. Tightening torque is dictated in large measure by the dimensions of the fastener. It's not a huge nut...
I've practically never used a torque wrench except on major fasteners. There are advantages to messing with mechanical stuff more or less non-stop for 45 years, amongst them a calibrated forearm. Mine starts down near the wrist at 'finger tight' through 'hand tight' to 'snug' then 'firm' and along a range of settings up to Andrew's 'effing tight' near the elbow. The upper arm (farm machinery torques) and shoulder (railway equipment)remain un-calibrated and Shipwright's Leg, as applied to 6 foot open enders is a sight to behold I'm reliably informed... Not so much foot pounds as foot pounding, whole body jumping etc. :D