What torque for my 4.2 E-Type Harmonic Balancer Nut?

I’ve just bolted the sump back onto the block, with a new front oil seal.
The engine is still in the car, and (after reading the posts on this forum) everything went like a dream.
(- so far that is…we won’t be celebrating until it runs with no oil leaks).

For the life of me I can’t find a torque setting for the big nut that holds the harmonic balancer onto the crankshaft.
There is a post in the XJ40 section of this forum for 185-220Nm (140-160 ft lb).
Which roughly translates to bl…dy tight!

Should I wind mine up this tight?
Does anyone have any better info?
Thanks in advance.

I usually go 120lbft.

For what it’s worth - the V12 calls for 125-150 lb.ft. for tht bolt

I just looked at my Bentley manual and the Haynes Manual. Neither mention a torque value. And after a very brief search I see nothing in the archives. hopefully, an experienced e3ngine rebuilder will chime in

Thanks Gentlemen.
John, thanks for opening the manuals, much appreciated.

I’ll pull it up to 120 as Andrew suggests.
It’s getting it’s locking tab back, so I’m pretty comfortable it won’t fall off.


Feel entirely comfortable: in 50 years, I have never once seen a crankshaft pulley nut, properly torqued, ever come loose!