Mainshaft Inboard thread type

[pete.collings]

Can someone confirm (or deny?) that the thread on inboard side (locating against the flywheel) of a VH drive side mainshaft is Right Hand. The timing side mainshaft has a left hand thread in a similar inboard position (or so I believe).

I have tried to undo a TS mainshaft nut without success, warming it beforehand, and before I go to more forceful methods, I would like to know I am actually trying to undo it! I seem to recall removing a TS mainshaft a long time ago, but don't remember having this level of difficulty with it. Any suggestions (apart from taking to a specialist) on tricks to utilise when undoing these nuts and removing (and replacing) mainshafts much appeciated.

I have searched the forum and knowledgebase, but have not found anything covering this specific topic.

[Simon.Gardiner]

Hi Pete !

I sit here with a pair in front of me - drive side right hand thread, gear side left hand thread.

I tend to put the flywheel in a vice (use soft-jaws, bits of scrap ally or even paper if worried about 'bruising' the flywheel) and use a socket with a long extension bar (old Matchless fork legs are good for this!). And getting the nut really really hot beforehand (ie 'sizzling spit' hot) will help.

Putting them back together, again flywhell carefully but firmly in a vice but don't need anything like the same force as the nuts aren't very strong and shear at quite a low torque (about 25 ft lbs from memory, hopefully someone out there can help with the exact figures).

[nevhunter]

Mainshaft nuts are LH on timing side and RHand on the drive side. Knowing which hand gives more confidence. They shouldn't be ridiculously tight. Although the thread is quite short I would think that tensioning to around 50 ft/lbs would be required and I would consider a bit more if doing what Wal does. The nut needs to be made of something decent, and a good thread fit. They do a big job. ensure no burrs anywhere and that the tapers fit well with the key in place. (DS).. The nut faces must run dead true or they will tend to make the assembly run out of true. Nev

[pete.collings]

Thanks for the replies, I will have another go at undoing the nuts later in the week, with the help of a friend and a long socket extension.