Hello,

please advice tightening torque for following bolts:
Between flywheel and gearbox bell and bolts for fixing gearbox case to engine block.

 

Gear case to bellhousing 58 to 65 Ft/llbs. Use loctite

Flex plate (flywheel) to crankshaft 66Ft/llbs max. But you must use the locking ring tabs and loctite

Flex plate to torque converter: 35 Ft/llbs Use Loctite!

 

And isn't it nostalgic (for us Brits) to see that British Leyland logo on the block!

Paul

 

Thank you Greg,

What about 3/8 bolts fixing gearbox to engine block ? I believe 58-65 is too much?

 

this gearbox is TH400 and have integrated non detachable bell-housing

 

Indeed, but the workshop manual only gives that number and no alternative number for the TH400. You may well be right (the bolts are going into aluminium, after all). Maybe someone else can give more info?

 

Greg,

I've just checked a couple of workshop manuals in the sections that describe the installation of the V12 gearbox with integral bellhousing. And despite it stating to do up the bellhousing bolts, and also quoting all the torque figures at the end of the section for the various figures, it doesn't seem to ever detail a figure for "engine to bellhousing bolts" or "engine to gearbox bolts" etc. That seems quite strange?

Also, and forgive me if my memory is fading, I thought in your own gearbox removal thread, you mentioned that the 9 bellhousing bolts were 9/16", not 3/8" as stan73 has mentioned? Or did I misread that?

Paul

 

Agred on first point Paul. In my WSM it gives the torque figure of 66 ft/llbs for the box to bellhousing (the original BW box I assumed) and I (quite possibly wrongly) assumed that the same would be for the TH400 as no different figure was given. It would be intersting to know if anyone has a definitive figure; although decently tight plus loctite will be fine in any case, I reckon.

The bolts (except the top starter bolt) have hex heads requiring a 9/16ths socket size, you remember correctly. Maybe the OP was referring to the barrel diameter, but I do not know whether that is 3/8ths?

 

Greg,

I've just found something in one of the later w/s manuals (TH400 era) where it says

""Clutch/ torque converter housing to block 49-54 NM"

So that sounds like they are describing the overall gearbox to engine connection for a TH400, wouldn't you agree?

Paul

 

Sounds like it Paul. 54nm = 40 ft/llbs. Sounds fine to me.