I could have put this in the 'What Have You Done To Your Range Rover Today" thread but thought that this deserves a dedicated post.

I changed the oil on my P38 yesterday & was confused regarding the torque setting for the sump plug. It's listed in RAVE as 45 Nm for up to 99MY & 32 Nm for 99MY onwards. The sump is the same & so is the sump plug so why the difference? I think that it must be due to the different crush washer. Originally the crush washer was copper then was replaced with an aluminium washer. My engine has just been rebuilt by V8 Developments & had a copper washer on the sump plug. I replaced it with a new copper washer & tightened up to 45 Nm so I hope that I have done the right thing.

The sump isn't the same. Pre-99 GEMS has a pressed steel sump but a later Thor has a cast alloy one (which incorporates the flywheel cover rather than it being separate) which probably explains the difference. I've never seen anyone use a torque wrench on a sump plug, most people just do it up tight......

Gilbertd wrote:

I've never seen anyone use a torque wrench on a sump plug, most people just do it up tight......

Bounces up and down.

"Me, me, me".
Set rather lower than factory theory too. Always anneal copper washers. Even if brand new.

Especially on alloy sumps. Don't know enough swear words to properly express my loathing for rethreading sump drain holes when Gorilla Garages Inc have hauled the plug up to one micro-newton short of stripping so the verdammn thread comes out on the plug. Sorting out a repair bush thread compatible with the OEM plug can demand a certain malevolent creativity.

Clive

I never use a torque wrench either. I usually use a short ring spanner on plugs like that rather than a socket set which has a greater risk of over tightening.

Gilbertd wrote:

The sump isn't the same. Pre-99 GEMS has a pressed steel sump but a later Thor has a cast alloy one (which incorporates the flywheel cover rather than it being separate) which probably explains the difference. I've never seen anyone use a torque wrench on a sump plug, most people just do it up tight......

That does explain the difference. I had thought that the changes between GEMS & Thor were all at the top end & wasn't aware of the differences in the sump. I too wouldn't normally put a torque wrench on a sump plug but had noticed the the difference & thought that it might be important. Presumably the copper crush washer is for the steel sump & aluminium one for the aluminium sump?

I wouldn't put my beautiful shiny torque wrench in the way of that filthy old engine oil... but I don't gorilla them either. Just a "nip up" which is, as we know, the correct technical term.

Presumably the copper crush washer is for the steel sump & aluminium one for the aluminium sump?

I think this is correct assumption, because my mates' GEMSs :-) have copper ones and my Thor has a alu one.
Obviously by the time we started taken care of these, many oil changes have gone by, but I think previous hands have certainly neglected that little aspect ....