Hi,

The door-locks on my 85 740 are not as smooth as they used to be.. What's the best thing to use on the lock mechanism ? The hinges too are a bit squeaky, so want to fix that as well.

Thanks !

Noel

I would recommend against spray lubes in locks unless they are absolutely
immovable. All spray lubes have a solvent in them that helps to penetrate,
but then evaporates leaving a thicker lubricant. This is OK for doors but
not for locks. My best success on locks has been to use 3in1, Sewing Machine
Oil, etc and put it on the key a number of times until the key has carried
enough of the oil into the lock to get to where it needs to be, working the
key each time.

If the lock is gummed up, carburetor cleaner will dissolve the gum but leave
the lock completely unlubricated so you need to get some oil in there after
cleaning it. Carb cleaner is also hard on paint, sound deadening panels, etc
so you might want to put a rag around the lock to catch it so it doesn't
drip inside the door. You gotta take off the upholstery panel to do this.
--
George Downs, Bartlesville, Oklahoma, Central US

I would advice against oils like WD-40. Even if they have great penetration capablities, they tend to dry out too quickly. My own personal favourite is white lithium grease on spray can, the brand I use (CRC) comes with a "straw" for pinpointing.

For locks and lock mechanisms, some people prefer graphite powder, as oil can gum up the smaller parts. I have used both and can't really say I have noticed any difference.

Erling.
--
My 240 Page

Use a high-quality spray lube on the lock cylinders and mechanisms. Use some rear axle oil or engine oil on the u-shaped springs on the hinges.