The drivers window on my 450sl will not come down..It
moves approx 2 inchs down and then stops..QQQ

first check of lose smal stone blocking window channels, (or other protuding part in channels), then spray wd 40 into door interior (and mechanisim thouroughly) work window up and down to its limit, if you are lucky, iwill work full lenght. Did for me, good luck, Abe G

Take the door panel off to start with. It isn't a big job and if you start farting around spraying this and that lubricants (Note' WD-40 is NOT a lubricant so don't count on it lasting) you are just going to end up with a messy window that probably still doesn't work.

When you remove the panel slide a thin piece of metal down the side until it hits the little tabs that hold the panel to the door frame. The best tool for this is a small pry bar called a Wunder-bar. They make a small one, about 6 inches long, but any size will do. DO NOT try to PULL the panel off. You will pull the tabs out of the Masonite backing and probably break the paneling in the process.

Once the panel is off all problems will become evident. You can remove the two bolts that hold the wildow to the regulator (the two cross arms that move the window up and down) and slide the window up. There may be some binding in the track. If it moves freely then the problem is either in the regulator or the motor. As I remember I think that the motor comes out farely easily. With it out you can test it (use a battery charger for a power supply) and move the regulator manually.

If all the above fails then you need an entirely new car because yours is obviously possessed by deamons.

I would not have made the suggestion to first use WD 40 before disassembling anything if it did not work! Over the last 5 years, I have used this spray to restore operating window mechanisisms without one disassembly. WD 40 is a penetrating lubricaant and if used regularily (every 6 months orso) can keep mechanisims free and operating properly. If a motor or other mechanical fault exists thats the followup. Save yourself a headache, at leat first TRY my suggestion. Sometime a good fart can do wonders! Abe G

I have been doing mechanal work for 45 years on everything from lawn mowers to 40,000 hp super tanker engines under fire off shore Iran and do not dispute the advantage of penetrating oils in certain situations. Having repaired more than my share of car windows I realized the disadvantage of blindly spraying WD-40 or its ilk into the inside of a door hoping that some few drops will find their way to the problem. Not only will you waste a lot but it also can impregnate the upper seal and make it track oil onto the window each time you roll the window up. What time you save by nottaking off the door panel you will spend by cleaning the window. Any car that is 25 years old and having trouble with the windows should have the door panels taken off, the regulator cleaned and greased, the drain holes in the bottom of the door cleaned out, the bottom of the door checked for rust, the electric motor and gears checked, and the door opening and locking mechanism cleaned and greased. It is an hour well spent.