Tools Required for a W126
 

If I was to invest in a set of tools for common DIY repairs, what range of sockets, wrenches, hex heads, etc. would be recommended to cover most of the car? Most of the sets I'm looking at include 1/4" 3/8" and 1/2" drive sets with certain sizes missing - some include deep sockets, etc. Any suggestions?

Get metric tools for sure. Most of the nuts and bolts you're likely to handle will be covered by a set that includes 8, 10, 11, 12, 13, 15, 17 and 19. A set of standard sockets, deep sockets, open wrenches, combination wrenches (open on one end, box on the other) should be plenty. get the sockets in both 3/8" and 1/2" drive to the extent that they're available.

To drive the sockets you'll want a rachet handle and breaker bar handle as well as an assortment of extensions. My u-joints don't get much use. I much preffer wobble extensions. And a torque wrench, of course. I find the 'click' type easier to use than the beam type (needle on a scale). Most MB specs are provided in Nm so make sure it has that scale or a dual scale (with lb-ft).

Depending you what engine you have, get a socket to turn the crank. I think 27mm is what most MBs use. Only a really big tool set will have a socket this big.

I'm not mentioning generic tools like screwdrivers and pliers.

I'm sure there are a lot more tools you'll find useful based on what you do and how you like to work. A tool set is a good place to start, then buy the other pieces you need as necessary.

Sixto
91 300SE
81 300SD

If it's an SD, you might want the Hazet tools that make adjusting the valves so much easier... and a set of feeler gauges, of course.

There's also special spark plug sockets that have a rubber piece that holds the plugs. My spark plug socket won't hold a screw tip plug (as opposed to a knob tip plug). Gosh, I don't even remember if MBs use 5/8" plugs or 13/16" plugs. If it's an SD, you won't need a spark plug socket... unless it also works on glow plugs.

Sixto
91 300SE
81 300SD

Sixto - Thanks for the help. Its a 420SEL, and you're right about the 27mm for turning the crankshaft.

I was also planning on buying a set of hex heads - what sizes do you use?

Does anyone have any experience with Harbor Frieght tools? (www.harborfrieght.com) They're very reasonable - compared to Craftsman.

A 14mm hex head(allen head) may come in handy for draining the differential.

5 mm allen for tranny/torque converter fluid drain. Also, 10mm allen for engine mount(300SD) 420?

10mm allen also used for removing front rotors from hub.

Thanks for the help - what is the recommended service interval for differential fluid??

Also - what brand of tools do you guys use/suggest?

On hex bit sockets (is that an oxymoron?), Craftsman has a set that goes from 5-10mm without 9. You might find a 14mm hex bit socket at Napa.

There's a special tool for the head bolts of the M116 and M117 engines. It's an 8mm hex bit at the end of an extension with a joggle in it to clear the cam.

Sixto
91 300SE
81 300SD

Some at this site have said that Auto Zone carries a set of larger allen heads for the differential. I believe it includes 12mm, 14mm; 17mm. The 14mm is not sold at Sears, Home Depot, or other such places. I got mine from the Snap-On guy B4 I heard about the Auto Zone option.

It may be overkill, but I change my differential fluid once a year along with the tranny fluid and coolant. Fluids 'n filters keep the beast alive.

Mike - are you able to drain the torque converter, if so, how? How difficult is it to change the differential fluid? I've never changed diff fluid before. What type of oil is recommended?

The question was directed to Mike but I'll give the torque converter question a try. Rotate the engine clockwise as viewed from the front until the torque converter drain plug is at the lowest point. There's a hole at the bottom of the bell housing for this. Don't forget a new washer for the drain plug.

Sixto
91 300SE
81 300SD

To add to Sixto's good advise....

Use a 27mm socket on the end of the crankshaft to rotate the engine in order to position the torque converter drain plug(also 5mm allen head socket). Before you can actually see the torque converter drain plug, there's a cross-member like piece that must 1st be removed as it blocks access to the torque converter drain plug. It's held in place on both sides by 3 - 17mm bolts. The torque converter drain plug and the tranny pan drain plug use DIFFERENT washers. One is silver; the other a copper color. I forget which is which.

You'll use the 14mm allen head mentioned above to drain/change differential fluid. The drain plug is the lower of the two. Be sure to first loosen the fill plug(the one on top) first. You don't want to drain the gear oil until you're certain you can refill it! I perform this procedure on a fully warmed up vehicle so as to get a good drain of the fluid and as many contaminants as possible. Once drained, I reinstall the drain plug, then refill through the top hole. I take a LONG stretch of heater hose and connect a plastic tube on one end(secure with hose clamp), then route it up towards the top of the right rear tire. On that end, I connect a funnel, then pour the the gear oil in through the funnel. If you're having trouble getting the 14mm allen heads loose, back the car up a bit on ramps so as to provide more room for increased leverage. Once loose, bring it back down to level ground.

Had a 6-month contract in Colorado Springs, and I bought an 86 Chrysler Conquest to tool around in for the duration. Didn't bring any tools back from Texas, so I bought what I needed at Harbor Freight store there.

I have some socket wrench sets and 4 jackstands from Harbor Freight. I am pretty happy with the quality, and the prices were reasonable.

G-Benz - did you notice any difference in quality from Home Depot or Craftsman tools? What tools do you have in TX?