Transmission fluid and filter change

[JWJ]

Is there a how-to on changing the transmission fluid and filter?

How difficult is the job?

The search feature comes up with nothing obvious.

Thanks

[Hit Man X]

Comically easy. ~5mm allen for the drain plugs (drain the converter too, have a few beers while it drains) and 13mm for the pan bolts.

I find one of those goofy 90° offset screwdrivers works best to remove the filter, should be three screws. Drain old filter well and recycle it too. Should hold about 6-7tq of DexIII. Only additive I trust is LubeGuard.

Also, perfect time to drain the motor oil for a change and rear diff.

[Jom W124 300D]

it wasn't that easy for me cause of the torque converter had to be rotated to the right spot to get at the drain plug.
In my 603, not much room up front to rotate crank- ended up (in neutral) jamming a screwdriver into bell housing and rotating driveline (ALWAYS clockwise - from front)
ya gotta be VERY clean in there too! No sworf from rags to be left over. Or dirt.

That rear diff plug is TIGHT too and needs a VERY beefy 14 mm allen key.

Hit Man- am I seeing things or do you have eleven cars!!!????

[Hit Man X]

The converter drain is a PITA like no other. Best to have someone rotate the motor over at the crank while you peek up in there.

I ended up using some heat to crack open the diff plugs on one of the cars.

Yeah, I have to stop buying. I need to get a few put together totally and given away to family. 3-4 of them.

[JWJ]

None of my factory manuals has anything about the transmission. Why is this?

Is the torque converter plug obvious to get at?

When I attach the gasket to the pan and trans bottom do I need to add anything on it to seal it? Or is it just pan, gasket, attached to trans.?

Thanks,

JWJ

[cgunderm]

check out these explanations with pictures. nothing on torque converter, you need to buy his DVD to get that, but the rest is pretty nicely described.
i need to do my 124 soon. i think i'm going to do the "flick the key method" to get the tc in the right place....

[JWJ]

I think you forgot the link.

[cgunderm]

you are right. sorry. here it goes...
http://www.dieselgiant.com/mercedestransmissionfluidchange.htm

[JWJ]

Great! Thanks! That's almost everything.

Anyone got a photo of the torque converter?

So I know what to aim at...

[toomany MBZ]

Torque converter is located just in front of trans, there is a support brace with a "window" showing a finned aluminum thing. This spins with engine, need to roatate to find drain plug. DG should pic.

[Richard Eldridge]

When I changed the AT fluid in my cars, I refilled it with Mobil-1 synthetic, on the grounds that the fluid will be in there for a long, long time, and I might as well use the best.

It's readily available here in Miami, but when I had my sister's Taurus tranny redone in Kansas City, I could not find any Mobil 1 Transmission fluid in two hours with the yellow pages.

Mobil 1 makes gear oil for the differential, too. It smells just as funky as the petro nonsynthetic stuff, which was not what I expected.

[F18]

Originally Posted by toomany MBZ

Torque converter is located just in front of trans, there is a support brace with a "window" showing a finned aluminum thing. This spins with engine, need to rotate to find drain plug. DG should pic.

You can rotate the converter with a flat head screw driver through the housing "window" using the window for leverage. It moves the converter pretty easy clockwise until you can visibly see the drain plug.....no need to screw around with ratcheting the crank bolt up front. You won't damage the converter....it has a tough steel or aluminum body. Been doing it that way for years!

[JWJ]

What type and size tool is best to remove the torque converter drain plug?

[toomany MBZ]

Originally Posted by F18

You can rotate the converter with a flat head screw driver through the housing "window" using the window for leverage. It moves the converter pretty easy clockwise until you can visibly see the drain plug.....no need to screw around with ratcheting the crank bolt up front. You won't damage the converter....it has a tough steel or aluminum body. Been doing it that way for years!

Cool, I'll try that next time.

[toomany MBZ]

Originally Posted by JWJ

What type and size tool is best to remove the torque converter drain plug?

Afraid you'll just have to look and see. If you have metric tools, I'm sure you're set. Got to be an off the shelf deal.