Where's the torque convertor drain? - PeachParts Mercedes-Benz Forum

firemediceric · #1 04-19-2007, 05:18 PM

I wanted to drain the torque convertor along with the transmission pan. From everything I've read, I should find the allen head drain plug behind the plastic shield on the front of the tranny on my 1981 300 SD .

I removed the plastic cover and after having no success turning the engine with the power steering nut (yes, it's in neutral) I "bumped" the engine trying to find the drain plug. It never did show up. The battery is probably toast from how often I "bumped" the engine.

All I ever saw were some hex head bolts. Out of desperation, I removed them to see if maybe one of them was used to replace the allen head plug. No luck.

So why am I not finding the drain plug?

tangofox007 · #2 04-19-2007, 05:32 PM

Look on the outer perimeter of the torque converter. When the drain plug positioned at bottom dead center, the plug should be in a vertical position, with the head facing down.

rrgrassi · #3 04-19-2007, 05:33 PM

Bumping the engine can spin it too far. If you look at the tranny housing where grid plate metal is, there is an opening that lets you get to the TC drain. Have the engine spun by hand until you see the allen head.

toomany MBZ · #4 04-19-2007, 06:04 PM

Quote:

Originally Posted by rrgrassi

Bumping the engine can spin it too far. If you look at the tranny housing where grid plate metal is, there is an opening that lets you get to the TC drain. Have the engine spun by hand until you see the allen head.

There you go. Using a helper is much eaisier.

firemediceric · #5 04-19-2007, 06:13 PM

Quote:

Originally Posted by toomany MBZ

There you go. Using a helper is much eaisier.

If only the dog had opposable thumbs.

From what I am reading, you guys are saying that rather than removing the plastic plate and looking straight into the bell housing as a post by Samual Ross advises in an old thread, I should be laying on my back and looking straight up at the bottom of the transmission and look for the drain plug through an access hole?

I did see two holes underneath that I though may be access holes. The one to the left of center has a bolt that passes horizontally through the hole. The one to the right of center has an allen head bolt. I put a long 5mm allen wrench into the hole and removed a really LONG bolt. No fluid came out, so I put it back.

DrewGerhan · #6 04-19-2007, 07:20 PM

I have heard that if the tranny was rebuilt at any time the new torque converter might not have a drain plug. i just used a 1/2" rachet and socket on the crank bolt and turned it little by little untill I found my drain plug.

patbob · #7 04-19-2007, 08:17 PM

It's not behind the little plastic cover.

See picture #3 from this writup I did (http://www.hevanet.com/patbob/MercedesK1SpringKit/SpringKitInstall.html) from when I replaced my K1 spring kit.

I've heard the bump it with the starter advise, but after doing it myself, I don't see how that's likely to work. It only takes being off by about +/-10 degrees to miss the plug so you can't even see it, and a lot less to have it unaligned with the hole so you can't get a wrench up there. My torque converter had scratches on it from the screwdriver someone used to torque it around.. I used a breaker bar and socket on the crankshaft bolt. Had to go around two revs as I missed it by a few degrees and didn't want to turn the engine backwards.

hope that helps.

firemediceric · #8 04-19-2007, 09:42 PM

Now that you guys have pointed me in the right direction, I guess tomorrow I'll try to look in the right place.

JimmyL · #9 04-20-2007, 12:12 AM

From a post in another thread..... This is technique sensitive, but it works.

Quote:

Originally Posted by JimmyL

Gave up on the AC leak for today!!
You never really know, but the old fluid actually looked very good. Excellent in fact. But I bought the wagon a year ago, and you just never know.
I also had to replace the two short flexible lines right at the radiator, which was my major leak of the car. Also, I started off by going to spray wash and spending 75 cents on cleaning off underneath the car. Recommended.....
Took almost 3 hours, but I'm an obsessive cleaner and tend to piddle around when doing things. The pan was spotless. Completely. One thing different on this wagon than the '80 wagon: you could spin the torque converter with a screw driver on the '80, but NOT the '85. I used somebody's advice: Socket on crank pulley with ratchet pointing down. Right foot on left front tire, right hand (both hands sometimes) on ratchet, and eyeballs on torque converter looking for drain plug. Works perfect! The T.C. draining makes quite the mess, as it "glugs" the whole time. I love the MB gaskets, and let me say one thing. The gasket for the six bolt pans is 100% easier to place and stay than the 4 pan bolt trannies. It's a gasket like the valve cover.
Went with a Mann filter, 2/3 bottle of TransEx, and Mobil 1. 6 quarts and it appears to be about 1/2 qt low, but it's all I had for now.
Not at all hard to do, and can be done much faster than I did it today. I was just killin time and enjoying the day.

guage · #10 04-20-2007, 01:26 AM

Once you find it then take one of those white or yellow permanent ink/paint
markers and mark the bottom of the harmonic balancer so it's much easier to find the next time.

Use that mark to find the drain plug, not the harmonic balancer

andmoon · #11 04-20-2007, 03:53 AM

On my 6th tranny fluid change I lucked out and the drain was at the bottom!

firemediceric · #12 04-20-2007, 12:21 PM

Patbob,
That link was great! The tip on getting on socket on the crank shaft bolt was one of the best tips I've gotten. I wish I had that knowledge when I did the valve adjustment.

Getting the right information instead of incorrect direction made all the difference in the world!

racerx12367 · #13 04-20-2007, 05:23 PM

You can also use the power steering pulley to turn the engine, its alot easier to get at. Turn it clockwise.