I’m planning on changing my transmission fluid next week in my 1993 300D with 203k miles (W124 with a 722.418 transmission). The fluid and filter were changed recently (3k miles ago) so I’m just planning on doing a drain and fill to put in some Pennzoil High milage ATF and some Lubegard Red.

I’ve read the forum a lot trying to collect all the info I need (in addition to the service manual I have) but still have a few questions.

1) I was planning on using ramps to rise up the Benz but I’m wondering how I’m going to turn the torque convert to get to the plug without raising the back wheels? Do I need to jack up all 4 wheels using jack stands?

2) I was just turning the torque converted with a big screw driving, will this work?

3) What size tools do I need? I know that I need a hex for the torque converter but I don’t know what size. What size do I need for the removing the engine compartment lower panel? What about the drain plug itself?

4) Any additional “gotchas” I might need to know about specific to this Benz’s ATF change?


Thanks,
Paul

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1993 300D 2.5 Turbo Diesel - 201k miles

I turn the TC by bumping the starter (key) and checking, it isn't scientific but it works.

My auto-trans friend cautions against draining the TC and having a dry start, seems the best method is not to drain it and have dinner or go to bed, but to refill and start reasonably soon.

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Gone to the dark side

- Jeff

Well, MB says to drain the TC, that's the only way you can get all the old fluid out.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Okay, perhaps I was unclear. I mean drain it, but don't leave it drained overnight. If possible, plug it and fill it shortly after it has drained.

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Gone to the dark side

- Jeff

The reason that you car has a torque converter is to allow the engine to operate while the drive wheels are not turning. You don't need to raise the rear wheels.

Sorry, I just don't get it. Fluid and Filter changed 3K ago, so why bother changing to some alledgedly better fluid, and some allegedly helpful additive. Use the specified fluid and change it with filter at 30K. That's all.

But if you insist, then yes, screwdriver works. Be careful to only rotate TC in the direction of normal engine rotation. No, rear wheels don't have to be off the ground ( think - car in neutral ).
If you drive the thing up on ramps it really restricts your access, no?

Steve

Well I'm having some classic aging transmission issues that the highmilage stuff might help (or slow the impending death) so I'm willing to give it a try. For a complete history look here: Transmission history, maintenance and how should I proceed?

As for the ramps, so would you suggest using jack stands? I've never climbed under a car this low before so your suggestions are welcome.

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1993 300D 2.5 Turbo Diesel - 201k miles

Ramps should be fine for transmission service.

In most cases it's 4mm hex for the torque converter and pan drain plugs, 8mm socket or wrench for cover panels.

Ramps will do fine.

Paint a line on the crank pulley visible from above when the torque converter plug is at its lowest. Next time you change fluid, you can turn the engine from above to locate the drain plug.

How about Mobil 1 ATF instead of additives?

Sixto
93 300SD 3.0

I've always been cautioned about synthetics in older cars because of seal issues. How do you think Mobile 1 would benefit me and the issues my Benz is having?

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1993 300D 2.5 Turbo Diesel - 201k miles

Mobil 1 is fine, I've changed cars over when new, when 245,000miles, and anywhere in between and I've never (sound of knocking on wood) had an ATF leak.

It's an old rumor, had to do with the chemistry of synthetics in the '70s, long since changed. The official word from M-B back when I was getting the magazine was use synthetics, if it leaked already it might leak more with a fluid that doesn't get thick when cold, so switch it back if you don't like the leak.

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Gone to the dark side

- Jeff

I haven't had leak problems switching 3 high miles 722 transmissions to Mobil 1. YMMV. Shifts feel a little smoother and definitely more consistent throughout the fluid temperature span. Smoothness could just be new fluid but I didn't notice the consistency improvement when changing non-syhtetic ATF with non-synthetic ATF.

My basic point though is what is your confidence that Lubegard will not do more harm than good.

Sixto
93 300SD 3.0

The car could be in any gear, the torque convertor and engine would still turn.

I guess I can't know either way until I try.

Do you know of issues it has a history of causing?

I do know that Lubegard Red is spoken highly of and its my understanding many car makers endorse its use.

I did see that Wal-Mart had Mobil 1 ATF for a little under $6 a qt, that's much cheaper then I thought it might be. I'm still open to using it if I truly understand it's benefits over the Pennzoil High Mileage ATF. I'm looking to have something help my tired old seals and I'm told the thicker High Mileage stuff will help.

Again I have no personal experience in this all.

Paul

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1993 300D 2.5 Turbo Diesel - 201k miles

Do you guys torque the drain plugs for the pan and the torque converter?

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1993 300D 2.5 Turbo Diesel - 201k miles