I've read a few DIYs on it but I'm still nervous. I really messed up a Jaguar X-type tranny a few years ago when I didn't quite understand the sensitivity of auto trannies and fluid levels.

I noticed my electrical connector o-ring is leaking tranny fluid so I bought the new connector part and figured hey... I might as well drop the pan, change the gasket and filter, and replace only the fluid lost during that. It will dilute the old fluid and, with a new filter already in place, I'll be good to just do pan drains every 5K miles for a few times to get most of the old fluid out.

I bought the filter/gasket/drain plug washer, o-ring connector, tranny fluid and dipstick tool for the '04 SLK32 basically.

I plan to check my level by shooting the pan with an infrared thermo, though that isn't the official right way to do it. It seems a lot of people have had success that way though.

So if anyone has any tips to make me feel better about my upcoming task then please share.

 

The O-ring was a TSB and even if your out of warranty should still be a dealer warrantied item. In the owners manual I believe it says the tranny never gets serviced or not at least for like 100k miles. I'll look again when I get a chance.

 

Yes the manual says some long term time, but then Mercedez released a TSB for the 722.6 trannies saying 39K miles, and then never again for life.

I was just looking for some tips or motivational words on the procedure...

 

You Can Do It!!!!!

 

You're the man!!

 

To check the fluid I used a length of speedometer cable ( before they had electronic speedos N. Tesla had designed a moving magnetic speedo driven by a flex cable). [Yeah the group is named after that Tesla, and the international unit of Magnetism is named a tesla, Gauss got bumped on that one.

The cable easily snaked down the tube and bottomed to the pan, giving me a good dip stick. I measured a distance of fluid of 3.66" from the bottom up, FYI. The IR gun will not sense thru aluminum for two reasons. First the heat line and the resolution of the heat gun are not too precise. Two: You can not measure shiny (natural finish) metals due to low emissivity errors. If you wanna measure metal spray it with paint or place a layer of tape on the surface to accurately sense the temperature.

Thermally yours, Woody

 

Woody, what are you saying? That you measured before and then matched the level after? I'm not following....

I bought the dumb over priced dipstick, but am curious what you're saying. Because if the infrared on the pan isn't going to work then I'll need a good piece of advice in the next day!

 

You can check with Splinter, but the fluid level is checked from the bottom of the pan, and up. Mine read out as 3.66" as a level. Check Splinters posting about level checking, Enjoy Woody.

 

If you have not found it yet I think this is what Woody is talking about......https://www.crossfireforum.org/forum...smission+fluid

 

Oh right. Yeah, thats why I bought the dipstick. But I have to make sure I'm at a certain temperature before reading the level. Thats where the infrared shot to the pan comes in. How did you check your temps before reading the level?

Im figuring scan tools are expensive for doing this, unless theres some basic one for a hundred bucks that I can't seem to find.

 

Hey guys..

I drained the fluid today. I DID NOT drop the pan and change the filter. My plan was to drop the pan and change filter, and doing 3 more pan drains afterwards. I bought enough fluid for that. And, after that final 4th drain, enough of the fluid will be new that I can sleep at night.

Well, I didnt feel comfortable dropping the pan so I just did the drain and fill and will drop the pan on the next one in a few weeks. Remember my story: I ruined the auto tranny on a beautiful Jaguar X-type by not being careful on my fluid change. I had always owned manual trannies and I just didn't realize the improtance of fluid choice and fluid type. (It was 4 years ago, I was only 24 and fresh out of college). This is why I'm so scared to touch auto trannies today, and its why I ditched the Jag for a 'dumb design' Mustang GT that was basically impossible to mess up. But I'm back baby!

So, some notes:

1. At 28K, the fluid was brown. Not nearly black, but certainly not red. It was a healthy brown. I believe it was on par with the Mercedes TSB about changing the fluid in these trannies at 39K. I can picture it being still brown, but thicker, in 11K miles.

2. The pan drain bolt was insanely hard to remove. It had to have loktite on it. I had to use a long breaker bar to break it loose but I was terrified I was going to just break the bolt head completely.

3. Don't freak out about the lock tab on the refill plug. Stay calm. Its easy to remove just study it first and pry it out. Its not way down behind the engine like on some Mercedez (I think) its instead extended and right there by the battery. Breathe.

4. My plan was to shoot the pan with infrared to measure the temperature while measuring the fluid. Before doing this I instead used an empty liter oil bottle and poured the old fluid into this. Each filled liter of the old fluid meant 1 new liter of new fluid poured in. It was very accurate and made me feel better. Then when I was done I did the warmup in drive, shot the pan, checked at 80 celsius. It measured right below the correct area, not even a millimeter. I said forget it, I'm done. I'm draining and refilling in a week or 2 anyways. Overfilling is worse than underfilling so I"ll stick with this.

So, thats my story. I'll update this thread the next time I do it assuming I do the pan and filter also, which I'm almost sure I will.

 

Excellent job.

There’s no sense in anyone being intimidated by maintaining the transmission himself. As long as the correct fluid is used along with the requisite specialty tools and the utmost cleanliness is observed during the procedure, you’ll be rewarded with increased service life and far better shift performance.

MB originally insisted that our 722.6xx transmission had a “lifetime” fill. That was only the case when scheduled maintenance was included in the purchase price. Now that those marketing wizards have been given the boot and sound engineering has once again prevailed, 39k mile/three year ATF fluid and filter replacements are once again specified in their service regimen. If you’re trading up before its warranty expires and your conscience allows it, they’ll easily go 50,000 miles with no attention, save for the TCU connector’s O-ring.

Although we have no torque converter drain plug as shown - some worthwhile pictures here:
http://www.mercedesshop.com/Wikka/Trans7226Fluid

I’ve twice flushed my ATF in its entirety; it’s not difficult for any reasonably competent DIY’er.
A bro's well documented procedure – if you’re so inclined:
http://forums.mbworld.org/forums/sho....php?p=2739493

MBC32RadiatorRR14-1.jpg

 

Special Tool 8863A

Seen in this drawer:

 

I purchased this one for $30.00 Reads from -20C to 520C

http://www.harborfreight.com/cpi/cta...emnumber=96451

 

Yes I bought one from Sears. But I don't trust it. Metal heats up slower than the fluid inside, and it cools down slower also... Another thing, the pan shows a good 8 degrees more on the engine side of the pan as it does on the further side.

I had to take a guess... After a nice 25 minute drive I was probably looking around 80c, since 80c is generally as hot as a tranny will get, besides spirited driving getting it up with 88c-ish, so I just checked after a good long drive.

I'm going to order a OBDII tool for it, but the current options don't support tranny temps. scangauge is getting close, but they don't yet support chrysler/mercedes trannies.

 

IR guns do not work well on metal, try to measure a shiney metallic surface to prove this. I spray paint a spot to sense, to get the temperature correctly. Barring that thought, I use a spot of masking tape to provide a reliable black body like surface to measure/detect.

Shiney surfaces have bad emissivities and give wildly variable readings. FYI. The temperature reading is also 'the average' of the surface so dont try to sense a 1/4 spot, their focus is too diffuse for that precision.

Chillin, WOODY