SH || NC

Thanks to Dell I was able to quickly and painlessly change out my 2004 C4S tranny fluid today. Used the Shell stock fluid. CPO w/ ~42k on the clock.

Not hard of course, but what was interesting was that the drain bolts are magnetic from the factory, AND, the front bolt had much more particulate accumulation that anticipated.

The rear diff fluid was a honey or amber-ish color - much better than I expected after seeing rotokim's 99 almost look like used motor oil. I am assuming it was his original fluid, and while he had less mileage, his is obviously ~5 years older.

There was a little dusting of ferrous material on the rear drain plug even though the drain plug sits vertically, so it much be magnetic from the factory. I do not know if the rear fluid had even been changed before, but it certainly looked to be in better condition than the front. No pictures.

The front diff fluid was murkier, more cloudy, with lots of sediment on the plug. This is the drain plug just after it was removed from the front diff.





Here is is after I tried cleaning it out. The plug is actually hollow with a magnetic rod in the middle. The entire cavity was filled with ferrous material. I wiped it off and used Brake Kleen to try to force some it out. This is how I left it.



FYI, no drivability problem, sounds, or leaks since I've had it since late October, just wanted to to a drain and refill for possible added longevity of the transmission and diff, and peace of mind.

Anyway, food for thought. I cannot imagine going 90k on the stock fluid.

springgeyser

On my other AWD commuter car, it was 'hopping' at near full lock at the 70k mark. I changed out the center diff fluid and the 'hop' went away.

I actually need to change all the tranny/diff fluid on my C4 also. Finding the time is another story.

roadsession

For this reason - I am getting the fluid change done today at the dealer...(@55K miles but car is 8 yrs old and in heavy stop/go traffic)

SH || NC

roadsession

btw: dealership tells me drain and refill is around $250 (not bad) but with filter change it's around $600... so I'm just going with drain and refill...

LVDell

road....do you have a tip? If so, I'm not sure what all is involved but if it is the same amount of fluid that Scott used, then $75 worth of Shell and $175 in labor doesn't sound "too" bad from a stealership. But what filter are you referring to? ATF filter?

roadsession

yes - Tip S... And yes they quoted me $600 to do filter, orings etc...or $250 for just fluid. My local dealer (Herb Chambers Porsche Boston) was pretty straight with me. My SA said that with 50K miles on the clock I should be fine with just a fluid drain and refill and at 100K miles go for the whole filter / oring change... (BTW my local INDY quoted $300 for the fluid change!!!)

he also said that he's never seen the Mercedes transmission fail on the Tiptronic S (which he said is used on the AMG cars and able to handle excess of 600ft lbs of torque), but that the Mk1 tips have been known to fail....He also quipped it's one of the many things in the 996 that has been over-engineered and over-built. I asked him what else is over-engineered and over-built - he said in general the H6 engine is pretty much over-engineered and over-built if compared against many other engines out there. His point is that many owners do DE's on these engines and daily driver them. No other engine in his experience could handle that kind of use and survive 100K+ miles.

I then couldn't help but to ask him about IMS. The master tech was there in his office. They both said that it is VERY rare, and a much more common mode of failure they've seen on the engine is intermix. SO ....anyway....