skratch77

Just got my car back and I'm puzzled why the transmission shifts like butter.its legit like a new car and it cant be just from new diff oil can it?

there is like no telling the car is shifting in s and s+ just driving normal.

my old differential had 39k on it and probably the original oil but man this thing shifts so damn smooth now and its 7 degrees out on top.

ps if you don't' have a lsd it is by far the best feeling after getting it.the best way to describe it is like there is another 1000 lbs in your trunk and feels so much tighter and solid.

Jasonoff

Maybe your old dif had excessive backlash.

chrisridebike8

It could have also been the flex disk worn out. Did they replace that when the new diff went in? Any kind of play in the diff mounting or the driveline would have made the car feel clunky.

Celicasaur

That's the first thing that came to my mind when I read his post.

skratch77

All we changed was the differential and used the rest of the old stuff and swapped over.

I think there was excess backlash or the oil made the difference but the car shifts like it got a new transmission now.

the biggest difference is shifting with light load.

Celicasaur

Had you ever reset the tranny adaptations before? I wonder if that might have been the one...?

When my valvebody was rebuilt, it still wasn't all that amazing until after a couple of weeks of normal driving....after that point, it started to shift like butter (ie, the way it should be shifting) and it's been pretty good like that ever since in terms of shift smoothness.

Either way - I'm glad you're happy and it's working nicely for you now

deadlyvt

Could be the temperature too..I drove mine the other day -5 degree Celsius and the shifting, engine responsiveness and power where the best it's ever been

Celicasaur

The problem with that though is traction. Or rather, the lack of it. I can't do anything exciting in my car nowadays. I promised myself that I'd get winter tyres this year, but I cheaped out again

Vladds

Who did the work, the dealer?

skratch77

I use a speed shop near me that does all my work.i cant imagine what the dealer would charge for this.

Celicasaur

Skratch...do you have a spare diff casing laying around? Can I have it please?

skratch77

I'm going to list it as a whole to try to recomp some money out if it.

I thought the c63 had a bigger diff anyways?

Celicasaur

Damnit.

But oh, i thought they were the same, no? At times like this we need Vladds and his cool MB info thingy.

Hmm....I need a spare case really...I'll try eBay then

Vladds

I'll look it up in a minute.

Edit: I just remembered that I looked at diffs overall part numbers and there are quite a number of them, let's see if the housing number stayed constant. What I am trying to say is that there were probably 2 PFL non LSD, 2 LSD, 2 FL non LSD, 2 FL LSD and then a black series.
Edit again: This is a mess, they have codes for remanufactured diffs and for your turned in cores.
Sadly no diff internals are sold, but housings are sold separately. A termination is added to the part number that is not in the STAR, which can signify new, remanufactured or core for the same part.


Also, if you had the dealer do the diff swap (I would pre-negotiate the price of the work of course), you could have them variant re-code your car, to now include the limited slip option, which ..... could... increase its resale value.

skratch77

I got that backwards! I think the e63 has a bigger diff.

I paid 300 all in for the diff swap.not sure what the dealer would charge but they want like 600 for a transmission flush.

Celicasaur

Thanks Vladds - I look forward to it sir

Also, FWIW my car has the P30 package, which on the W212 meant having an LSD, the nice 19" forged wheels (which I've totally ruined on kerbs) and an engine with as much power as a stock C63


Skratch - if you're thinking of the ring gear - it' the SL model that has the bigger diff (and possibly the CL). I'm pretty sure The C, CLS and E have the same size.

Vladds

Look, try A 204 350 47 14 -80, this seems to be the housing number, the rest is a salad of misc. differentials and cores and remanufactured diffs.

Due to all this complication, I'm not 100% confident, but it seems that the housing could be the same at this part number. I would take this part number to a dealer and ask if they can confirm if this is the only housing for all C63.


Hmm, let me try reverse by seeing which cars they sell this for in the online vendor sites. Yeah, the description is E63 without LSD housing and they would want your core. Nah, I pulled the part number from the C63 and I don't see a housing number LSD only, but, I'm not 100% sure.
Then again, the part number of the housing should be visible from the outside...

Celicasaur

Thanks Vladds - I'll maybe get under the car this coming weekend to replace an exhaust gasket and then take a look at the diff for a part number then and report back.