cpbeasley

I posed this question in my other thread regarding my proposed "pumpkin" swap, however it was brought to my attention that an interchange between any w203 may not be possible due to changes throughout the years of the generation. Since the traffic to the end of that thread may have been limited, Im hoping to get some new eyes and help on the question.

I'm ready to swap a lower ratio rear differential into my 06 c350 @ a 2.83.

3.47 and 3.67 are the lowest available as OEM pumpkins. The 3.67 is the most desireable, found in the early c240s. The 3.47 I have found in a c230k as late as 05. I believe the switch to the 2.5L m272 precipitated a lower ratio in the 06 and 07.

I need to know what differences between the pupmkins I need to phsyically be able to distinguish so that I will know if the donor pumpkin can be a direct interchange candidate... or not.

This came as a surprise from splinter, as I was under the impression all the rear diff's were physically the same minus the ring gear/pinion inside.

Not knowing any better, I would asume the 3.47 would be a better candidate as it came in a facelited 05, versus an older say 2002 3.67 from a preFL c240.

Thank you

cpbeasley

I've got this question up at peachtree, going to speak to the guys at Potomac to see what they may or may not know, i have no faith in any service tech to know so i wont bother calling the dealer...
considering i found the 3.46 out of the 05 with only 21k miles for ~$300, I may be forced to pull the trigger on that due to fears around the pumpkin out of an old c240 being the most likely to not swap in place... and the fact the c240 3.67 is going to have the most # of miles.

someday when I have a more endless supply of money I'll get the Quaife LSD setup and have a custom ring gear and pinion made instead of 3.07 found within the c32 diff.

anyone have any help to offer, any resource/person for me to contact?

W203E35

Just ship your car to Jeremy and let his buddies at Gintani Supercharge your car.

OneOfaKindTrini

Kleeman also offers a LSD, but it has to be special ordered and it retails at roughly 800Euros plus shipping.. Not cheap.

OneOfaKindTrini

Or Tuning Technologies Motorsports.. They have a STAR computer

cpbeasley

waiting on Karo to supply some star screenshots re: the gear change so i can help my local mb service techs do their job, lol.

W203E35

I'm doing it now. Will post in couple of min.

cpbeasley

someday ill get my hands on star, but not sure i could learn how to use it! feel like i'd have to learn german to garner its full potential.

supercharger maybe someday if i got bored with the N/A. I really wanna squeeze everything i can out of it with cams, headers... and then before i screw with the heads and compression id make the choice whether or not to go forced or stay all natural

W203E35

We have a problem. The STAR Simulator doesn't let me see the ECU variant coding so I can give you screenshots and I can't hook it up to my car because recently the multiplexer has been blacklisted. These couple of days I have been trying to figure out how to unblacklist it. Give me couple of days so I can figure it out if not then I will reinstall STAR or use a program to see what recent file changes have been made (blacklist file has been put on the system).

cpbeasley

wow. how did tht happen!?

So there's no way to even supply some directions w/o screenshots? (im assuming not, blacklisted is a word i equate with eff'ed)

W203E35

I can show you in developer mode but the dealer doesn't have developer mode. When your using STAR with a chinese clone multiplexer and your internet is on it checks with MBs database and says "hey hold on a sec..this isn't an original multiplexer and it stops your multiplexer from working. It can not write on your multiplexer so I'm guessing it puts a file or writes a code in DAS/SDS so it doesn't work.

W203E35

Here is how to change the gear ratio in Developer Mode...(Developer Mode FTW!!!!)

LILBENZ230

Dear Karo,

Please come to GA.

Sincerely,

Matt, Trey, Drew, MW_Atl, and the rest of the east coast gang.

MW_ATL

I really need to get one of those.... Or you need to come visit!

havoc_vulture

im sort of oblivious to what is happening in this thread DX
does this mean that the diffs can be programed to the desired ratio?
OR
that our cars can be programed to support such differentials when replaced?
sorry for sounding naive C:

cpbeasley

Now to find a developer mode.....

one of the SAs at the local dealer is a corvette tuner independently, maybe he'll sympathize and help me out. otherwise, im buying you a plane ticket brother.

if you figure out a way around your blacklist thing, via the way any dealer can do it, im definitely listening.

thank you special K!!

cpbeasley

Karo-

Called dealer. They can get access to developer if they need to. They call MB and get a password to enter that mode. The shop foreman said he had done this a couple of times in his 8 year history there, lol.

So I guess ideally we'd find the way to do this without developer, correct? If have access to developer, then what is the other part of star called that was blacklisted that you dont have access to? Is there a way to do the ratio change in your now 'blacklisted' mode? (sorry dont know what its called)

Ive got a PM out to Johnand maybe he has access to what you dont?

Ive also got a call out to the shop thats doing the gear swap. Hes checking with his partner if they know someone with star.

W203E35

Hey did John ever get back to you? Did you get the details to do this? Have you asked the dealer if they know how to do this?

rcompart

I just want to point out that changes to this setting have NO effect on your ability to run a lower rear gear as the programming for the rear gear needs to be hard coded in the trans controller or the car will code up for implausible gear ratio and trans slip. I've been working with Marcin on getting this figured out on the 5-speeds but I don't want to see you spend money on the diff and then not be able to use it.

Good luck and take care

W203E35

Thanks for the heads up. So this has to be coded directly to the TCU?

Edit: You think his manual will throw codes too?

cpbeasley

John never got back to me.

I have no further details than what you gave me. But im hoping what you gave me is all i need

The dealer has never done this before and has no idea but said they would follow your screenshots in developer mode and see what happens.

I really need John to get back to me, ugh.


EDIT: John got back! Developer is the only mode where an option exists to change ratio! woohoo!

cpbeasley

RCompart,

fortunately, my 6 spd manual doesn't have a trans controller, and last time I checked the only slipping inside a manual is from the clutch, so I dont share the worries you do with your auto-box.

Good luck to your efforts, however my 6 spd is ready to march on

tommy

At today's price, that's $1,075, which ain't too bad. The Quaife on my CRX retails for more than that.

Anyone here done the Kleemann LSD?

cpbeasley

does it fit the smaller non-amg ring gear/pinion or is for the larger amg equipped differential?

rcompart

That is very good to hear and was something I neglected to notice until you pointed it out (6MT). Stick that bad boy in there and have at it! Should make the car a more pronounced at the line.