Gordon Gecko

Well I blew out the differential in the Black on a trip to Road Atlanta this weekend ( no I didn't track it - went to watch the Petit Lemans)

I told the dealer if the MB's can't take the thrashing I will go back to Ferrari's!

The dealer - MB of Buckhead- has offered to install a locking diff in place of the stock for an extra $1500 or so. Has anyone else had this done and can share their experience?

Many thanks

R

LOVEMYBS

Please explain "locking differential?' All BS's come equipped with a limited slip differential. Is that what you're referring to?

jrcart

The dealer is trying to screw you, there is no $1500 "locking" dif available for these cars, as the other poster just stated the Black Series comes with a LSD from the factory, to the best of my knowledge there are no after market difs available for these cars...and if there were it would run you more than $1500. I contacted Quaife a little less than a year ago to inquire about a one of their rear-ends (just for a back up in case something did break) and at that time they had nothing available nor anything in the works for the Black Series.

You are the first person I have heard of to break the rear-end on one of these cars, lots of us have significant gains in HP and torque and regularly track them and have never heard of any problem so the fact that you broke your on a joy ride on the road tells me there was certainly some kind of a factory defect. Get it replaced under warrany, let us know the exact point of failure within the rear-end and tell the stealership to screw off on their "locking" dif modification.

ATL_MB

I think that the $1,500 is incremental to the stock unit - so, $4,500 or so?

The LSD he is referring to is a Wavetech diff. Basically, its a Quaife-type diff with CF wafers sitting on top of one another that as the diff slips ride up on each other and press the gears together to lock it up. I have it on my C63 and its a pretty good unit. I would say, though, that for that money I would just get an OS Giken. You need extra diff cooling for the Giken unit to last, but the BS diff has it already, so you should be good to go.

DFW01E55

I'm under the impression that the C63 and BS have different gear ratios.
Have you changed yours?

jrcart

Not only different gear ratios but entirely different splines and axle receiver diameters, nothing is able to cross over from the C63 to the CLK BS and vice versa unless you are talking about swapping housings and axles as well.

Gordon Gecko

First the dealer suggested I consider the true locking as opposed to the ltd slip that is stock because the warranty pays for labor and stock so why not consider while it is all apart Second I just got this three weeks agp and there was a loud knock from th rear upon 2nd and 1st downshifts. So may have been abused as a child. Wonder if the lack of blipping tears it up. Wish I cld get it to to downshift mire quickly coming into a turn hot. Miss my fcars and manuals sometimes!

jrcart

Trust me these things can take abuse, definetely more than any F car can.

AMG Dictator

Just get another stock one under warranty.

LZH

I agree with everything Jim said - please make sure your dealer tells you EXACTLY what failed in the dif and pass it along here...you are the first person on here that has been able to break the rear end, which is very odd considering others here are putting alot more power to the ground with no driveline failures. The stock unit can handle quite a bit of abuse and I'd venture to say that whomever owned your car before you beat the hell out of it....or, you simply had a defective unit.
Tell the dealer to just install the stock dif under waranty. As others have said, there is no locking dif available for our cars, nor would you want one. A true locking dif would ruin the driveability of the Black Series.

Jim Brady

Gordon G
Sorry to hear your bad experience. Can you be more specific on "blew out" did it break gears, or overheat causing it to seize or what?

As JrCart said some have but insane torque and hp through these drive trains and no problems.
I know many like the "Quaife type diff" to be something special due to the gear vs clutch applications. I raced a Quaife diff porsche and they can break! I was at the factory and the question came up how stout was the rear end, the answer was with proper run in it's near impossible. So I guess you did the impossible.
If you look at the old Tommy Kendal tests of the P9000 prototype you can see the beating the car has taken on a track. with no problems.
Jimmy

SMP

In the other thread you mentioned going to the Petite Le Mans race and smoke was coming from the rear end, and on your way back home the gears made a grinding noise. LOL, no wonder that you "blew out" your differential. They are not designed to run without oil.

Even if you can find an aftermarket unit, when you run it without oil the same thing will happen again.

ATL_MB

No, I did not change the ratios, and did not mean to imply that I had or that the C and CLK diffs are the same. I just meant to say that I know that MBOB is selling the Wavetech units and that I have one in my C63.

Gordon Gecko

Well there was some oil leaking from the diff onto the pipes on the way up to Road Atlanta but short of checking the dipstick and since there is no warning light pertaining to diff oil and it stopped I drove on then limped home

I appreciate all the input. You guys are great. I will revert when I get a prognosis. I think the true locking diff for an extra $1500 even if it exists is prob not worth it. Wld rather get an ECU upgrade

LZH

I noticed the same thing in the other thread...I'm suprised this is occuring on so many vehicles. Didn't RAGE2 just have his diff almost blow all the fluid out?? I guess this is something we as owners need to keep a closer eye on and service more regularly
My service A is due in a week and I plan on having my dealer change the dif fluid and inspect it for any excessive metal shavings...

rage2

Yea, you can't miss it when you lose the oil, it's a HUGE smokescreen like a blown motor. I lost 3.5 out of 4L of oil in the diff. Difference was I towed my car to the dealer right away, didn't drive back. Oil was topped up and the diff is fine so far. No weird noises.

Dealer says it's either the diff was already low on oil (thus overheating) or the sensor is broken which didn't turn on the pump to the cooler, but they're not sure because there is zero technical information in Canadian dealerships.

Was hoping someone knows what that sensor does, or know of a way to test it. There's no MB dealerships in Montana, and the closest one is in Calgary for me.

LZH

Rage - if you get me a part # on that sensor, I'll have the shop foreman at m dealer get me more info on it as well as make sure mine is working correctly. I'm pretty sure it a thermostatically controlled switch for the fan extractor that circulates the oil thru the cooler. Perhaps that what happened to the OP and his switch failed causing the dif to grenade??

DFW01E55

There was supposed to be a complimentary diff oil change at 1,000 miles.
You guys may want to check the service records and see if it was done.

LZH

I've done mine 3 times in 12k miles. The first one at 1000 miles was done for free as you said...but I've heard of some dealers trying to charge people for the 1000 mile change.

rage2

I'll get that for you once I'm back in Calgary. I left the car there, and I'm in the US right now.

EURO.SPEC

I would suggest Having it repaired under warr, after warr runs out, I would highly recommend an OS Gekin being that I've installed 6 of these units at RENNtech,. They are extremely tough, flush lines, coolers and pump and use only OS Gekin fluid. This unit is a 100% locking unit.

LZH

Is the Gekin unit an LSD or a true "locker"?? Also, I do not see any Mercedes applications in the Gekin site....

jrcart

Very odd indeed, 7000 hard miles, countless hard laps on road courses with wide sticky rubber and literally hundreds of passes at the drag strip running nitrous that bumps me up to over 650rwhp on drag slicks, if I have not found the breaking point of this rear-end there is no way a low key "Sunday Drive" to Road Atlanta should have popped yours. I'm sticking to the theory that there was a leak and it got run dry or close to dry.

SMP

I don't know how many previous owners the car had, whether the LSD was properly broken in and serviced at the factory recommended mileage. When I brought my car in for the LSD oil change, the dealer had the right gear oil in stock, but not the hardware, which had to be ordered from Germany and took a couple of days to get here. I guess some dealers just used the old parts instead, or the customer forgot about it and the LSD was never serviced. Either way, whith a low oil level and some aggressive driving, the LSD overheats and spews the rest of the oil out the overfill. Without lubrication or any cooling, the gears and clutches will literally eat each other.

RBYCC

Correct me if I'm wrong, but a true locking differential inhibits a vehicle from cornering at anything but a very slow speed....

LSD is the proper application for a vehicle that needs to go around a corner...