Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
2001 SLK320
Joined
·
134 Posts
Discussion Starter #1
Does anyone know whether the SLK320 and SLK230 share the same differential? The one in my 2001 SLK320 has been whining at high speeds, so I've found a good (warrantied) used one from a 2000 SLK230, just want to confirm whether it will work?
 

·
Moderator
1998 SLK 230
Joined
·
2,650 Posts
i would have to check on WIS to confirm but the housing is the same BUT i think the gear ratios are different for the v6 and the inline 4. if you put a diff in with different gear ratios car will just go into limp mode after a certain speed as it throws sensors off unless you correctly re-program the trans computer.

SLK230 -> SLK230 should be fine... SLK320->SLK230 prob not. ill confirm later.
 

·
Registered
2002 C230 Sport Coup and 2006 ML350
Joined
·
1,127 Posts
I had whining, was certain it was the diff, but turned to be the tires.
The ratio's are stamped on the outside of the DIFF.
Also, there's bushings on the drive shaft that can cause noise too.
If you don't get the correct ratio on an auto the ESP will get fouled up.
(did they have manual for SLK? It doesn't care what diff ratio you use)

How many miles? Are you certain it's the diff?
I've learned it can be so many things...got my mechanic to take a ride, he's the one who said tires...in fact I think he said that because it wasn't making noise at all speeds.
Also wheel bearings...
I'm at 190K miles and diff is still good.
 

·
Moderator
1998 SLK 230
Joined
·
2,650 Posts
agreed... the diffs are almost bullet proof and i doubt its failed... tripple check thats the case before you buy anything.

attached is the WIS documentation on both diffs. only difference is the SLK320 ring gear is larger. ratios remain the same
 

Attachments

·
Registered
2001 SLK320
Joined
·
134 Posts
Discussion Starter #5 (Edited)
Thanks guys, that WIS document really helps. I would be going 230 to 320, so would I need to source a replacement (larger) ring gear?

I wish it wasn't my diff, I guess I am just one of the lucky few who ended up with a faulty one. Car has only 127,000kms, one prior owner, all mercedes service history, never raced or abused.
The dealer checked it out and suggested tires, so I tried two other sets (including a brand new set off my brother's SLK230) and the tires made no difference. I started doing some research and found a handful of people with the exact same symptoms, most of which occured at very low mileage and were eventually diagnosed as a faulty diff.

Here are a couple threads

http://www.benzworld.org/forums/r170-slk-class/1441102-differential-whine-slk-320-a-2.html

http://www.benzworld.org/forums/w211-e-class/1474153-differential-noise.html

80 mph rear end noise and the dealer - CrossfireForum.org

Humming noise when driving over 50 mph!? - CrossfireForum.org

Symptoms

The diff whines while maintaining a high (115km/h+) rate of speed with my foot resting on the pedal. As soon as I lift my foot even a little bit (thus removing tension from the driveline) the noise disappears instantly. The noise is loudest at 130km/h, beyond that speed it begins to fade.


As an aside, I filed a complaint with Mercedes Benz Canada, explained my car's history, service, and directed them to the threads above. Yesterday they sent me a confirmation that they are investigating a possible resolution for me.....So I will have to wait and see what MB comes up with before buying anything myself. I am impressed that they didn't just dismiss me right away given that the car is 11 years old, but I am still not getting my hopes up. I will report back and let you guys know what they come back with.


BTW: Is there any other Mercedes that would use the same diff as the SLK320? Maybe the C or E 320?
 

·
Registered
2002 C230 Sport Coup and 2006 ML350
Joined
·
1,127 Posts
That's unfortunate. There's a contingency of 2002 M111 powered C Coupe owners, who call themselves the broken diff gang.
I guess I'm lucky. Crossing my fingers. Didn't dump the oil the 1st time till 120K miles.
Likely due again.
 

·
Registered
2001 SLK320
Joined
·
134 Posts
Discussion Starter #7
Well, I MB has arranged for me to take a road-test with the shop foreman at my local dealer. Service manager called me today and said that once the shop foreman confirms it is the diff, we could "talk about the possible options". My road test isn't until August 7 (shop foreman is on holidays) so I will provide another update then.

While I am waiting on that I would like to try my luck sourcining a direct replacement diff (with correct ring gear and everything); can anyone tell me if a C320, E320, CLK320 (or other?) would have the exact same diff?? SLK320's are very rare around here, almost all of them are 230's in my area.
 

·
Registered
'01 SLK230 & '97 328IS
Joined
·
121 Posts
agreed... the diffs are almost bullet proof and i doubt its failed... tripple check thats the case before you buy anything.

attached is the WIS documentation on both diffs. only difference is the SLK320 ring gear is larger. ratios remain the same
Subby,

Is the diff from an SLK320 an LSD?
 

·
Moderator
1998 SLK 230
Joined
·
2,650 Posts
Non of the slks have a LSD diff even the slk32 to achieve LSD type results they do it electronically via traction control to shift power from one wheel to another via applying the rear brakes not mechanically with a LSD clutch in the diff... I'll check later to see if the e or c class ones are a fit and post back
 

·
Moderator
1998 SLK 230
Joined
·
2,650 Posts
attached are the specs from WIS for the C class and CLK class. the E class ones are different gearing inside and ratios

so this confirms technically they are OK but mounting wise? not sure. i cant see it being different as its for the same package engine/trans combo. but need to confirm 100% say on EPC (electronic parts catalog) which i think USA residence have access for free online?
 

Attachments

·
Registered
2001 SLK320
Joined
·
134 Posts
Discussion Starter #12
Thanks Subby! That is a huge help.
I actually spoke to a very knowledgeable Indy today (setting up my plan B if MB doesn't come through with a decent resolution), who confirm that the CLK320 is a direct swap, but the C is not, the housing is different.

I tired to get into EPC, but as a Canadian resident - no dice.
 

·
Registered
2001 SLK320
Joined
·
134 Posts
Discussion Starter #13
Had the appointment with the dealer today, expected disappointment and I guess that'd what I got. Shop Foreman drove the car and agreed that the issue is likely the differential, but he wouldn't answer me when I asked about whether it was indicative of failure or not.

The Service manager just seemed bothered that he had to deal with me at all; insisted the the whining was just the gears meshing and not indicative of failure. He also indicated that MB would not offer to cover any costs, nor would he be able to guarantee that any work they do would resolve the noise. He said he would look into my repair options (rebuild, new, etc) and call me by the end of the week.

I understand these guys are out to protect themselves, and the best interest of the dealer, but this doesn't really sit right with me. I knew getting MB to cough up anything would be a struggle, but this business about not guaranteeing that any work they do (ie replacing or rebuilding the diff) would resolve the noise sounds like crap to me. Wouldn't one expect that the dealer should have sufficient technically skilled staff to properly diagnose and resolve ANY acknowledged issue?

I am going to wait till he calls me back so I can understand the options and costs they're presenting. Then I'll likely push him a little and see where we can get. Does anyone know if working directly with the dealer/service department is the best way to go, or should I try to work this through MB headoffice?? I originally contacted H.O, but they directed me to the dealer.
 
1 - 13 of 13 Posts
Top