Mercedes-Benz Forum banner

1 - 20 of 48 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
Hello BenzWorld, I have been having this issue with my 1990 190e 2.6 that has a 5 speed swap. I swapped the transmission and differential years back and the car drove great. More recently I had pulled the engine and trans and the car sat for about 2 years before I had new seals put into the transmission and the head gasket done to the m103 engine. After taking my time putting this thing back together I now have this random violent clunking that happens very inconsistently. The car made similar noises when my flex disc went out year back but I have new flex discs and new motor mounts in place. After a week of not figuring out the problem, I took it to a shop where they immediately diagnosed bad rear subframe bushings. I had them go ahead and do the job and they installed strongflex polyurethane bushings. After the expensive job ($1500) the car drives better but the loud clunk from the rear end is still there!! I am certain that the noise is coming from the rear end. I am starting to believe that the differential is making these noises. The differential from what I am told is an lsd from a sportline. The differential never made these noises prior to the engine and trans being pulled. The clunks happen sometimes when deaccelerating and also between gear shifts but it is hard to replicate the noise on command. The clunks do not cause any driveability issue but it sounds like bolts smashing into each other in the bac and have no idea what it could be. I have checked the bolts everything seems nice and tight. I am replacing the transmission mount tomorrow to see if that helps. If anyone has any ideas please let me know. I can send pictures or give any details if needed.
Thanks, Joaquin
 

·
Registered
1989 190e 2.6
Joined
·
226 Posts
I've been chasing down the same. Originally mine was quite bad with quick throttle changes, that clunk went away with a change in diff. I still have a clunk on some gear shifts and occasionally off throttle. Odd to hear that subframe bushings didn't solve it as that was my next suspect.
 

·
W201 Moderator
89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
Joined
·
2,713 Posts
I'm pretty sure it comes from the differential itself. I stated this before in some other posts.
Mine started around year 2000, 100K miles. The dealer insisted it was the flex discs and changed them. It was not.
The clunking got worse over the years and it also whines now in 5th gear with no load. (so strictly diff speed related).
It is some sort of play in the diff. You can jack the car up and make it "clunk" by rotating the wheels. So certainly not a sub-frame bushing issue. Though the bushings may muffle the clunking sound a bit, the source of the noise is not the bushings.

Car now has 195K miles, so it is just a nuisance and I have learned how not to "clunk it" when I'm shifting.
If I find a newer differential from an automatic I'll swap it in. So far, I have seen a lot of auto-diffs in the JY's that are in better shape but not good enough to pull the trigger.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #4
I'm pretty sure it comes from the differential itself. I stated this before in some other posts.
Mine started around year 2000, 100K miles. The dealer insisted it was the flex discs and changed them. It was not.
The clunking got worse over the years and it also whines now in 5th gear with no load. (so strictly diff speed related).
It is some sort of play in the diff. You can jack the car up and make it "clunk" by rotating the wheels. So certainly not a sub-frame bushing issue. Though the bushings may muffle the clunking sound a bit, the source of the noise is not the bushings.

Car now has 195K miles, so it is just a nuisance and I have learned how not to "clunk it" when I'm shifting.
If I find a newer differential from an automatic I'll swap it in. So far, I have seen a lot of auto-diffs in the JY's that are in better shape but not good enough to pull the trigger.
Thanks for the reply I think you might be right. Just took the car to a different shop where we lifted the car and were able to rotate the driveshaft more than a quarter turn before the axles started turning which I now suspect that it is the diff as both of you have mentioned. I got the diff used and it is a limited slip from a sportline I was told which is hard to source here in California.

Next step is to look into getting the diff rebuilt, or sourcing another lsd. Another option I will look into is swapping an lsd from an m3 (e36 maybe). I really appreciate the wheels being synced especially when I get on it from a stop. Does anyone know of any differential swaps that fit good in 190's?
 

·
Registered
Joined
·
25 Posts
Discussion Starter #5
I will probably just deal with the clunking until the differential gives although I do drive several hundred miles frequently. Is this a bad idea?
 

·
W201 Moderator
89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
Joined
·
2,713 Posts
As I said my car has had it for 20 years / 100K miles. I do not know how bad yours is and if it is really the slop in the diff.

Perhaps measure it at the wheel by jacking one side up and rotating the tire. Measure at the outer rim of the tire.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #7
Mine started all of a sudden. I will probably just live with it for now. With the car in neutral, it was pretty easy to rotate the driveshaft and if done so with enough force it creates that same violent clank coming from the differential. I did a little bit of research on other possibilities for the rear end. Going to source some preferably another LSD but I also read about an ASD that came in some 190's and also w124's. If I source an alternative I will probably hold on to the current differential I have and hopefully one day get it rebuilt.

Check out this link about other possible differential swaps:

 

·
Registered
Mercedes-Benz
Joined
·
1,310 Posts
Sportline came with same open diff as the other W201s. Not sure about ROW cars, but that's at least true for US market. Easy way to test for open or LSD is if both wheels turn same direction when turning one manually when both wheels are up. Also if your speedometer reads accurately and it wasn't changed when you did your diff swap, you have an open diff as there is no 2.87:1 LSD.

My diff has a slight clunk that I only notice when changing direction from fwd to reverse or sometimes when on-off power in reverse. Didn't make any noises when car was auto that I recall. I've gotten more used to it as time has passed since the swap to the point is doesn't particularly bother me much.

Easiest option is to install a Wavetrac diff if you require an LSD.
 

·
Registered
Joined
·
174 Posts
I got adjusted for collecting parts and emptying my wallet. Least resistance is my goal and assuming your front end suspension is in good shape (alignment, shocks) I myself would break out the lube (Moly long life - smells like cut grass interestingly). I put Royal purple in my differential and there was an immediate change for the better. Pack the front wheels caps with lube and I don't care if the cv joint boots are quality Mercedes rubber or not, grease will oxidize and turn to something like mud. Did you give thought to your inner CV joints? Pull the axles off and shoot some grease in the joints that you do not have to remove the snap ring for it from each end. I am guessing your brake pads are good/No binding rotors. Is your brake system needing to be bled for air? I went thru the gamut with this and then found out that my tensioner rod had separated in two and from the idler pulley assembly. My fail was not loosening the center bolt and testing after adding my New belt. I got a clunking noise at takeoff and thought it was the flex disks and inspection proved these parts in good shape. Please see my culmination at:


Charlane
 

·
Registered
1989 190e 2.6
Joined
·
226 Posts
I replaced my diff about 9 months ago, I can tell you there was zero internal play with it off the car, nice and tight and yet still have the clunk.
 

·
Registered
Joined
·
174 Posts
There is an easy way to test for that blasted tensioner rod and just grab the flange nut and pick up on it and see if it moves freely. And I mean like loose. It won't pull out, but just flop around.

Charlane
 

·
Registered
1989 190e 2.6
Joined
·
226 Posts
There is an easy way to test for that blasted tensioner rod and just grab the flange nut and pick up on it and see if it moves freely. And I mean like loose. It won't pull out, but just flop around.

Charlane
Sorry maybe I'm missing something, what does the tensioner rod have to do with rear end clunking?
 

·
Registered
1992 190 e
Joined
·
74 Posts
I have the same issue with my new to me 5 speed sportline (USA). There could be a quick fix. There is a lock nut that that locates the the pinion gear to the ring gear as well as sets the backlash of the diff. The lock nut is located in the yoke. So, detach the yoke from the drive shaft and check for end play. You may get lucky and eliminate the clunk by tightning the nut. Depends on how much wear in the differential.

Also, I would put some good Moly gear oil in too.

The manual transmissions put more torque on the drive train the the autos do.
 

·
Registered
Joined
·
174 Posts
Sorry maybe I'm missing something, what does the tensioner rod have to do with rear end clunking?
Resistance. So you saw my name and that means I have no experience. All I can assess is that the drive belt would bind and then quick release making something of a clunking noise at take off. It ran a little rough also and after everything else I did to it. I put a new belt on and then the next problem jumped out. I worked on a few MBs and domestic cars, too. It's fine with me however you take this. Luck to you!

Charlane
 

·
W201 Moderator
89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
Joined
·
2,713 Posts
I have the same issue with my new to me 5 speed sportline (USA). There could be a quick fix. There is a lock nut that that locates the the pinion gear to the ring gear as well as sets the backlash of the diff. The lock nut is located in the yoke. So, detach the yoke from the drive shaft and check for end play. You may get lucky and eliminate the clunk by tightning the nut. Depends on how much wear in the differential.

Also, I would put some good Moly gear oil in too.

The manual transmissions put more torque on the drive train the the autos do.
Do you happen to have some schematics that show/identify these parts?
Does the diff need to be out of the car to do this work?
 

·
Registered
1992 190 e
Joined
·
74 Posts
I hard loud clunk? Bearly noticeable noise? A constant whining?

I have no drawings. Check out the attached videos. You should be able to check if the nut is loose without taking out the differential. Just something to check before going to the expense and time consuming repair or replacement process.

The carrier bearings could be worn too. Different problem.

I would also drain the oil and check for wear debris. If there is a lot of metal particles in the oil you are on borrowed time. If you wanted to get real fancy you could sent a sample of the gear oil out for analysis for wear metals.

Hope this helps.


 

·
W201 Moderator
89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
Joined
·
2,713 Posts
Very educational, thanks Dave. Would be nice to pull one from the yard and work on it on the Bench.
I'm pretty sure my issue is too much back-lash.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #20
Thank you!!
I hard loud clunk? Bearly noticeable noise? A constant whining?

I have no drawings. Check out the attached videos. You should be able to check if the nut is loose without taking out the differential. Just something to check before going to the expense and time consuming repair or replacement process.

The carrier bearings could be worn too. Different problem.

I would also drain the oil and check for wear debris. If there is a lot of metal particles in the oil you are on borrowed time. If you wanted to get real fancy you could sent a sample of the gear oil out for analysis for wear metals.

Hope this helps.


This might just be it I will check tomorrow afternoon when I get the chance but that video helped a lot and seems like identical symptoms that my car is having! I hope just the tightening of a nut will fix my problem.
The LSD has a small plate where the bolts go on the cover of the differential (I will attach a picture tomorrow) which I was told it is an LSD and it certainly has been operating like one no more one wheel peels. I bought the LSD used from someone who had planned on doing a 5 speed swap, the speedo was certainly off showing speeds slower than I actually was doing before the cable stripped out which is another thing I need to fix before the milage is considerably off.
Thank you all for the replies I will keep you updated!
 
1 - 20 of 48 Posts
Top