Fluttering noise on acceleration 86 560sl - PeachParts Mercedes-Benz Forum

DanielG · #1 08-21-2003, 09:50 AM

I posted this in the SL forum -- with limited results. Sorry for the double post, but if anyone has some insight into this problem I would appreciate hearing from them.:

For some time I have been hearing a noise in my 1986 560sl. It occurs in the right rear of the car during acceleration. It sounds like fluttering and occurs only at acceleration from a stop -- seems to get louder as the acceleration continues -- but does not seem to occur at other accelerations (such as when passing other cars or accelerating to higher speeds).

At first I thought it was the muffler, and as I had been told that it had a small hole, I went ahead and had it replaced. When I continued to note the sound, I took the car to the muffler place and asked if there was a leak -- they put the car up and checked and there were no leaks.

I took it to my independent mechanic who could not locate the problem. They put a lot of time and parts into the search -- for which they indicate on the invoice that they put 10-15 hours in (I think they put more time in and were embarrassed to put the time down -- they had the car for 2 weeks) and charged only 4 hours -- they had each of their 4 or 5 mechanics give it a try and no one could solve the problem. The invoice details the different things they tried:

"Fluttering noise on medium to hard accelerations--

from start check over replace drive shaft center support and bearing, renew trans and motor mounts. try a flex disc -- reinstall old one. problem still exists -- suspect problem in trans or torque converter."

In the parts list the charged me for 2 seals, center support, bearing, trans mount and 2 engine mounts. They told me that the engine mounts did need replacing and so did the trans mount.

I am about to take it to the dealership and let them give it a try (I'll tell them what it isn't as above and see if they can find what it is) -- but I wanted to see if anyone here has any ideas what it could be.

I have searched the forum and have not found a similar situation.

As always, I would appreciate your input.

DanielG · #2 08-26-2003, 09:58 AM

I had the car at the dealership yesterday. They diagnose that the rear axle needle bearings are worn and that the entire rear axle should be replaced. They said that MB does not allow them to rebuild the axle --MB is concerned that it will not be done correctly (not balanced correctly). Axle is $700-plus, and installation about $850 -- my indie says he can do it for under $1300 (has to buy the parts from MB --so can't discount parts). -- my indie is the guy who couldn't find the problem in two weeks of trying.

What to do???

blackmercedes · #3 08-26-2003, 01:53 PM

Youch! $850 labour? I had the axles on our old 190E 2.6 replaced and it cost $450 for a rebuilt unit (might not be out there for R107, but it seems they would given the number of those cars still driving) and 1.5 hours labour! The labour was $120! Can the SL be that different?

DanielG · #4 08-26-2003, 02:22 PM

I'm sorry -- not axle, but main drive shaft (between transmission and torque converter) I just re-read my note from my phone conversation with the dealership.

The indie will do it for a total of $1287 -- which means about $725 for the part about $50 for tax and $512 for labor -- I have this posted on the SL forum too --- I was told there that someone was able to get rebuilt parts for a lot less -- and advised to check junk yards, etc.

DanielG · #5 10-07-2003, 12:36 PM

well -- drive shaft replaced and fluttering noise persists.

DanielG · #6 11-15-2004, 04:39 PM

Hi -- This post was made in the SL forum and since I posted in both originally, I thought I would post my new question here as well -- any help will be appreciated! Sorry for the duplication:

The noise continues.

Question: Is there an SRS sensor in the differential (there is some sensor there -- I have seen it)? If so, could this be a cause of the fluttering noise in the car -- specifically, the SRS light in the car has been lit since I bought it -- if the SRS system is tied to the differential could a problem with the differential cause the SRS system light to come on; and working the other way, if it is a faulty sensor in the differential could it cause the differential to behave badly because the car thinks that a crash (or other) condition is existing?
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Dan

1986 560SL (52k miles)