My car is a 1988 190e 2.3 8v and I have a terrible whine coming out of the differential all the time now. It started around a month ago and I have no ideas on how to address this issue.

Yesterday, I just changed the fluid with Red Line 75 W 90 Synthetic and I know in some of the other posts it was recommended to go to a 75 W 140, but since it gets so cold here, I thought it might not be such a good idea.

Thanks in advance

philipminion:

My 1991 300E has been whining for the last 30kmi or so and I have tried all type of fluids and I think I found one that works for me.

The first one I tried was Mobile 1 synthetic 75W90. It did reduce the noise and I left it on for 20kmi.

Then I came up a tip from a Jag mechanic. He said whine could be due to mis-alignment of gears and slightly work gears. He suggested a heavier oil. I wanted to try this so I went to Wal-Mart and got some 85W140 dino oil and out it in. WOW, what a difference in noise reduction.

I was afraid that the dino 85W140 is too thick for winter so I started looking for a heavy synthetic oil. Redline comes to mind and I contacted them about the situation.

They even have a heavier one called ShockProof Heavy (65W250). They did not recommend me using that but said 80W140 should not be too thick. So I bought a couple qrts and out them in. It does miracles, the noice is very reduced now and I can only hear it between 55 - 60 mph now.

To MB purists, please ignore this post as the 80W140 is a heavier oil than MB recommends (SAE 90). But my 300E is 11 years old and it has some miles now so I am willing to try. Since it is a 80W140 synthetic, the low temp viscosity is not too thick.

you can also try swepco 201 which is non-synthetic. my differential has quieted down considerably since i switched...

__________________
joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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jsmith:

I know some Porsche owners swear by the swepco stuff.

What viscosity did you use?

i got it from this place from one of the threads:

http://www.ritegear.com/SWEPCO/201.htm

80w/90 is all i used, then i gave the leftover oil to a friend with an e420 and he thinks that it made a difference in his car too. weird stuff though, it's blue in color.

__________________
joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif

I did a 300e that had a whine in the rear end . It had a bad pinion bearing , replaced the pinion bearings and all was fine again .

Jim:

Did you have the pinion bearings replaced at a MB dealer or independent?

I heard the bearings are difficult to adjust so it is recommended to buy a used unit and replace.

Do you, by any chance, remember the cost to replace the bearing?

Thanks.

I replaced the bearings myself . The bearings weren't very expensive . You also need to replace the crush sleeve that sits between the bearings . There is no adjustment it just needs to be torqued to the proper specification . I did not replace the carrier bearings . I did do a pattern check before and after just as a check and it was the same .

I'm really starting to get quite annoyed with my differential since it won't shut up for one second. I hear that horrible whine the whole time the car is moving and I think it may be time to fix this problem.

Would you be able to give me a brief description as to how you went about fixing yours and how much $$ it cost you. I've never seen the inside of one of these and have no idea how complicated it may be.

I'm just trying to calculate the amount of time and amount of $$ that may be involved, so that I can see which route I will take.

Thanks in advance.

A differential is a bad place to learn how to fix cars. If you have a constant whine that is unchanged with load then you probably have bad carrier bearings. It the noise changes when you let off the gas it is probably pinion bearings.

Pinion bearings are NOT just tightened to a torque. They are tightened till the crucsh sleeve is crushed to such an extent that the bearings are tight enough that is takes 10-15 inlbs to turn the pinion. The only torque involved is the rotaional torque necessary to turn the bearings which are not now freewheeling. Very critical adjustment. This also must be done without the carrier present as the load of turning can only be the bearing supported pinion shaft.

The carrier bearings are shimmed to get their preload and are then checked the same way (force to turn). Once these perpendicular axises are established both the distance into the ring by the pinion (pinion depth) and backlash must be measured and adjusted possibly redoing both previous settings.

Usually one can replace the bearings without massive shim changes on the pinion. Its almost impossible to change carrier bearings without reshimming.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

A costant whine can also be a wheel bearing or the drive shaft center bearing.
Both can be easily detected on a lift with a stethoscope.
Most diff whines are more pronounced under load.
Just something to check.

Thank you for the info. I'm going to think about it a little longer and post what I do and my results.

I think I'll put the car on the lift and check it with a stethoscope like you suggested on Monday and see if I can find something .

I just changed my rear wheel bearings about a month ago and what a job that was !

I also changed the driveshaft center support bearing and the flex discs that same day, and I change the differential fluid every 12,000 miles/20,000 km.

philipminion

The first thing I would do is drain the oil and check the magnetic drain plugs for metal shavings , if they are present then you know a bearing is bad . The procedure to replace the bearings was to remove the differential center section from the car . With the diff on a sturdy work bench remove the rear cover inside you will find large c clips that hold in the stub axles , before you remove them place a locking tool or a rag in the gear and remove the nut for the pinion flange then remove the c clips . You will need to get the center section out of the housing they are a tight fit ( I used 2 large prybars factory tool is a spreader setup ) . Take very close inspection to the side to side adjustments of the carrier bearing adjustment shims and do not change them .I also used some gear marking compound it is painted onto a section of the ring gear and you spin it thru the pinion gear and you can see the pattern of the gears meshing . Once the center section is out you can check the condition of the carrier bearings mine were ok . Remove the pinion from the housing and press off the bearing from the pinion ( you may need to tap the pinion out of the front bearing not a problem if being replaced . Tap out the bearing races from the housing and replace with new ones . Press on the new rear pinion bearing replace crush sleeve and reinstall shims . Install into the housing and install front bearing and pinion flange . When torquing pinion nut do it in several increments and spin the pinion to be sure it does not lock up . When done the pinion will turn stiffer than when it was taken out from the new bearings not being worn this is normal . then I rechecked the pattern on the gears to see if it was still the same . I hope this helps you to make a choice as to do the job yourself I would have a repair manual for reference . I have done differential repairs before just not on Mercedes . I cannot afford to have a shop work on my cars so I do everything myself that I can . I also work on Italian cars for a living ( no Fiats ) .

Thank you very much for that wonderfully detailed message. I'm not sure what I'm going to do yet, because I've run into another problem that I feel I must deal with first. One of my pistons rings may be broken and so I need to address that issue first.

I do have your post and when the time comes I'm syre it will be a great help.

Thanks again.