Dav_Daddy

Hello I've searched high and low on the forum but haven't found anything definitive about my problem yet?

I'll start at the beginning. Around the beginning of December I noticed a whine coming from somewhere in the rear end of my 300E. It only happened when going around 40-50 MPH. I couldn't figure out what it was and it wasn't that bad so I let it be.

On Christmas I picked up my kids and did a lot of freeway driving. When I was almost home still on the freeway my son sitting in the back seat said it smelled like someone was doing a burn out. When I got home I grabbed a flashlight and saw that smoke was coming from the passenger side rear tire. The tire didn't feel hot to the touch but it smoked for well over 5 minutes with the car sitting.

The next day it looked like there might be some uneven tire wear on both rear tires but I'm not 100% sure.

A few days ago I was going to take it & get a 4 wheel alignment. It was making a rather loud squeaking noise so I thought better of it, took it home & called my mechanic friend

I went to back it out of the driveway before he arrived the next day, with the car in reverse idling backward it jerked to a stop almost like the e-brake stuck. I pulled it forward and parked it.

Later that day when he came buy it backed out of the driveway fine. Going down the road I heard that bad squeak again. It sounded almost like a belt was loose.

When we got to the end of my road I turned left, heard 3 loud clangs and the thing didn't want to move. If I gave it some gas I could force it to move but I thought that was probably a bad idea.

I had it towed home and she's up on jack stands now. The rear flex plate looks fine, and with back end up in the air the rear wheels will spin in opposite directions. They won't spin the same way even with the car in neutral.

I'm thinking it's either that passenger CV shaft is bad, or maybe something in the tranny? I intend to drop the driveline tomorrow and see if I can spin that with the car in neutral.

I recently had the tranny serviced, and the diff has oil. I did have it jacked up on the passenger rear end when I did the fuel pump and filter a couple months ago.

Does anyone have any ideas or advice? I would be eternally greatful for any pointers.

optimusprime m1

I would think if the rear wheel was smoking it looks like the rear wheel bearings have siezed up . Only thing that will warm up the disc .Or service brake shoes have broken up inside the disk The service brake uses the disc as it as a drum in the centre that house the brake shoes ...I would start by removing the rear discs on both wheels.It will be like driving with the brake on till it gets red hot.The rear axle wont warm the wheel up ..to this state . But please keep us informed ,as to what you find.

optimusprime m1

Dont drive this till you find the problem ,or it can damage gearbox or engine .Dont use it any more till you have some one check the disc service brake out and rear wheel bearings

optimusprime m1

How did you get on with your car problem?

optimusprime m1

no reply ?

Yura_Coupe

Seems like you have a problem with rear brakes - main or parking.
Check them on the smoking wheel.

Dav_Daddy

Sorry about taking so long to post an update.

It was the differential, once I got it out of the car and opened I could see a lot of wear on the main gear. It would only turn backward so I believe the main bearing the one to the driveline is bad. I found a used diff on EBay (115k mi) for $200 so I snapped it up.

Removing the old diff was a major PITA! This car had been hit in the rear end before I bought it, so one of the bolts mounting the diff to the subframe was slightly bent. I stripped it out trying to remove it and wound up having to use a hacksaw and a MAPP gas torch to get the damn thing off.

Of course that toasted the mount too, (I can post detailed instructions on how to replace differential mounts with Vaseline, sandpaper, and a slide hammer, if you don't have the MB tool.)

The only other snag I hit was with those stupid Star bolts holding the CV axles on. Those damn things must have been cemented in. I tried breaking them loose with my impact wrench, every time the darn things would strip out. I wound up pulling the diff with them still attached. I had to use an angle grinder to take the heads off to remove the CV's. After I removed the CV's I tried to remove the bolts a pair of vice grips and they still wouldn't budge.

I've just about got her back together now, I'll update again after I'm finished.

optimusprime m1

Dave thanks for your reply .You have the problem in hand ,i can see your handy with your hands .Hope all is fine after your ordeal.

Dav_Daddy

Thanks Optimus, I plan to have her back on the road tomorrow. One of the CV axles didn't seem to have the full range of motion so I decided to err on the side of caution and replace it.

I ordered one off of ebay and when I opened the box inside was a wheel hub and brake rotor! I got a refund for that (they let me keep the parts as well so bonus!) and I ordered the correct part off of Amazon with 2 day shipping.

A quick question. I've seen Mobil One 75w-90 synthetic differential oil recommended most frequently. I seem to recall though that synthetic oils don't always agree with these cars? What do you recommend I use in the diff?

optimusprime m1

Dave i dont know, as its a part on the car i have never operated on .But just wait for some other member to reply to,,.. I would stick to mercedes recomended oil types.