I just installed my junkyard Axle and I have questions... - PeachParts Mercedes-Benz Forum

i-osprey · #1 10-03-2009, 04:38 AM

My driver side axle had a torn boot and it has been torn for quite some time.

I was getting some binding noises when I started moving forward and when I really got on it.

So, I decided to replace the axle on that side.

I looked at parts online and the only one recommended for that year, '93 W124 300D, was $380 or so.

I later found, after I bought a junk yard one for $100 plus shipping, that you can actually use a shaft from an older model on the newer rear end but you can't use a new shaft on an older rear end.

NONE of the parts searches online stated or showed this so I felt I needed to try my luck at a bone yard.

The axle arrived and the boots looked good but I noticed that the clamp looked like it had been hammered on and there was a bit of grease coming out of the end of the shaft.

I installed the axle and I HAVE THE SAME NOISES coming out from my rear end.

So, either I got a bad axle that somebody at some point replaced a torn boot on or my rear end is bad.

I will say that I noticed that I have some oil dripping out of the front of my rear end.

It looks like it is coming from the seal around the input shaft, if that's what it's really called, that bolts on to the rear flex disc.

What are the odds that I got another bad axle and my rear end is fine?

The sound is most obvious from a dead stop but it continues if I accelerate hard.

I don't seem to hear any noises when going down the highway but occasionally I get the impression that there might be some shuddering but it could just be road surface condition.

What does a rear end sound like when it goes bad?

What other symptoms should you experience?

What are typical symptoms of a bad axle/cv joint on a rear drive car?

gradyg3 · #2 10-03-2009, 01:23 PM

rear axle going bad can make big clunking sounds or steady clicking sounds when you are going into a turn or slow turn, especially at low speeds. if you have a drip at the forn of your diff believe that is the pinion seal, no big deal if it is a slow leak, just make sure you check the gear oil level in you diff regularly. Not sure about diff in the W124 but know the W123 diff is pretty tractor like and indestructable other than maybe seals needing replacement, but even that is rare fom what I have heard and observed from the W123s I ave owned (still have one). Also check bearing play on the rear wheel where sound is coming from as that could also be the culprit. Good luck.

pmari · #3 10-03-2009, 02:16 PM

My W124 rear end would howl between 20 and 40mph and the intensity would change with speed. I too had the seal leak(weep) at the flange. I first tried running amsoil synth rear end fluid. It made it quite down but not disappear. It eventually got louder and occurred at a greater range of speeds.
Finally changed it out. I looked for a LSD but couldn't find one cheap enough.

http://www.w124performance.com/docs/mb/other/differentials.pdf

If your getting a metallic clicking/grinding (binding?) check your emergency brake pads and hub.

i-osprey · #4 10-03-2009, 05:32 PM

It only makes this noise from a stop.

As I accelerate, there is a noise that I can only describe as "binding."

It's not metallic per se but I don't know how else to describe it.

It also will occasionally make this noise at other speeds if I accelerate hard enough.

There's nothing that sounds like bad wheel bearings and the hub looked fine when I replaced the axle.

I am also getting some of the best fuel mileage I've ever had in this car.

I am at 29-31 the last two tanks and before I was struggling to get 27.

Lately I have done a diesel purge, changed oil from Rotella Synthetic to Mobil 1 Truck and SUV 5W-40 and replaced transmission fluid to Valvoline High Mileage Dexron/Mercon.

I have also not had to run my A/C during this time but even before the summer I wouldn't ever get this kind of mileage.

If it's the emergency brake pads binding wouldn't I be able to tell?

I don't think that's it because I used the E-brake to hold the axle while I tightened the axle flange bolts and it held when it was supposed to. It also let go when it was supposed to.

I don't know how to describe this noise except that maybe it's like driving over those vibration strips they put on the shoulder of the road nowadays for a second or two and then it stops as acceleration lets up.

I am pretty sure that the axle i replaced was bad because now I don't get the clunk/thunk I got before when shifting from reverse to drive as I back out of my driveway.

I just think there's something else wrong but I have no clue what it is.

i-osprey · #5 10-03-2009, 05:36 PM

Quote:

Originally Posted by pmari

My W124 rear end would howl between 20 and 40mph and the intensity would change with speed. I too had the seal leak(weep) at the flange. I first tried running amsoil synth rear end fluid. It made it quite down but not disappear. It eventually got louder and occurred at a greater range of speeds.
Finally changed it out. I looked for a LSD but couldn't find one cheap enough.

http://www.w124performance.com/docs/mb/other/differentials.pdf

If your getting a metallic clicking/grinding (binding?) check your emergency brake pads and hub.

What's a LSD?

aaa · #6 10-03-2009, 06:02 PM

Limited Slip Differential

i-osprey · #7 10-03-2009, 06:09 PM

Does a 300D have a limited slip differential?

sixto · #8 10-03-2009, 06:12 PM

ASD was an option. You'll know by the warning light in place of the 120 km/h tickmark on the speedo, a hydraulic pump behind the power steering pump and a hydraulic fluid reservoir in the engine bay.

Sixto
87 300D

pmari · #9 10-03-2009, 08:39 PM

Quote:

it's like driving over those vibration strips they put on the shoulder of the road nowadays for a second or two and then it stops as acceleration lets up.

Yes it's a vibrational sound that reverberates in the cabin. Sometimes it changes pitch or intensity with different speeds or driving situations, like accelerating and decelerating. Unlike bearing howels that come and go during cornering, when it's loaded and unloaded. Have you changed the rear end oil? If not it's worth a try to see if it makes any difference. Plus with a leak at the flange(pinion) seal you may just be low on oil......but with high mileage cars it's not likely going to be that easy

i-osprey · #10 10-03-2009, 09:51 PM

I changed the diff fluid about 10K miles ago.

I didn't see any metal in the fluid but I only really got a close look at the oil that was left on the top of the drain pan after the rest had drained into the pan.

I also wanted to add that when I hold the brakes and give it some accelerator it will make the same kind of crunching/binding sound that it does under acceleration.

It was shifting very harshly when I first got the car because of a serious vacuum leak in the bird's nest.

It was like this for about 10K miles after I got it and untold miles with the previous owner.

Based on that and what I read about another poster's W123 I suspect that I have some damage in the diff.

I don't have the ASD.

There's no pump behind the steering pump or a warning light.

pmari · #11 10-03-2009, 10:55 PM

Quote:

Originally Posted by i-osprey

I also wanted to add that when I hold the brakes and give it some accelerator it will make the same kind of crunching/binding sound that it does under acceleration.

That's not good! Is the drive shaft spinning when your hearing these sounds? How are your flex disks?

With the car in neutral try turning the drive shaft at the rear diff see how much play there is. You can also try jacking up the rear wheels with the car in neutral and try turning the shaft and spining the wheels. It should be smooth with little play and no lag or skips.

i-osprey · #12 10-03-2009, 11:51 PM

Quote:

Originally Posted by pmari

That's not good! Is the drive shaft spinning when your hearing these sounds? How are your flex disks?

With the car in neutral try turning the drive shaft at the rear diff see how much play there is. You can also try jacking up the rear wheels with the car in neutral and try turning the shaft and spining the wheels. It should be smooth with little play and no lag or skips.

The flex discs look new.

I will test the play in a few minutes.

i-osprey · #13 10-04-2009, 02:03 AM

I drove the car up onto ramps, put the tranny in neutral and killed the engine.

I then proceeded to try to turn the drive shaft back and forth.

It moved and even did so with some metallic "pinging."

I could move it back and forth maybe 20-25degrees(very rough estimate).

The axle flanges were slightly moving as well.

Is this a sign of excess wear?

pmari · #14 10-04-2009, 02:26 AM

Hard to tell from this side of the key board, I was told there should be less than a 1/2" of shaft slop before she engages drive shafts.If you have it on jack stands(rather than ramps) and let the wheels turn (in neutral) you'll get a better feel for the slop.
Hopefully one of the guru's chime in with their .02$

tobybul · #15 10-04-2009, 08:41 AM

Glad you mentioned amsoil syn. I also put amsoil syn a few months ago and noted that the howling is at a greater range. I tried it thinking that it would make the noise go away but I think it got a bit louder.

I have also noticed vibration at high speed that never happened b4. I now plan to go back to Mobil 1 or just put dyno oil in the diff.