Wierd banging, clank, rear end.... on the 81 300D
 

Got this odd issue that comes and goes.. Sometimes the car is fine, drives fine etc, other times you get this loud banging clunking, like a chunk chunk chuck from the rear end. I thought it was due to bad brakes, but I had them all replaced yesterday and it started up again today... I don't SEE anything but it's defiantly coming from the rear wheels someplace. Sometimes it's loud, sounds like someones banging the back end with a hammer, and you can feel it in the car... other times it's soft... or gone...

Coming home just now from another test drive it was fine, then I make a sharp left turn and bang bang bang...

Driving me nuts.

LOL,
try backing up when that happens...
not far.. 20 feet would cure it for hundreds of miles in my wagon..
it is 98 percent the half shafts....

Adding a little heavy oil to the cv joints if the boots look good may fix you up. Depends if they are partially dry now and the amount of wear present if much.

If you have a bad axle, one of the mods actually rebuilds them.

Going to run it into the shop this morning and have the rear wheels pulled back off and take a good look, see what the issue is and order the parts.

heh, I don't rebuild bad ones, I only Reboot Good ones that have cracking but not broken boots.
it could also be the rear swaybar links. they get REALLY noisy on occasion when turning or backing up...

x1 on sway bar links....easy to check and easier to replace.

Make that x2. They can make all kinds of racket.

x3, I thought my shocks were going out when I first bought my car but it turned out to be the links.

I would not let that garage put in a chinese replacement axle if they want to. They are cheap but there are potential problems. Good used axle is superior usually in my opinion.

Unless the garage has a lot of experience with this brand they will not Know that adding a little heavy oil to the cv joint can be helpfull. Unless you have an exceptional example running for paid service is going to require deep pockets.

The beauty of these cars is you can maintain them yourself unlike many modern cars. If a person cannot or is unwilling to tackle most things they may not be the car to own.

I know I would not recommend one to a friend if either he did not mind throwing a lot of money at it or was prepared to deal with any faults himself.

These are older cars with lots of miles on them usually and have not been well kept up by previous owners. There are exceptions of course but they are not the general run of used cars of this type available.

Then again as suggested it may only be the sway bar links as some have mentioned. From your description I would not count on it.

It's the axel. I took it over to the shop I use this morning and we put it back up on the lift and gave it a good looking at. The axels banging right where it meets the pumpkin. there was a dime size hole in the boot protecting it.

We took a grease gun and filled it up with grease. Cost... free.

Drove it about 100 miles today with no further problems. Plan on getting a new axel for it in a week or so.

You will have to eventually replace the entire axle.

It isn't hard, just time consuming if it is your first DIY. The show can do it easily as well.

CVJ axle's mailed me rebuilt axles that I have on right now. They're doing very well.

The oil however will spill out quickly, wrap the entire joint in duct tape and you can drive for a few thousand miles before replacing them :cool:

Thank You.
I love it when everyone else lines up on the other side of my advice... ( Sway bar Links --HA !!! ) LOL

However, you likely have not fixed your problem...
First , as I mentioned.. mine would quit the noise for hundreds of miles at a time for little or no reason.. but almost always if I stopped and backup up...

Second, The Factory Installs Heavy OIL... not grease... as you can imagine if you think of the physics.. as soon as you get that thing turning fast centrifugal force will throw that grease to the boots...and since it is grease INSTEAD of OIL.. it will stay there...
so , you need to fix your boots so you can install OIL.. which will be able to splash on the parts needing lubrication.

Cool. I put in 2 entire grease guns full of grease.... so far so good,

I really wasn't convinced it was sway bar links, usually sway bar link make rattling noises. But they are easy to check, and cheap to replace. So it's a good place to start. You'd mentioned the axles, so we were mentioning something else. Thats the beauty of the forum, is you can get lots of options to check, which I guess can be a bad thing too, but I always figure more info is good.

Barry, I was not being as serious as it looks like you took my kidding...this is not a competition.. the purpose is just as you described.. .to be helpful..... I did not even know the sway bar links could cause a sound like was described.. so it was good that that was mentioned so if it was not the half shafts he would immediately know another logical place to check...That IS the beauty of the forum structure...

There was no intent to contradict from me as well. It could have been sway bar links or stabilzer bar links depending on ones terminoligy.

I never feel that I have any bettter suggesions than anyone else. Personaly I expect his cv joint is still good. All he needs really is the boot changed and some heavy oil injected and he will probably never hear from that cv joint again.

The local parts suppliers like napa all over the continent supply new chinese replacement axles. The Chinese never got their quality control right up to the present time so it is a hit and miss thing. A better choice in my opinion is a used axle from a salvage yard if the boots are intact. Just add a little oil inside the boots and drive on. Or remove both boot clamps and slide back the boot. Clean the joint properly and add the new oil.

New chinese axles are about 100.00 and a used one with good boots about half that usually. Mercedes new originals probably between 4-500 new although I might be slightly high on price.

I really think an individual is better off in cases like his just rebooting and putting that axle back into service. Unless dirt has worked it's way in.

Anyways I never felt any slight or whatever and hope I did not imply one myself. I would never mean to but might unintentionally by some ommision or projection. I also never feel that I am in competition. This site is a form of relaxation therapy for me at least and many others I hope. The last time I really felt I was truly correct about something the wife wasted no time in correcting me.

Many on site members also have more knowledge and experience than myself. As you state the site is all about making suggestions. We do not even get to experience the individuals fault or hear the noise on his car personally.

At this point it does sound like he has found a garage with a reasonable attitude so far at least. This in itself is far from common today.

heh.
I've got good rebooted axles from my stash of cars that did not have open boots. I pull, oil or grease, and reboot them.
I ship anyplace in the us. so far.
I've got 3 sets of 123 axles, and 2 sets of 126 axles left. I may have more, as I've gotten a pair of cars in recently that may have a set in them that are not damaged.

I also have the boot gun available for rent if you would like to clean, and reboot your own, but since it's already clunked, and is likely damaged, I'd not do it myself to your axle. the boots cost about 30.00 per axle, and they come with grease and clamps. but I like to use Mobil1 Gear oil.

Agree totally... no way for it to cure itself... although on the other hand I have heard of people driving tens of thousands of miles with bad cv joints... so it would be a chance if it had the correct lubrication that it would last a long time...
As I said about mine... after they started banging really loud the first time.. and I drove 10 miles home at 15 mph... once the ' backing up ' trick worked.. it would be quiet for several hundred miles...
I don't usually give such ' on the fence' answers... must be the cold weather...

VS, I'll get with you about getting an axel for it in a bit, I want to see how it fairs for a bit first. BTW, how hard a job is it to replace them?

Is there a place with downloadable workshop manuals or whats the best how to book for these 123's? I found all kinds of stuff for the 124 but no luck so far on the 123.