300TD Rear CV Axle Questions - PeachParts Mercedes-Benz Forum

chetwesley · #1 03-26-2007, 02:00 AM

Hi,
I have a 1981 300TD, which I have owned since about Sept 06

Shortly after I purchased it, it started making a clunking in the rear, which would come and go, and which gradually got worse over time until it was constantly happening...

For those who might search this later, it was a clicking/clunking which happened with the speed of the car, and which seemed to be louder when accelerating, and which would then turn to a grinding noise as I would slow down.

It turned out to be a bad driver's side rear CV axle. My dad helped me replace it, and he suggested we replace the other one while we were at it. I wish I would have read some posts about it on this board first, and not bought the cheap Cardone ones... Also, in hindsight, I wish we would have kept the "good" passenger side one.

Now, less than 6 months later, the clunking has returned, though it seems to be coming from the other side now. I got under there and took a look, and it seems there is a problem with not just one, but both of these axles, but I wanted to ask a couple questions, since I am somewhat new to car repair and how all the parts should work.

The driver's side one seems to be leaking grease from the seam around the "can" (sorry, don't know what it is called -- the metal canister part right next to the rubber boot). There is a thick dark grease on the "can" and on parts above it on the underbody of the car (which to me shows that the grease has been "whipping" out of the can as I drive). I think I can assume this means it will need to be replaced sooner or later, right?

The other one looks clean on the outside -- however, I noticed that if I grab the "can" and turn it, that the can will turn indipendently from the axle itself about 1/8 or 1/4 of a turn. It does this both on the wheel side and the differential side of the axle, but does not do it on the driver's side axle at all. I assume this is actually the cause of the clunking. The can should not turn independently from the axle, right?

So, I can get a free replacement for them, since Cardone has a lifetime warantee, but is it worth it? Am I going to be replacing these again in another 6 months? I'd like to take advantage of my free replacement (and don't really have money to buy the "good ones" (or even another set of cheap ones at the moment)), but maybe it just isn't worth it to spend the time to replace them again before the year is up.

Thanks for any tips.

-Chet

Magoo · #2 03-26-2007, 01:39 PM

I guess what the time spent to replace them is worth is up to you. Personaly I would get the warranty ones and replace them at least once, maybe you'll get lucky with the second pair.
Another option is to get a set from a pick and pull yard that are still tight, and replace the boots yourself. There are kits available from fastlane and dieselgiant.
I also remember reading a post not too long ago about a rebuild outfit in Denver. Do a search on this forum.

Eric Eliel · #3 03-26-2007, 01:46 PM

Another victim of the cheap "rebuilt axle" industry.

Denver firm is CVJ Axles. Replace your axles in pairs. Unless you have good access to a shop lift and don't mind doing the same job twice.

And no the lubricant should NOT be leaking out the side of the cans. It should be a heavy oil, not a grease. If its grease, the rebuilder is an idiot and doesn't know what they are doing for MB axles. MB axles came from the factory with a heavy oil, not grease. When the axle spins, it will throw the grease to the outside of the can and most likely stay there. Oil will splash around, so-to-say.

DieselBone · #4 03-26-2007, 03:14 PM

After doing the same job on a TD about 3 months ago I would spend the extra cash and get the "good" ones. I got mine from the Denver outfit and the quality is outstanding. Since you have the axes out I would replace both side seals, and if the front is leaking do it too.

Eric Eliel · #5 03-26-2007, 05:47 PM

The side seals of which Randy speaks, fit into each side of the differential BEFORE the axles are re-installed. These seals are pretty robust and GENERALLY don't need replacing. In order to replace them, you'll need a seal puller and some brute strength. I hear they are not that easy to remove, especially on your back in the middle of the garage.

I've never replaced them, but the list members who have, claim its kind of tough.

The leaks are most likely from the poor quality cans, seals and technique that was used to "rebuild" the axles. Not from differential gear oil.

There are some spacers that fit onto the ends of the axles before they go into the diff. Make sure you pull the old ones out and put them on the rebuilt axles. They look like thin washers. Easy step to overlook.

DeliveryValve · #6 03-26-2007, 09:37 PM

Quote:

Originally Posted by Eric Eliel

The side seals of which Randy speaks, fit into each side of the differential BEFORE the axles are re-installed. These seals are pretty robust and GENERALLY don't need replacing. In order to replace them, you'll need a seal puller and some brute strength. I hear they are not that easy to remove, especially on your back in the middle of the garage.

I've never replaced them, but the list members who have, claim its kind of tough.
......

This type of crow bar makes it very easy to remove the seals.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=7929

nscarr · #7 04-24-2009, 12:31 PM

i've got the other version of differential side seal--i went ahead and started removing the old one and found it stuck to the metal bearing.

with this style of side seal (see pic) does the bearing need to come out?

would the seal puller (pic #2) work?

the lip of the new seal is way too big to just squeeze in there, i think.

any help greatly appreciated!
thanks,
-noah

nscarr · #8 04-24-2009, 09:17 PM

Photo of where I'm at now. Does the metal bushing come out, and how?

Thanks a lot!
-noah

nscarr · #9 04-27-2009, 04:57 PM

I found my problem--besides being a bit dim--I had indeed ordered the wrong seal. The proper seal has a metal backing, while the seal I ordered was entirely made of rubber.

In an effort to remove the existing seal, I actually scraped all of the rubber off the metal backing, which I called "bushing" in a previous post. (Now I know why the scraping was a pita.)

Phil warned me I might be getting the wrong seal. Luckily the local parts guy had one of the proper ones left (just one, tho), so I finally got it together.

Pics for future reference.
#1: differential seal pried off with pry bar
#2: differential with seal off
#3: differential sides of seals (left to right: old, proper, wrong)
#4: axle sides of seals
#5: proper seal installed

Diesel911 · #10 04-27-2009, 06:33 PM

I have 2 Cardone Axles on my Car that have been on for over 1 year now with no problems.
I think it is worth it to return the leaking on for the Warranty.

However, the Cardone Master Cylinder I installed only lasted 1 1/2 years. I replaced it with a New Master Cylinder.
However, it took me a month to find the paper work (I bought it on the internet and picked it up at Kragens Autoparts) I returned the defective one under the warrenty anyway and now have an extra rebuilt one.