W123, 1980 240D Axle half shaft replacement: Wheels or not? - PeachParts Mercedes-Benz Forum

storaasli · #1 10-22-2003, 01:01 AM

I am about to replace a CV half-shaft for the first time in my life. I've read the procedure a few times and think I understand it. One question for those who have done it: Is it really necessary to remove the wheels and calipers? According to this thread: http://www.peachparts.com/shopforum/showthread.php?threadid=53568&highlight=half+axle
it is up to debate. I don't want to damage my car. Oftentimes, when I remove calipers (due to my ineptitude and lack of a proper spacer), I end up letting the pads in. I'd rather not take of the calipers if I wont damage them by changing out the axle.

Also, any tips abouch changing a half-axle not mentioned in Haynes or Chiltons? Thank you.

Paul
Owned my mercedes for about two weeks!
1980 240D 192k mi

Rick Miley · #2 10-22-2003, 12:46 PM

Wheels must definitely be removed. Calipers, propably not. I was able to get mine done without taking the calipers off but, as always, your mileage may vary. I had trouble getting the new shafts to seat, which I had never seen anyone else post before. The story is here.

storaasli · #3 10-27-2003, 12:57 PM

Is there a differential cover gasket? SHould it be replaced if you're taking the cover off? Sorry. I am an amateur at working on cars!

Paul

Rick Miley · #4 10-27-2003, 01:01 PM

No, you need to buy a sealant. I think I used gray RTV.

storaasli · #5 10-29-2003, 04:46 AM

So I tried to replace one half axle shaft, which in theory seemed pretty simple. Heres what happened:

I jacked up the car and removed the wheel on the side I'm working on. I was about to remove the differential drain plugs when I noticed they're socket-heads. Well, I get out my set of hex drivers, but don't have one that fits. I figured I can make a makeshift hex driver with a nut and bolts. I look all around my garage and dont find one that fits. I go to home depot and look for the 14mm hex driver I'd need to get out the drain plugs. They dont have one. I buy some nuts and bolts to make a makeshift hex driver. I drive to pep boys to see if they have a hex driver. Nope. I go home and try out the nut-and-bolt solution. That is, I had a bolt that fits the sockethead. I put two nuts on it, locked together. I put some liquid wrench all over the drain plugs bang them a bit, and wait a while. I try my contraption and I break the bolt! The drain plug didn't budge. I went back to Home Depot and got some grade 8 nuts and bolts and tried again. I couldn't get enough torque on it to budge.

I then decided that I'd just take off the Differential Cover, and fiddle with the drain plug while the cover is off. I jacked up the diff and removed the four bolts holding the rubber bracket. I then attempt the 22mm bolts holding the bracket to the Differential cover. The bottom one wont move. I cant get to the top one because the sway bar is in the way. I put some liquid wrench on it, and it still wont budge.

Okay, I'll just leave the bracket attached to the cover. I start removing the diff cover bolts. I can get to 6 of them, but the top two are impossible to get a socket and a wrench on. So now I have a jacked up car, lots of bolts that wont budge, or are hard to get to, and not much of a plan. Any Ideas?

Specifically....
1) How do I get the drain plugs off? I think I may try another hardware store tomorrow, and get a 14mm wrench with a long arm for more leverage.

2) How do I get the 22mm bolts connecting the Differential Cover to the bracket off? One wont budge. I cant get to the other because the sway bar is in the way.

3) How do I get the top two differential cover bolts off?

4) Are there any other things I should watch for?

Thanks for any help you may be able to provide. I feel like quite the loser right now!

Paul

leathermang · #6 10-29-2003, 07:30 AM

That is the funniest thing I have read in a long time.... because it could describe the Types of things which happen to me all day long week in and week out. Do you think anyone that has not had those types of things go wrong on a regular basis appreciates them when you finally get them worked out ? Not a chance. My solution is to just make damn sure that when I am AT a job like that that each and every thing which needs to be fixed for the NEXT time you are in that area of the car/project gets fixed THIS time. It takes a little longer... but you know what you have when you get through... and you really enjoy the situation and your foresightedness the next time you have to be there dealing with anything.
More leverage is about the only answer to some of these situations.. like a " cheater pipe" put on the end of your tool.
As bad as the situation may be for access.... taking off the cover to deal with a stuck plug is probably a bad idea... because you then have the added chore of HOLDING it... without warping it. Usually better to just up your tools/leverage or whatever while it is bolted to the third member...

Rick Miley · #7 10-29-2003, 08:59 AM

I'm at my desk at work so I don't have a manual or anything in front of me. But here's what I can tell you from memory.

You must get a proper 14mm hex driver. Check again at Poop Boys. I found a set of three drivers there that contained the right one, but they didn't sell a 14mm separately.

When leathermang says "third member" he means differential. It took me a while to figure that one out.

When dealing with things like the differential and manual transmission, you're supposed to remove the fill plug first before you remove the drain plug. The to prevent you getting the fluid out and then having the car immobile and you can't refill the fluid. Umm, the situation you're in now.

I don't remember removing anything as large as 22mm. The swaybar should be flexible enough that you can push it out of the way to access those bolts holding the bracket to the frame. Not easy, but should be possible. Once the bracket is loose and you can drop the differential those top bolts become accessible.

Rick Miley · #8 10-29-2003, 09:02 AM

Yes, there's something else you should watch out for!!

When you do finally get the cover off and come to the point of pulling those retaining clips inside, drape a towel or something over it to keep the thing from flying away. It took me 20 minutes to find one of them.

romansek · #9 10-29-2003, 11:43 AM

In my case for 14mm(.551") hex I bought 9/16"(.562") Allen wrench and file little. Before reinserting retaing clip I attached small wire in the hole of the end of clip to preventing fling away or get inside differential. When clip is in place (20 min. in my case) I pulled wire out.

lrg · #10 10-29-2003, 12:20 PM

If you can't find the hex bits try these guys:

Samstag Sales - Tools

samiam4 · #11 10-29-2003, 01:06 PM

Paul,

Let's answer your questions:

1) How do I get the drain plugs off? I think I may try another hardware store tomorrow, and get a 14mm wrench with a long arm for more leverage.
Well- you can buy a 14mm socket- Grainger?? Or you can order the correct one.

2) How do I get the 22mm bolts connecting the Differential Cover to the bracket off? One wont budge. I cant get to the other because the sway bar is in the way.

Yes, You do not need to take off the transmission mount-unless replacing it. They can be difficult.

3) How do I get the top two differential cover bolts off?

Use a wrench. I've never had a problem. Once loose- you can take it out by hand if you want.

4) Are there any other things I should watch for?

Yes absolutely. Don't loose the clips when removing them. Make sure they are seated when replacing-or you'll destroy the diff.
I forget the drain plug if you're going to just remove the back cover. Need to concentrate on removing the "fill" plug now-before the cover is off. Take a few hard hits with a ball-peen hammer, then you should be able to take them out "al-la the 14mm bolt/nut trick".

Michael

leathermang · #12 10-29-2003, 03:07 PM

Rick , I was just checking to see if you were reading close.....
Third member is easier to spell than daefferentteial.
If no one ever uses " old mechanic speaK'' it will die out as a language...
Just so you don't think I totally made it up :

http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=third+member&btnG=Google+Search

storaasli · #13 11-06-2003, 06:06 PM

So I finished the axle change with another hiccup. First
to address some comments:

I meant "fill plug" when I said drain plug. When I mentioned I was thinking of just not bothering with the plugs, and get oil all overthe place by taking off the cover, I figured I could get oil back in. First, I though I could use a vice to hold the cover, and get more leverage on the fill plug, or I saw there was a small fill spout at the top of the differential. When I put the cover back on, I could somehow siphon the gear oil back in the small fill spout, checking the level with a home-made dipstick. I did not think of the problem of warping the cover.

Because I was using the bolt with two nuts locked together trick, I needed to turn the inner bolt unscrew things. Turning the outer bolt would result in un-locking the nuts. As such, I had to use an open ended wrench. My 14mm combination wrench is small, so thats why I had problems, at first.

When attempting to get off the 22mm mount-to-cover bolt, I was using my 14-in breaker bar. I thought that was enough leverage...Apparently I was wrong.

In attempting to get the top two cover-to-diff bolts off, I hadn't had the diff lowered. One of my jacking points was the giant subframe member that the diff is attached to, so the diff never dropped until I changed my jack point.

In any case this how the rest of it went...

I did finally find a 14mm hex-head socket at Tool City. I had to call about 20 Hardware and Auto parts stores before I found a place that had one. Coincidently, right after I found the store, my girfriend, out on a 6 mile jog, call me on the cell. She said, "theres a store here called Tool City. Should I ask them about that part you wanted?" I was pretty shocked and happy. I thought I'd have to chase down a snapon truck.

So with the hex head socket, I went to work again. I did put the cover bolts back in to prevent the warping lethermang warned about. At first, I put 18" of pipe over my breaker bar and couldnt get the plugs to budge from under the car. I did hold back a bit, becasue I was under the car, and I didn't like the idea of using so much torque. I then switched to a 36" pipe on the end of my 14" breaker bar. I stood beside the car, and pulled quite a bit. Finally the fill plug bolt moved. The drain plug still required 36" of lever arm, but not as much force.

Once I changed the jacking point as I mentioned above, The top two cover bolts weren't a problem.

The -C clip came out easily with a coat hanger.

I used a small pipe to tap the axle out of the hub, and removed the axle. I now see why removing the caliper is a good idea. It gives the axle a place to go while removing it from the differential. Without removing it, I had to "thread" the axle between the caliper and a brake hose. Had I dropped the axle when getting it out of the diff, I would have stressed the caliper hose.

I put in the new axle, threading between the caliper and hose again. I used a screwdriver to coerce the hub site of the shaft to get into position in the center of the hub. Here I had the problem Rick encountered...

I couldn't get the axle to slide into the hub. I lined up the diff and the hub, and got the axle in a couple millimeters. It would go no farther. I used a hammer on a piece of rubber (an old exhaust hanger I replaced while under the car) to attempt to tap it into the hub. this did not work. Thinking I was smart, I came up with a solution like Rick did. I purchased a 8mmx1.25 x 210mm bolt, and a 170mm bolt. These are just like the axle bolt, except longer. I put some 3/8" nuts on the unthreaded portion of one of these bolts as a spacer, and threaded it into the axle from the wheel side of the hub. With this setup, I could pull the axle in. It worked for several turns. I then switched to the real axle bolt, but it wouldn't reach the axle...still more pulling to do. So I put the longer bolt in and brought it in a little more then...clink...THE BOLT BROKE OFF INSIDE THE AXLE!!!!

Thats the second time I've broken a bolt in this operation, and I don't even have strong forearms! This time it broke because I bottomed out the bolt. I took out the axle and had a friend remove it for me. I don't trust myself to drill out straight and in the center of the bolt. Since I bottomed out the bolt, he figured he didn't have to torque it much to get it out. He used an EZ-out, which worked for about half the bolt, then it broke. He levered out the broken EZ-out and just tapped the rest.

After this, I put the axle back in (very easy since I now have experience) To pull the axle flush with the hub, I used a similar procedure with some minor variations. First, I threaded my longer bolt firt and counted how many turns before the bolt bottoms out. Then I threaded the axle and got it kinda tight without pulling the axle in. I unjacked the suspension, and jacked up the diff. I reversed that, and the axle came in quite a bit. I tighened down the axle bolt some more nd it slid very easily from there. I put in the real axle bolt, and buttoned everything up.

The rear end of the car is running well now.

Thanks for your help.

Paul

samiam4 · #14 11-06-2003, 07:14 PM

Wow paul,

That's an amazing story!! I've been through the ringer on these many many times. I was so proficent at it-when turning wrenchs they came to me.

Let's see. I'll say it again- you can beat on the fill plug. The washer under the steel plug is aluminum. Look up the coefficent of static friction for alumium, figure out the tension applied using the factory torque... you'll see you have to overcome lots of force. It's a good thing ... it will not come loose in service. Really, seen lots of wrenchs and they reach for a ball-peen hammer.

Yep- upper bolts would be a bXXXch without lowering the diff a little. No need to remove the 22mm bolts on the subframe rear mount-unless you are replacing it.

You should be able to work the axle in position with a little strength. I'm assuming, you've colapsed the axle completely to squeeze it into place. C-clipped the inside (after replacing the side seal on the diff). Then you need to get the length to increase and fit the wheel hub. YOu can wiggle and pull on the axle and it will move the inner joint. If the splines will touch, I just screw the bolt in the axle and pull with pliers. Done it and it works. Maybe one-handed and wiggle the axle joint.

Now that you know the routine- *next* time it will be easier.

Michael

GottaDiesel · #15 11-06-2003, 07:43 PM

Seeing how you never did one before and your car is now back on the road, I'd say you deserve a big 'ole slap on the back!

:p