I've been advised by a very good (but top dollar) MB shop to replace my 300E's rear control arms, rear differential mounts, and tie rods.

Are those basically just nuts-and-bolts jobs that a half-decent (and much cheaper) garage should be able to get done for me w/no problem, even if they don't have experience doing that work on MB's?

The difference in price could be substantial, but I only want to pay to have it done Once.

The first shop I definitely go with when something requires extra precision or particular Benz knowledge/experience. Is this one of the jobs that needs the experienced hand, or can I save the money if the cheaper guy is even reasonably competent?

MustMakeAmends,

It should be a fairly straightforward job for a competent shop to replace the suspension arms, but they do have to be aware not the tighten the bolts until the entire weight of the car is on the wheels. If they're tightened in other than the neutral position, the rubber bushings will wear very rapidly. They will also have to realign the wheels when they're finished. The differential mounts (the rear ones, anyway) require a special puller/installer, and a fixture to set the proper distance to the front mount so that everything lines up properly without undue stress. To do it properly, the diff needs to be dropped as the bushings are supposed to be removed in the direction of the front of the car and installed the same way, from back to front. I don't think they could do the job without removing the diff, actually, because there wouldn't be room for any kind to puller with the diff in place.

Here's a link to the Braingears.com site, which has on online version of the MB service CD. You need to download Adobe Reader (I recommend v7.0, it loads much faster than v6.0) and then go to the specific service operation you need:

The main Braingears MB page: http://mb.braingears.com/ . Click on the 124 Chassis disk 1 for engine and electrical (I believe) and disk 2 for just aobut everything else.

Here's a link to the Rear Axle operations . Click on operation 050 for the differential mounts and operations 110, 111, 112 and 113 for replacing the various suspension arms. Be sure to also check out the Technical Modifications and Programmed Repairs for information about updated parts, as there are some with the suspension links and their fastening hardware.

You can print these out and start your own service manual as you go along. I've found it to be a very useful resource.

Hope this helps

Gary

Thanks, Gary.

So it sounds like the rear diff mount job could be the tricky one, and probably best for a shop specifically MB-equipped. I assume that required puller is different than a regular come-a-long?

I suppose I could have the cheaper guy do the control arms (which makes up the the most hours of this work) and tie rods, then let the specialist tackle the diff mts.

Btw, I can download the Rear Axle operations 050, 110, 111, 112 and 113 that you linked to, but could not access too much else on the Braingears site. I'm using a Mac. (I even bought copies of the CDs, which I'm still wrestling with to become totally Mac-friendly)

I don't think this is a "Mac" problem. I just tried to get to the pdf files on the Braingears site (with my Mac) and the message said the page wasn't available on the server. I think the problem is at their end.

MustMakeAmends,

I've attached a picture of the tool used for the diff mount bushings. This is the Sir Tools M 0074.

In regards to the suspension arms, be aware that your original nuts and bolts may be hex head, whereas the newer replacement bolts will will have an 8 or 10mm internal spline (triple-square or XZN) 12-point heads. It is not a Torx head. Make sure your mechanic has this tool. Also, make sure that the newer arms utilize the same diameter bolts that are on your car now. There may have been a change to larger bolts in which case you would need some sleeves to take up the slack because your car would still need to use the smaller diameter bolts in the frame and wheel carrier. Check with the parts person where you're buying the parts. There should be a note in their electronic parts catalog as to whether your year car will need any additional parts when you buy the particular suspension arm.

If you can display and print the pages that I linked, I don't see any reason that you couldn't access any page on that site. If you start at http://mb.braingears.com/ (note: no "www") and select either disk 1 or 2 in the model selection list under the Model 124 Chassis (1986 - 1995) heading what happens? It should take you to http://mb.braingears.com/124_DISC2/Program/matrix.htm . It will display a black page for a few seconds, but then should display the year/model selector matrix where you can choose your car. This will then take you to a confirmation page and then to the main index page.

There's nothing platform specific about any of this as far as I can tell. It's just another web page written in HTML.

Try these links individually and see if you can access the pages:

Braingears chassis and disk selector page - http://mb.braingears.com/ . Choose W124 - Disk 2.

Year/Model matrix for Disk 2 - http://mb.braingears.com/124_DISC2/Program/matrix.htm
Select 88 300E and then confirm. This will take you to the main
index. It should still be on the same url shown above.

Chassis Subindex - http://mb.braingears.com/124_DISC2/Program/chassis_menu.htm - This should display the list of Main Systems on the car, i.e. Central Locking System, Electrical System, Brakes, etc. Choose "Rear Axle - Center Assembly" This should take you to:

The "Rear Axle - Center Assembly" main function Group - http://mb.braingears.com/124_DISC2/Program/rearaxle_centerassembly.htm . Click on "35 Rear Axle - center assembly" and this should bring up the Sub-function group listing, again still under the above url. Clicking on any slelction within the sub-function group should then launch Adobe Reader and display the actual service manual page.

Hope this helps,

Gary

PS - While I was typing this I had no problem accessing any of the pages at Braingear, including the .pdf files. You may have encountered a transient problem with the site.

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The work is rather simple by technician standards. The real problem will be aquiring the proper parts though a general shop. If they wind up at NAPA who knows what you will have. The right parts will be modified for improved performance and require added pieces to make them work.

After its all done a competent alignment tech is beneficial, and they are found where ever you find them: dealers, independents, tire stores. About one in ten that would claim to be, are. If you are lucky.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks for all the info Gary, and Steve. And you've anticipated my follow-up Q: Have any recommended MB discount place to get the parts from? Sounds like that's half the battle... I assume I should stick w/OEM as much as possible, should this also extend to the tie rods, or is that not really necessary?

As for the Braingears site, it's great when I can get it to work, but often after navigating to the particular document group I'm interested in, I'll click on one after another and only get the "not available on this server" message, instead of it initiating the pdf download. I'm browsing in Safari.

MustMakeAmends;
I use a Mac and also have the same problem that you do displaying those pages . When I find the specific page I need and click on that link I get the same message you do. I found a reference recently that said the pages will display with "Internet Explorer". I use "Safari" and that browser is known to not work on some websites. I long ago discarded "Explorer" because of the bugs and holes but may re-install it to try displaying the manual pages.
OliverB