doing front shocks tomorrow - is my technique right? - PeachParts Mercedes-Benz Forum

JHZR2 · #1 02-04-2004, 12:25 AM

Hi,

I am going to install my new bilstein HDs onto my 83 300D tomorrow am. I am excited... Everything has been sprayed down with pblaster so it should go smoothly I hope. I am writing down my technique so that I can verify it... so I dont have problems or have to redo anything.

My plan is as follows:

1) Turn wheel all the way to the side of the car which is having the shock replaced
2) Jack car up, remove wheel
3) Loosen lower bolts with a 12(?) point socket
4) Loosen upper bolt, press shaft down as much as possible
5) remove shock by jimmying it slightly and pulling it downward
6) clean lower bolting area
7) Prepare new shock: for the lower side the order is the bump stop, the protective sleeve, cupped washer with cup upwards, rubber bushing
8) Bolt new shock at lower two points - torque correctly
9) Turn shock shaft so it will rise from the gas pressure. Lead it into the hole in the body.
10) Place rubber bushing then cupped washer face down, tighten nut onto shaft and torque correctly
11) re-torque everything, attach wheel, lower car, repeat for other side.

Does this sound right? I am still a bit hazy about the order that the hardware parts go on... There is the 4" long bump stop that came on the shock, the protective sleeve, and then of course the two rubber bushings and cupped washers.

Any comments on my method would be great. Can I get away with doing this without lifting the car or removing the tire? It almost looks as if I could...

Thanks,

JMH

psfred · #2 02-04-2004, 12:49 AM

I usually remove the top mount nuts and rubber, then remove the nuts (or bolts) from the bottom. A worn out shock will be easy to compress, just lift it up and swing it out, then pull down.

Match up the hardware from the old to new shock -- should be a diagram in the box anyway.

Rears are even easier on those models -- the bolts go in from underneath.

Peter

MS Fowler · #3 02-04-2004, 04:58 AM

My new shocks came with new 6 pt cap screws for the bottom mount. The threads were the same, but the heads were larger--in fact, too large to fit and allow a socket room to go on the head. I had to reuse the original bolts.

Scott98 · #4 02-04-2004, 08:09 AM

After I put new shocks on my '85 I took the car to a mechanic to get other work done to it. He told me I put the cup washers on upside down on the front shocks. He said they were supposed to face up, not down. Don't know which way is correct. That's just what I was told.

Scott

tjohn · #5 02-04-2004, 12:19 PM

Just make sure you don't let the shafts rotate while you torque the new shocks. You need a little wrench to go across the flat part at the base of the shaft to act as a counterhold. I think its a 7 mm wrench IIRC.

HGV · #6 02-04-2004, 12:21 PM

I think an important step is missing. Of course it mught be to late and you will find out the hard way. Hope I am not to late with my concerns.

The shock serves as a suspension stop. It is an active link on the 123 chasis cars as opposed to the 115 chasis which use the conventional double a-arm suspension. You need to support the lower a-arm while you are replacing the shock or the the spring will fully extend and fly out. This is a very bad thing and can ruin you day.

Place a floor jack under the a-arm and pump it until you take up load, then remove he shock bolts and the shock absorber.

Someone tell me if I am wrong on this.

Henry

Eric Eliel · #7 02-04-2004, 12:24 PM

The bolts that hold down the bottom of the front shock is a 12pt 10mm. Its a tight fit and you might need a 12pt. open end if the socket combination you are using doesn't fit. It won't work with a 6pt. 10mm (if the shocks have those special bolts). I don't care for that bolt design.

Scott98 · #8 02-04-2004, 12:27 PM

Quote:

Originally posted by HGV
You need to support the lower a-arm while you are replacing the shock or the the spring will fully extend and fly out. This is a very bad thing and can ruin you day.

I just did all four shocks on my 123 a couple weeks ago. You don't need to worry about the spring. Just put the car up on jackstands and remove the shock.

Scott

Scott98 · #9 02-04-2004, 12:28 PM

By the way, JHZR2, do a search under my name. I posted the general procedure for doing this a few weeks ago after I replaced my shocks. Good luck.

Scott

HGV · #10 02-04-2004, 12:37 PM

Scott, where do you put the jack stands? Under the frame rails or under the a-arm? I know that on the 124 chasis, you need to support the lower a-arm or the spring will come out.

Just curious. Have not owned a 123 chasis but did work on a friends.

Henry

tjohn · #11 02-04-2004, 01:13 PM

Quote:

Originally posted by HGV
I think an important step is missing. Of course it mught be to late and you will find out the hard way. Hope I am not to late with my concerns.

Someone tell me if I am wrong on this.

Henry

You're wrong

What you've described is not an issue for the 123/126 style suspension. I followed the instructions right out of the manual (for my 126), and all that's needed is to jack up the car securely. Good looking out though, better safe than sorry.

Scott98 · #12 02-04-2004, 01:17 PM

Quote:

Originally posted by HGV
Scott, where do you put the jack stands? Under the frame rails or under the a-arm?

I put the jack stands under the frame rails.

Scott

rgp123 · #13 02-04-2004, 02:13 PM

I'm doing front B'stein HD's on my 240D. The black parts book shows no donut bushing on the underside and when I took off the old Boges (originals?) that is how they were installed. The HD's come with plenty of hardware, does it all need to be installed or put it back like the book and Boges were?

JHZR2 · #14 02-04-2004, 02:29 PM

I had a somewhat major problem... Although the shock length seemed to be the same as on the old ones, the new ones stuck much further through the hole. Turned out I had to use both rubber donuts, then the cupped washer, then the locknut.

I cant imagine I did something that wrong to mess it up... But it woprries me a bit, as the old ones had clearance on the right side so the shock post could sit under the AC hose that was going along that way. With the new ones, they touch slightly...

JMH

Scott98 · #15 02-04-2004, 02:38 PM

If they are touching you might want to put a piece of tape around the AC hose so you don't wear a hole in it.

Scott