82 300CD Front End Rebuild and W126 Big Brake Upgrade - Parts Critique - PeachParts Mercedes-Benz Forum

JHZR2 · #1 12-01-2015, 09:56 AM

Im getting ready to start ordering parts for my 82 300CD.

I will be putting 15" bundts on it, so I should have space for the 86+ W126 "big brake" (300mm?) upgrade.

My intent is also to install the w126 LCA bushings...

I personally just like the look of the bendix calipers that are on my CD, so it is sort of my intent to buy rebuilt Bendix if I can...

So, the list is below, can you critique it? I dont have all the little nuts and bolts...

These are the calipers I believe...

Not sure which rebuilder to get from... Most places, PP included, seem to only stock ATE... But Id like the Bendix ones FWIW...

My front spring pads have four nibs, but PP doesnt seem to offer any front spring pads. May go to the MB Classic Center instead, will have to see...

Any thoughts or recommendations???

Thanks!

ffgb · #2 12-01-2015, 11:53 AM

I have the Centric Posi-quiet semi loaded calipers, the bendex ones. Centric puts a zinc like finish on the calipers which is good because my calipers still do no have any sort of surface rust on them and it has been a year. Just make sure you get the new calipers for a w126 and not a w123, because they are different. The stock brake
pads that come on loaded calipers suck for braking performance. They dust very little but I was going for more bite so I went with the yellow box textar brake pads. They dust a lot bite but have better bite cold and hot.

Also, I see on your parts list you don't have brake lines. You can use your existing ones but you should replace them if they are original and also because you are replacing everything else.

leathermang · #3 12-01-2015, 12:09 PM

Is this going to affect your speedometer reading accuracy ?

jabstick420 · #4 12-01-2015, 03:08 PM

You're missing the control arm stabilizer bushing. With the spring out its the perfect time to replace.

You may want to consider having a spare eccentric bolt. One of mine wouldn't budge and I ended up cutting it off.

How are your shocks? Tie rods, steering shock and idler arm bushing?

Torsion bar bushings?

Lastly, you may want to have a dial gauge to set the play in your bearings.

Monster job, but it's worth the effort!

JHZR2 · #5 12-01-2015, 03:33 PM

Quote:

Originally Posted by leathermang

Is this going to affect your speedometer reading accuracy ?

195/65-15 vs 195/70-14 isn't that far off. Only 0.9%. I suspect there's more error in the speedo than that, as-is.

Pirublues · #6 12-01-2015, 03:41 PM

Will this work for 560SEC calipers? I have a set laying around.

JHZR2 · #7 12-01-2015, 04:33 PM

I'd do a part number here or at the Rock to see if they're the same.

JHZR2 · #8 12-01-2015, 04:41 PM

Quote:

Originally Posted by jabstick420

You're missing the control arm stabilizer bushing. With the spring out its the perfect time to replace.

You may want to consider having a spare eccentric bolt. One of mine wouldn't budge and I ended up cutting it off.

How are your shocks? Tie rods, steering shock and idler arm bushing?

Torsion bar bushings?

Lastly, you may want to have a dial gauge to set the play in your bearings.

Monster job, but it's worth the effort!

Good questions. I did the bilsteins, idler arm rebuild and all the steering parts a few years back. The car has less than 1k miles since...

W123 Tie/Drag Rods and Idler Arm Rebuild DIY

Control arm stabilizer bushings? I got two different rubber bushings, might those not be listed here???

Torsion bar bushings ? Is that the sway bar to firewall? Somehow I couldn't find those either.

The car was from ca and has never seen salt. No corrosion. So since I'll be doing this really slow on available time, if I need them, I'll get them as needed.

I do have a dual gauge and base someplace. Just need to review the diy, as the last time I did brakes and bearings, on my old 83 300D I didn't have them and used the old tighten then back off procedure.

Thanks!!

Junkman · #9 12-01-2015, 05:02 PM

What about the guide rod mount and the bushing where it connects to the Lower Control Arm?

I also had to replace the bushings in the carrier that holds the guide rod mount. I'm still in process and can't comment on difficulty.

The sway bar bushings were like new on both SDs. I'm glad because they are quite buried especially on the driver's side.

Of course use Lemforder where ever available.

I would get some low dust brake pads and consider changing the wheel bearings if they haven't been done. I think one car has Hawk pads. The other always has dust on the wheels. You'll need new seals in the hub if you remove the wheel bearings.

It is a big job but the car will steer like new especially if you change the PS fluid and filter and adjust the box. .

The most risky part is removing the spring. The aftermarket spring compressors suffice. It will help to lube the screw. I wimped out and had the indy install the lower ball joints because he has the fancy MB tool. I knocked them out with a BFH and cleaned the steering knuckle which saved a few dollars.

Consider buying the calipers locally. I've had to return some under warranty and paying for return shipping negates any good deal you get online.

JHZR2 · #10 12-01-2015, 05:12 PM

The guide rod mount is in the parts list. I get a bit of a crunchy sound on slow roll over speed bumps, which I'm guessing is guide rod mount or swaybar bush. Comes from behind glovebox.

Also want to prevent this tire wear:

This car and my old 83 do this. My 81 and old 85 don't/didn't.

cooljjay · #11 12-01-2015, 06:46 PM

Look at the sway/torsion bar mounts on the firewall, if you see any gaps or cracking they need to be changed. As they can cause inner tire wear, since you doing everything to prevent outer tire wear, better do that too...

Also make sure to pay attention to the FSM, when it talks about torquing all the bolts for the sway/torsion bar and UCA after the weight of the car is put back on the tires. They must be tightened in the neutral position...

If the break lines weren't replaced recently I would also add that..

JHZR2 · #12 12-01-2015, 07:38 PM

I did brake lines a few years ago. Have some good pics of how bad they were on here someplace...

DeliveryValve · #13 12-01-2015, 07:50 PM

Don't forget you will need to get the correct sized backing plate for the wider diameter brake rotors.

.

JHZR2 · #14 12-01-2015, 08:32 PM

Good point, thanks! Wonder if these can be had new? Are there differences between models, especially with ABS?

jabstick420 · #15 12-01-2015, 09:52 PM

not sure on this but you may need different lug bolts for the wheels…

the guide rod bushings are saucer shaped and available from lemforder.

they are located right under the spring perch where its bolted to the LCA.

guide rod bushing part # 123-330-14-75-M69 from pelican