W124 Broken Front Spring

[Chris Blanchard]

My 92 300D 2.5 Turbo has been diagnosed with a broken front left spring. I understand that this is quite common for the W124 series. Fortunately, only about 1" or so of the bottom of the spring is gone.

While I wait for my mechanic to give me a quote to replace both of the springs (I'd bet the right one is on it's way too), I'm adding up the cost of doing this job myself.

I'm sure my mechanic will want in the neighborhood of 2 hours plus parts to do both sides. I figure this to be about $350-400.

For somewhat more than that price, I could:

1. Replace the front struts (not leaking, but at 154k it could be time).
2. Replace the ball joints (one is leaking rusty grease).
3. Replace the control arm bushings.
4. Replace the springs.

I figure these parts (plus renting the spring compressor, $75) to be about $600 from online sources. I'll get a machine shop to press in/out the ball joints, assuming they are like the ones on my old w126.

Am I missing any items that should be done?

Thanks!!!

Chris Blanchard
1992 300D 2.5 Turbo 154k

[csnow]

I have not heard of broken springs being a common problem.

Absolutely replace the balljoints and CA bushings. Too much trouble pulling the springs to need to do it again anytime soon, even if bushings are passable.

May want to order up new eccentric bolts. Sometimes they need to be cut off. Could ruin your whole weekend. Dealer does not sell just the bolts. They sell an entire bushing kit with bolts that is brutally expensive.

If you do replace struts, order up accordion boots and bump stops, which are not included. Also consider condition of upper strut mounts. I have found these to be pretty durable first-hand, but a number of folks have reported problems with them wearing out.

I prefer Bilstein HDs.

Special note regarding CA bushings:

If you use a press, you cannot simply press on the face of the bushings. They will not go in regardless of force. They will work against each other. The force must be applied to the metal jacket around the edges. I use 2 iron pipe fittings and a big vise. FSM shows tool with 2 short 'pipes' and a nut and bolt passing through to squeeze bushings together. Also, the flats on the bushings must be oriented in a specific way for front vs. back bushings.

For balljoint, I use a vise, a pipe, and a BFH. Pay attention to the reference mark on the balljoint for proper orientation.

Best of luck.

[Chris Blanchard]

Thanks for the tips.

Spoke with the mechanic, and he tells me $550 for both springs, including an alignment. Ain't happening.

I was thinking about the upper strut mounts too. Hmmm...

As for the eccentric bolt, I was considering that kit as well. The control arm bushing kit is like $50. I assume that you get both bushings in the kit, making the total $100 for both sides.

As for getting the bushings in/out, I was planning on using a homebrew tool that I used to replace my rear trailing arm bushings on my old W126 (a length of threaded rod, and a bunch of strategically sized nuts/washers/etc). That tool worked like a champ...

Thanks for the reminder on the bump stop and bellows...

I prefer Bilstein Comforts, I just want a stock ride.



Chris

[haasman]

Chris

While you are there, so to speak, replace the front and rear sway bar bushings. Inexpensive, easy to do and really makes a difference.

Haasman

[csnow]

Oh, that reminds me.

Bushings can be tough to get out sometimes (Just the first one- second one can be easily knocked out from behind). If chiseling away at the metal edges does not work, you can drill a hole through the face of one bushing, then insert a punch to knock out the other one from behind. In fact, this is perhaps even easier than messing with the chisel in the first place...

Your 'nut & bolt' install technique will work, though the force still must be applied the the metal rings around the edges, as opposed to the metal faces. Hard to explain why without show & tell, but basically, the inner metal tubes on the bushings collide with each other before the outer rings seat on the CA. Put another way, the rubber in between gives before transmitting enough force to the outer rings.

I'm pretty sure my 'special install tool' is a 2 inch female pipe fitting with the first 1/4 or so of threads ground away. After knocking them in part way with a hammer, I put one 'tool' over each bushing, and squeeze them both home at once in a vise.

Without a vise, I could imagine getting threaded male caps for the open ends of my fittings, and drilling a hole in the center of each cap to accept the threaded rod. 2 washers, 2 nuts, some torque, and you are good to go...

Best of luck.

[tvpierce]

FYI,

When I did the control arms on my 201, it was cheaper to buy new control arms (with bushings & ball joints already installed) than it was to buy the parts and have them pressed in. And as an added benefit, I could do it all in one weekend, as apposed to take them out one weekend, take them to the shop for press work on Monday, then install them next weekend.

Just food for thought.

Jeff Pierce

[csnow]

Worth looking into, though at around $220 per CA, I could not make this work. At least with online prices:

Balljoint =<$25 each
Bushings=$50 per side

[J.HIDALGO]

I have the springs from my car in the garage I can let go for cheap. Nothing wrong with them, I just changed them to H&R's. Send me a private e-mail if interested. It is not hard DIY but, you must have the right tools. Be safe!