K-MAC bushings vs. Adjustable camber arms - PeachParts Mercedes-Benz Forum

ksing44 · #1 12-30-2003, 08:40 AM

What is the best way to adjust rear camber on a W124?

Link for K-MAC Bushings:
http://www.k-mac.com.au/

Link for Adjustable Camber Arms:
http://www.mrp-engineering.com/pages/4/index.htm

I already have the K-MAC bushings and they seem to work fine, but I am very curious about the adjustable camber arms. To me, somehow the adjustable camber arms seem like a better solution, but I really don’t have clue about suspensions and my opinion could be totally wrong. Considering the longevity of these cars, I am especially curious about long term stability of the parts. I just wanted to get some guidance from some suspension gurus.

#2 12-30-2003, 09:02 AM

I sell both K-Mac and my own camber arms. For the price my camber arms are a great option. The K-Mac kit is nice because it comes with additional toe adjustment. The k-Mac is nice for mild lowering, but when you lower the car significantly the camber arms are the only choice.

ksing44 · #3 12-30-2003, 10:30 AM

Yes the K-MAC toe adjustment is nice, but my 1995 E320 already had an identical OEM eccentric bushing, except that the bushing wasn’t red polyurethane. I didn’t bother to install the toe bushing since it was the same, so it was just a waste of money in the kit.

Back to adjustable camber arms vs. the K-MAC eccentric bushings. Ok, I understand that the adjustable camber arms provide more range for adjustment, but I was more concerned about the longevity of the parts considering the substantial forces that must be exerted on the bushings or arms during hard cornering. Is either set-up better suited to withstand the punishment? For the K-MAC bushings, everything depends on the eccentric bolt hardware that sits inside the polyurethane bushing in the lower control arm. For the adjustable camber arms, my understanding is that the arm simply replaces one of the OEM links, so the sites of attachment on the suspension must be up to the task. I suppose the arm is unlikely to stretch from the forces being applied and the threaded adjustment of the arms should be adequate to withstand the forces, but do the adjustable arms have some kind of bushings that could fail from the extreme forces? Do the adjustable bars have some kind of bushings that wear out?

gsxr · #4 12-30-2003, 12:27 PM

My opinion is that for street use, stick with the K-Mac bushings. The adjustable arms, which are the turnbuckle style IIRC, don't have the rubber (or poly) bushings on each end to absorb vibrations. I recall a thread elsewhere that mentioned the adjustable arms were better suited for race use where they will be inspected very, very frequently and replaced at the first sign of stress failure.

I personally plan to install the K-Mac bushings when I rebuild my rear subframe. I don't intend to get the camber near zero. With my car lowered about 1.5 inches, I'm only at -2.x degrees rear camber, which isn't that bad for tire wear, and is good for handling. The K-Mac should get me to -1.0 which is just fine with me. If you insist on getting near zero, then you may need the adjustable camber arm, but again I wouldn't use those on the street, at least not for a daily driver... maybe a show car?

Just my $0.02...

ksing44 · #5 12-30-2003, 01:00 PM

Thank you gsxr. That is exactly the kind of information that I wanted to know. You made very good points about possible vibration and the required careful inspection of parts intended for the track.

Now that you mention it, from pictures I’ve seen, it looks like the OEM links have some kind of rubber bushings that cushion the connection points. In comparison, it looks like the MRP Motorsports’ aluminum camber arms have rigid ends. The description of the steel arms, however, mentions that there is a polymer bushing. From the picture it looks like there is a bushing on one end, but not on the other.
http://www.mrp-engineering.com/pages/4/index.htm

How long to you think the K-MAC polyurethane bushings and eccentric hardware will last?

need2speed · #6 12-30-2003, 01:07 PM

Quote:

Originally posted by gsxr
My opinion is that for street use, stick with the K-Mac bushings.

As usual, I believe gsxr gives good advice...

I thought long and hard on which way to go as well, and settled on the K-Mac kit.

An adjustable camber arm cannot be as strong as the solid arm it replaces. It is also exposed and subject to greater wear and damage. The K-Mac bushings are protected and subject to less physical stress when installed.

OTOH, those colorful anodized polished camber arms sure look sexy....can't say that about the poly bushings. :p

gsxr · #7 12-30-2003, 01:50 PM

From the photos, it looks like the aluminum arms have solid mounts on both ends - not great for street use. The steel ones appear to have a stock type bushing on one end, which is better. The poly bushings (K-Mac, etc) should last a long time, IMO - no reason not to AFAIK. BTW, I really like their front sway bar brackets! The stock ones are pretty flimsy. They were redesigned but even the newer ones aren't reinforced like that. Here's a photo of old vs. new OE:

http://www.meimann.com/images/mercedes/W124_sway_bars/sway_bar_brackets.jpg

#8 12-30-2003, 03:03 PM

Thanks for you positive inputs on my parts. I really appreciate it.

On the steel arms the goal was to allow for some compliance with the polymer bushing on the inner camber arm. The steel arms and joints are far more stronger than the OEM stamped metal. The polymer bushings are replace able and cost less than 12 dollars. I also supply replacement hardware that is grade 8 or better. This is your best compromise between performance and comfort while having maxium adjustability. These can aslo be made from aluminum arms, anodized red, clear, blue, black, orange, purple, green.

The aluminum arms with rod ends on both sides are better suited to the track and lighter chasis vehicles. i.e., 201 chasis cars. I recomend the other camber arms for W124 chasis vehicles.

Retail on the K-Mac kits are $320, but are avaiable for much less. And they are a great product to maintain that OEM apearance.

IMHO, there has not been any appreciable difference in feel between the two, though.

gsxr · #9 12-30-2003, 03:15 PM

Those steel arms might be OK for street use... that is tempting, and a little cheaper too. Mbracer, are the "polymer " bushings hard like polyurethane? Or softer like the OE rubber? Just wondering how much "give" there is for street use, I'd want a decent amount of vibration absorbtion. FYI, the stock camber arms have been superceded by Mercedes several times, the current part number is a W210- prefix and is double-boxed steel setup. Still not as stiff as yours I'm sure, but much better than the original wimpy arms used in 86-89 or so!

omegabenz · #10 12-30-2003, 03:49 PM

Does anyone have pictures of the Kmac kit? I know how it works but I've never seen good pictures of it.

#11 12-30-2003, 03:56 PM

The formulation is a little harder than a Shore "A", 80 durometer

need2speed · #12 12-30-2003, 04:23 PM

Quote:

Originally posted by omegabenz
Does anyone have pictures of the Kmac kit?

daulia71 · #13 12-30-2003, 05:14 PM

I have a 94 C280 with 18" AMG wheels with 225/40/18. I did cut the stock springs and it lowered the car almost 3", no gaps between tires & fenders. I guess it's a little extreme.
So, should I get the bushing or the adjustable arms to correct the chamber?
Anything I have to replace for the front chamber?
If somebody already explains these, I am sorry for being an idiot

omegabenz · #14 12-30-2003, 05:20 PM

Don't feel stupid! I have asked many questions on this board, and I have also answered questions. I knew nothing about mercedes about 3 years ago, all that I knew is that I was going to own a mercedes dealer at some point in my life. Have been telling my mom this since I was 3 years old. So dont feel like that.

If you lowered your car and did not get an alignment I would highly suggest putting in the Kmac bushings because you can wear out those rear tires in a hurry. Sometimes you can get the front wheels to get within like C36 or C43 or sport alignment. Hope this helps.

daulia71 · #15 12-30-2003, 07:32 PM

I guess I am gonna go with Kmac,
-Who has the best deal that I can buy it from?
-How much the cost of the labor to put it on?
-Do I need to replace other suspension components while I am installing the Kmac (to save some labor)? My car has 103,000 miles.
Thanks everyone!

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