noka

I see four plastic (or hard rubber) jack lift pads with rectangular depressions that probably accept the stock jack. Two behind each front wheel and two in front of each rear wheel just inboard from the rocker panels. I will need to put my Winter wheels on (when they arrive soon). Would you recommend using stock jack to lift at these points or should I use a floor jack there? The only thing is that either the front or rear pads (can't remember now) are somewhat higher than the bottom of the rocker panels and there could be some damage if I'm not very careful with the floor jack. Anybody lefted their baby yet? Comments?

Rgds,
Norm

TC32AMG

Dont use a floor jack I did that and crushed the the area surrounding the depressions, it is just plastic. If you can somehow fabricate solid blocks to fit in the depression that will mate nicely to the floorjack then yes.

I use the factory jack, but it is not the most stable but it does work. You just have to be careful how you position the stock jack. If you place the foot of the jack too far in you may not be able to crank it properly and it may get stuck under the car had that happen this year, was a b*tch to get that jack out.

T

dsC32

My lift pads are destroyed by the floor jack, which does not have a flat face. I now put a wood block between the jack and the pads, or what is left of the pads. I am considering getting a better floor jack with flat face that would not damage the pads.

noka

I can remove the circular metal base (the thing the object typically rests on while jacking) which then leaves a relatively flat base. The question is whether that will still destroy the pads (i.e. must I come up with some device that will fit nicely in the rectangular depression in the jack pad)?

Rgds,
Norm

wingless

Please never, never, never go underneath a vehicle supported only by a jack. It is very unsafe. A jack may fail permitting the vehicle to crash suddently to the ground without warning.

Instead, raise the vehicle with a jack and then lower the vehicle onto jack stands.

The jack point and stand points must all be structural members, designed to support the weight of the vehicle.

noka

Thanks for the warning, however I am not sure how it answers my questions. I have no intention of getting under the car. I only want to jack each corner without doing damage to the car or lift points, in order to switch to my Winter wheel/tire setup.

Rgds,
Norm

KWiK

Just lift from the center jack points...

noka

No confirmation in Owner's Manual or from MB-Tech resource about a) where these lift points are, and b) if they are safe for the vehicle. e.g. some say to lift at rear diff housing and some say it will do damage. I guess I'll have to try the jack that came with the car.

Rgds,
Norm

wingless

No, it does not answer your question. But, other people look at this and may conclude that lifting a vehicle with a jack and then working on a vehicle suspended by a jack is a safe practice. It is not. It is good to promote and share safe operating techniques.

It is not horrible to change wheels supported only by a jack. But, this is not a roadside emergency. It is a planned service operation. So, under those circumstances, normal safety techniques should be used. I would not want to be holding a wheel within a wheel well when a vehicle crashes down.

It may be that there is a front and rear frame crossmember that could be used to lift with a floor jack. That would then leave these four pads available for jack stands.

Does it look like the bottom jack pad, designed for the Porsche 924 / 944 would fit into these frame pockets? If so, I could measure mine and provide the dimensions.

noka

The inside dimension of the rectangular pad is about 2.25" long. If the one you are referring to is somewhat less than that, it could work. Please let me know. (Interesting that the site says no jack pads available for '05 C55).

Rgds,
Norm

KWiK

The center jack points are not listed in your manual, but they are shown on startechinfo.com. As you can see, the rectangular pad under the front and the rear diff are used.

wingless

The width of the "nose" on the bottom jack pad, designed for the Porsche 924 / 944, is 2" and the height of the "nose" is 1¼".

The proper procedure, however, is defined by KWiK. Lift at the front, then the rear, center jack points, then place the vehicle onto jack stands. Following that procedure, these jack pads are not required.

noka

Not to be nit-picky but, first I don't see any identification of model/year that he procedure above is applicable to. I would want to know it applies to the '05 C55. Second, I heard that lifting from the rear diff could cause damage - not something I am about to try (there are some postings on this site somewhere about it). Lastly, I'm not quite sure I have a good visual of exactly where the jack should go, using the diagram above. I don't know if 1m is some diagram designation (or 1 meter)? OK, maybe I am a bit thick but better safe than sorry I say.

In any case, the length of the Posche adapter would fit in the depression, so why wouldn't that work if the MB jack would be OK to use? I know ... not tested by MB and "not supported".

Rgds,
Norm

KWiK

1. yes, you are being a bit thick. 1m is a label, read the text, look at the pic.
2. yes, this is for all W203. If you don't trust the pic, you can always log onto StarTekInfo and look it up for yourself.
3. there is nothing wrong with lifting your car from the rear diff. (see #2)

wingless

If following unsafe service practices are acceptable to you, then by all means, go for it. If on the other hand, you are "in it" for the long-term and want to remain assured that safety problems will not rear their heads, then look to constantly evaluate procedures with safety in mind.

noka

$3K a year for a subscription? I think not. I don't know about anyone else but that picture does not represent the underside of my C55. I think it is old info and perhaps not applicable to the C55.


Yes, I must agree with you there, having reviewed it again.

Rgds,
Norm

noka

According to sales at the website you provided there are differences in the jack pads between Porsche 924 and 944. Do you have a p/n of the one you have? For $15 I'm willing to order it and evaluate it. By the way, the MB dealer service manager said to use a floor jack at the four lift points and that's where they place their lifts anyway without any problem.

Rgds,
Norm

rguy

Okay, here we go.

(1) To finish another conversation that is relevant here I finally put on my winter wheels for my '05 C55. I used the '05 CLK500 Sport Wheels and they fit perfectly. I payed less than half of what they would cost new because they were dealer takeoffs. In other words, some guy wanted to upgrade and the dealer gave the guy a trade in for new wheels. Again, they do fit. They fit with plenty of clearance on fronts and backs.

(2) There is no readily accessible front or back center jacking point for the C55 AMG. Instead, there is underbody molding that shapes air flow and contributes to that slippery .27 coefficient of drag. (That is extremely low by the way)

I own a craftsman 1.5 ton racing jack (119.99 at any sears) and a 1/2" torque wrench with a deep style 17mm 1/2" drive socket for the wrench (~$80 and ~$6).

I used a 1x4 (hardwood preferred) and placed that over the jack lifting pad. I then slid the whole contraption under the hoisting points and made sure that the 1x4 would not hit the sideskirts. This board evenly distributed the load and prevented damage from occurring to the hoisting point rubber pads.

I jacked the car up at one point at a time (a total of four times) and changed wheels one at a time. Personally, I think that using jack stands for changing a wheel is a little on the extreme side. If you are doing a brake job or something like that, then sure. But the procedures described above are way too cautious for this job in the way that I am going to describe.

WARNING: This procedure in no way guarantees that you won't get injured or die from following it. Furthermore it in no way guarantees you will not damage your car, your jack, or any other living or non-living thing, repairably or irrepairably as is fit.

The above just means I am not legally or monetarily responsible if you guys do anything after reading this and screw it up or do something based on the instructions being incomplete or incorrect. (it is my sincere hope and belief that they are correct, efficient, non-dangerous, and complete)

Having said all of that, then here goes:

Before attempting anything do the following:

Put the car in park, with the parking brake on, with the car on a flat surface, and have wheel chocks that block the axle you are not working on so it cannot roll when the car is jacked up. Do not forget to turn off the anti-towing security which is the little button on the center of the dash near the hazard light switch.

(1) Work on one wheel at a time (I started at the passenger side front wheel)

(2) Take the lug wrench supplied in your spare tire changing kit (it is underneath your spare in styrofoam)

(3) Just break the torque on the lug bolts so that they are no longer torqued down tightly. You should feel a lot of resistance and then markedly less resistance.

(4) Place the floor jack with the jack's lifting pad centered under the rubber hoisting pad (about 6" towards the other wheel on the same side of the car, on the side frame rail underneath the car.) that the car has to be hoisted by a lift when it is in service.

(5) Add a 1x4 piece of hardwood to the jack's lifting pad that is about 12" long and position it so that it will not hit the side skirt or damage the wheel well.

(6) Jack the jack up until it is close to putting pressure on the hoisting pad, but is not touching it quite yet. (gap about 1/2 inch)

(7) Realign the jack with the hoisting pad and the 1x4 board with the side framerail to avoid hitting the aerodynamic sideskirt.

(8) Continue to jack the jack up until the car tire is about 1"-1.5" off the ground. Any more and you probably should use jack stands. (make sure your head is never under the car when any part of the car is lifted.)

(9) You can now loosen the lug bolts completely either by using the 17mm 1/2" drive deep socket and turning by hand or by using the mercedes lug wrench from the trunk.

(10) Be careful not lose the lug bolts and not to use the torque wrench as this can kill the calibration of the torque wrench.

(11) Now you should have all the bolts out of the wheel and the wheel should be ready to come off.

(12) Take the wheel off and put on the wheel you are replacing it with.

(13) You may want to take some care to make sure that any logos or asymmetries between front and rear wheels are going to be the same or however you like them when the car is parked and when it rolls. (I like the AMG logos to be in roughly the same orientation on the front and rear wheels so they look matched when the car is parked.)

(14) Finger tighten the bolts in a criss-cross pattern like you are tracing out a five-pointed star.

(15) Once you have done it once, then you should do it again as the wheel will have most likely moved significantly while finger tightening the first time.

(16) For the '05 c55 amg set your torque wrench to ~60 ft-lbs and tighten in a five-pointed star criss-cross pattern (essentially trace a star between the bolt holes) You might find it is easier to lower the car very very slowly until there is just a tiny tiny fraction of weight on the tire to keep the wheel from rotating when you are torquing down the bolts.

(17) You will most likely hear a click when the torque is at your setting. Immediately release torque on the wrench and move on to the next bolt.

(18) Next you need to torque the bolts to ~90 ft-lbs. This is an even split between what is in the owner's manual and what mercedes dealerships use. Again, use the criss-cross pattern.

(19) Seriously, if you aren't going to do the four tightenings, then you might as well have a dealership do the job because you won't get proper wheel torque or wheel alignment without doing this procedure.

(20) Slowly, and I do mean slowly, of course after checking to make sure nothing crawled under the car, lower the car onto the ground.

(21) Repeat procedure for other three wheels. Good luck.

(22) Retorque the lug nuts to ~90 Ft-lbs at 20 miles post-wheel change and 100 miles post wheel change as the lugs will loosen after driving on them a little bit. This happens due to vibration and other things that cannot be controlled for by any procedure. This is critical. I find the easy thing to do is reset my trip odometer after I complete a wheel change. That way when it reads twenty miles, I hope out and retorque them (3-8 minutes tops) and when it hits 100 miles, I do the same.

If you practice common sense, then you should be fine. I hope this helps you do this practically. Plan on 1-2 hrs for your first time. And for the love of God, work slow and safe. Have a good time and enjoy the few thousand dollars you will most likely save by not paying the dealer and avoid many thousands of dollars more by not getting hurt and having to pay hospital bills!

Essentially boys and girls, you should treat a jacked car like a gun. You always assume the gun is loaded and you should always assume the jack is going to fail or an earthquake is going to break the jack or something catastrophic is going to happen. This means never having anything under the car that you value, whether it is your gold watch, girlfriend, left foot. NOTHING goes under a car that is jacked. I just don't know how to explain the danger of jacking any car. Even using jack stands requires using a jack so is just as dangerous as not using jack stands in my opinion. I hope this helps you.

smgC32

I have jacked the car up dozens of time with a racing jack with a large diameter rubber pad that is wider than the two outside plastic molded jack recepticles without any issues or deformation of the stock lift component under the side skirts. As long as both sides of the plastic are evenly supported, there should be no problem.

rguy

The board is not just to keep the hoisting pad from getting deformed, but also to more evenly distribute the load on between the car and jack. But, thanks for disagreeing with me. All opinions count here.

rguy

Oh and by the way, mine are rubber. Don't know if that is a new thing or not.

wingless

The one I am using is for the 924. No I don't have the part number, but it looks exacly like the bottom image.

noka

I basically have followed the same procedure with the same type tools with my BMW's quite successfully.
Do you need to do this even if the car is unlocked (basic alarm not armed)?

I think I remember 80 ft-lb in the Owner's Manual. Do MB dealers really use 100 ft-lb?

Rgds,
Norm

noka

They said they all look like the bottom image. Apparently there are several types of varying size. Thanks anyway.

Rgds,
Norm

rguy

Books recommend 80-85, dealers use 95. I use 90.

I believe you have to use the anti-tow even if the car is unlocked. Somebody else might have a better (read more definitive answer).