Proper use of floor jack and jack stands with a 123-chassis 240D: place where, how?
 

What areas of contact do you use in order to avoid damaging anything in the delicate frame of the car and its components? Do you place any wood as buffer between the lifting devices and the car? Is it wise to use two blocks of hard wood (I already have two sets of 4"-high, secure wooden ramps that I have been using) under the wheels on the side opposite to the one placed on jack stands (with chocks nailed on the blocks of wood to improve stability and safety) in order to keep the car level so that it will be flat on the lifting devices' contact areas and not resting on them precariously at an angle?

Please contribute any useful ideas that come to mind relevant to this topic, and please make it as clear as possible, even at the risk of being redundant (I am using these tools for the first time and, given the potential danger involved in working under a car supported this way, learning how to do it safely is of foremost importance to me...)

TIA,
Rino

I just use the area directly under the holes that you would use the crappy factory jack. I have a rubber pad on my jack but in certain circumstances I will use wood blocks.

I have also placed jackstands under the control arms in the past.

One thing I would not do is jack the car by the differential. Not on an independent suspension car anyways.

I dont think this is the correct answer by a long shot. There are "hardened" point under the car for jacking etc. If you look on the side of the car there is a u shaped channel that hangs down, towards the front tires it has a reinforced end. Towards the rear tires there is a metal plate that is bolted in to the hard point. Both of these are fairly easy to spot. I wish I had a pic to show. The only problem is jacking and then putting stands. Usually I get a nice 2' section of 2x6 and run it under the rest of that U channel. you can lift the whole side of the car this way. Perhaps someone else can chime in on jacking but thosejack stands belong under the hardened sections. Also when jacking always have something softer than metal inbetween. Always chock your tires and always put the car in gear AND use the parking brake. If the parking brake has not real effect then fix that first.

To raise the car, I use the factory jack in the factory holes. Then I put a jack stand under the frame at the jack hole. I use a small piece of plywood as a cushion between the stand and the frame -- see photo (I enhanced the lighting so you can see the jack hole). Because of the way the jack works, it doesn't get in the way of the stand, and vice-versa. I repeat the operation for each of the four locations on the car that I need to have off the ground.

I have also used a floor jack under the jack hole position but then I can't get a jack stand in there and don't want to risk putting it somewhere else. I don't know how strong the rest of the frame is.

Some day :D I'll remember to take a picture of the jack and the jack stand in position together.

Why? That's where the FSM says to lift.

Don't make this to complicated. It's not rocket science.

For the front I use the engine cross member just behind the oil pan to jack the car.
I place the jack stands under the frame box just inside of the jack hole provided by Mercedes. Been doing it this way since I have owned Mercedes, 27 years with no problems.
Look at this post, second page. Those are the 6 ton jacks at Harbor Freight.

http://www.peachparts.com/shopforum/diesel-discussion/122057-617-engine-replacing-oil-separator-check-valve-upper-oil-pan.html?highlight=oil+separator+pan+dave

For the rear I use either the subframe mount area or the differential. I usually place the jacks under the subframe mount area.

Ara T. Don't see why you consider the differential sacred. Ive owned the 300TD for 16 years and have jacked it at this point ever since I got my long reach floor jack about 8 years ago. When I rebuilt the rear suspension. The differencial mount was in fine shape. replace it anyway because I was doing a complete rebuild. But it did not seem overstressed. Remember the differencial is mounted with 4 bolts to the subframe. So the force is on the subframe mounts and the differential mount at the same time. Not just the differential mount alone.

Jeremy5848

Please consider getting another set of floor jacks. I had a set like that quite a few years ago and had the lower straps snap when placing the SL on them. For $25 or so you can get a set of 12 ton jacks at Harbor Freight. I know that HF is not necessarily the best but a set that holds 12 tons should be good for a 2 ton car.

Dave

Sweet I'll start jacking mine that way front and rear (diff in rear).
Thats precisely the area I was talking about.

Make sure and be careful around the jack points if they are rusted, like mine though. Safer to use the frame, IMHO.

x2. I had those same jack stand and have got to say, they are no good. The narrow base combined with the pin-through-hole design made me very nervous when using them.

Interesting advice...
 

My set is at least 30 years old and show no hint of a problem -- maybe they build them cheaper now? But I like the kind you guys are suggesting -- the ratchety feature is nice -- so maybe I'll go shopping.

I use the cross member behind the oil pan as well.

I have never used the diff on any car, unless the FSM allows it. I typically use the control arms if I am just raising one wheel off the ground a bit, being that it has to deal with the sprung and unsprung weight.

I have a pair of old cast iron/steel ratcheting stands. Each one holds 6000 lbs. Get rid of those whimpy pin held ones. Ask my father how it felt when one of those gave way in the 70's.

And safe!

FWIW I always leave the jack jacked up just shy of the bottom of the car near where ever I am working. Even jacktands wobble....

Whenever I place a car on stands, I remove the jack from underneath then give the car a good, solid bump at each corner with my hip to detect and test for any instability.

Anal? Nope. I have still vivid, 6 year-old's memories of my dead neighbor's legs and feet sticking out from underneath his car after it fell on him one Saturday afternoon.

Whoa. That's terrible :eek: