Proper use of floor jack and jack stands with a 123-chassis 240D: place where, how? - Page 3 - PeachParts Mercedes-Benz Forum

vstech · #1 03-01-2007, 02:51 AM

just an extra bit of safety tip.
When lifting either end of a vehicle on rough or soft ground that will not allow the jack to roll, DO NOT CHOCK THE WHEELS or set the parking brake until AFTER the vehicle is raised!
Floor jacks need to move as much as 12" when raising, so either the jack needs to move, or the car.
I always try to have the jack on smooth level surface but it is not always possible.
also, I would not use the jack points to hold up the car, I would use the frame itself.
most floor jacks have 4 sharp points that will grip well into wood.
if jackstands are sitting at an angle, the car will slide and fall. try to get the stands so solid metal is in the saddle of the stand keeping anything from moving.
one time I was working at a used car place and in the corner of the shop was a twin post lift with a car 1/2 on the lift. the thing was saftey taped like a police scene waiting for the insurance inspector to come look. nobody went near that thing... rubber pads on metal arms mix in some tranny fluid, wait for disaster.

1983/300CD · #2 03-01-2007, 06:07 PM

Quote:

Originally Posted by vstech

Floor jacks need to move as much as 12" when raising, so either the jack needs to move, or the car.

Don't we all have the hydraulic jack on wheels?

rino · #3 03-01-2007, 07:52 PM

Quote:

Originally Posted by 1983/300CD

Don't we all have the hydraulic jack on wheels?

I assume we all do... mine has them as well... but in spite of the wheels did not roll... at all. Rather the car on top of it did... And I am in Cali. All I needed was a nice, little quake at the time of my inspections nearby the car....

So, either I've been doing things wrong (and I assume I did), or the floor jack I got is a POS...

Rino

rino · #4 03-01-2007, 07:56 PM

By the way, vstech, another thing...
I don't seem to be able to use the floor jack longitudinally with the car (if I do, then there's not enough space to pump the handle)... so I've been using the jack (under the diff and ECM) at an angle... There's no other way to do it with this jack...

Rino

rino · #5 03-01-2007, 07:47 PM

Quote:

Originally Posted by vstech

just an extra bit of safety tip.
When lifting either end of a vehicle on rough or soft ground that will not allow the jack to roll, DO NOT CHOCK THE WHEELS or set the parking brake until AFTER the vehicle is raised!
Floor jacks need to move as much as 12" when raising, so either the jack needs to move, or the car.
I always try to have the jack on smooth level surface but it is not always possible.
also, I would not use the jack points to hold up the car, I would use the frame itself.
most floor jacks have 4 sharp points that will grip well into wood.
if jackstands are sitting at an angle, the car will slide and fall. try to get the stands so solid metal is in the saddle of the stand keeping anything from moving.
one time I was working at a used car place and in the corner of the shop was a twin post lift with a car 1/2 on the lift. the thing was saftey taped like a police scene waiting for the insurance inspector to come look. nobody went near that thing... rubber pads on metal arms mix in some tranny fluid, wait for disaster.

AH! AH! Guys, you should say these things right away! Now I understand a couple of things I experienced over the past couple of days with my brand new floor jack and stands, and also understand that I got pretty close to screwing up in a big way...
The floor jack I have is small (I wanted it that way) and it is a Craftsman (so I don't think it is a POS), BUT it did NOT roll as you say it should have, and it was instead the car to slide around on it during lift up and lift down... And I did put a nice piece of rubber between the car's metal and the jack's saddle, and yes, the rubber did get oily with diff fluid and engine oil (at differential and engine cross member lift points) and yes, I had the car in reverse gear and parking brake set and even chocks into place while using the floor jack... Yesterday in particular there was a moment the car shifted around while I was lowering it on the jack stands and the saddle contact point slided from center differential to left corner of differential, with part of the saddle protruding out. Had it fallen down, there would certainly had been some damage to the car. After that close call, I've been extremely careful with the procedure, lowering it all the way whenever I detect some shifting and then lifting it again....
I am glad you wrote this last post, which clarified a few important things. So no more rubber material between saddle and car for me from now on... Are you saying that wood is all right? For instance, is it all right to place a 1-foot length of 2x4 between the saddle and the diff or engine cross member?
What do you exactly mean by not using the jack points but the frame itself?
Where exactly do you place your floor jack when lifting rear and front?
When lifting the rear, I place the stands right under the metal thing with a bolt and springs in proximity of the rear jack holes, so the saddle of the stands is grasping the metal in that area, it fits perfectly by the way. But when lifting the front, there's no metal anywhere near the front jack holes, just that frame that looks like plastic... so I place the stands right there, underneath the jack holes, and buffer it by placing in between saddles and frame a 1-foot length of 2x4. Is this all right in your book or am I doing something risky there? I have done it that way a couple of times and it seems to work just fine...

Your post is much appreciated...

Rino

vstech · #6 04-18-2007, 11:08 PM

oops, I hate it when a thread I gave info on, had followup questions and I miss them..
sorry rino.
anyway, the jack should be solid on the diff in the rear. if your jack will not reach the dif, you need a longer jack. if you are just changing a tire, using the jack points with wood as a buffer should be fine. but it is inadequate to support the vehicle to do major repairs.
on the front, I jack up with the crossmember solid on the floor jack. and use the lower arm mount to support the jackstands.
to get the jack to slide, you need SMOOTH surface under the jack, or solid wood gripped into the jack surface and wedged solid into frame, if the jack face will not grip solid onto the crossmember/diff, and the vehicle must be free to move as the jack lifts.
John

bustedbenz · #7 01-21-2008, 03:24 AM

When I'm rotating the tires (every oil change) - admittedly, I'm not UNDER the car for a particularly long time except for the drain plug - I jack up one side or the other at the front, with a floor jack and a loose wood block (2x4) right under the factory jacking hole - where the rubber jack pads would be if they hadn't fallen off or crumbled. Then, I put a jack stand under the front... well idk what it is, just inside from the wheel, maybe the spring perch? Something stable in that general area. Nice flat surface in the same place on both sides. Then I go around, put the other side of the front up the same way. Then, I jack the back by the differential (NO block of wood here, it fits perfectly on the little jack plate anyway) and generally leave it up just like that while I rotate the tires since i'm not actually under the car during that process anyway.

It's never even tried to let go that way.

**EDIT: It probably isn't the spring perch. But it's whatever that nice flat surface that fits the metal jack stands so nicely is - the jack stand probably sits three or four inches towards the center of the car from the wheel's inside rim.

TheDon · #8 01-22-2008, 05:19 PM

safe.. I was under it while doing the engine mounts.... do it all the time

buy a set of Mercedes wheel chocks

dmorrison · #9 01-23-2008, 01:34 AM

Rino

Your really putting way to much thought in to this. Be safe but you need to experiment with the setup you have. Jack the car up and place it on jack stands. Shake it and see if it seems stable. If it's stable, try jacking it up farther. I would not place the car on the highest position, it's like stepping on the top part of a ladder, just not advised. Take some time to learn your tool setup and work with it. Experiment without getting under the car and you will learn whats safe.
As shown in the picture above it is workable and safe.

Dave

carusle · #10 01-23-2008, 08:30 AM

Ramps

rino · #11 01-23-2008, 01:12 PM

Quote:

Originally Posted by dmorrison

Rino

Your really putting way to much thought in to this. Be safe but you need to experiment with the setup you have. Jack the car up and place it on jack stands. Shake it and see if it seems stable. If it's stable, try jacking it up farther. I would not place the car on the highest position, it's like stepping on the top part of a ladder, just not advised. Take some time to learn your tool setup and work with it. Experiment without getting under the car and you will learn whats safe.
As shown in the picture above it is workable and safe.

Dave

OK. My asking so many questions... it's just that I've heard stories of
people not doing it right and getting crushed under their vehicles
as a result... I never got to raise the vehicle this high with the old stands,
so I wanted to make sure I understood enough about it to be on the safe
side. Excellent advice, yours, by the way. Thanks.

Rino

dmorrison · #12 01-23-2008, 01:35 PM

Quote:

Originally Posted by rino

OK. My asking so many questions... it's just that I've heard stories of
people not doing it right and getting crushed under their vehicles
as a result... I never got to raise the vehicle this high with the old stands,
so I wanted to make sure I understood enough about it to be on the safe
side. Excellent advice, yours, by the way. Thanks.

Rino

Good approach, Always be safe. But it's time for the little birdie to get out of the nest and go experiment. If your unsure about your stability of the stands, might I suggest multiple stands. Go to Harbor Freight buy an extra set of stands, I own 4 sets of stands. 3-6 ton, 1-3 ton. At times I have used 2 sets of stands on one end of the car. My normal points and some other points "just in case". I do this when there will be a lot of shaking and movement. The second set is there for my safety. If the car falls the safety stands will probably damage the car but save me. I'll place them under the floor section or somewhere out of my way, for the job, but will support the car just in case.
Go give it a try, don't get under the car until your satisfied that the car is safe. Spend an hour or so experimenting with the stand placement.

Dave

vstech · #13 01-23-2008, 10:28 AM

ON a level surface, chocks are not needed or recommended for lifting a vehicle with a floor jack. after it's settled on the jack stands, placing chocks behind the supporting tires is a good preventative measure, but not needed. if the surface you are supporting a vehicle is not level, be VERY CAREFUL. also, if the surface is out of level in more than one plane, avoid jacking the vehicle at all.

as long as you are on a solid level surface, don't worry about chocks or parking brake, it's not necessary. just use a good pair of jack stands, and go to work.
chocks ARE needed if your vehicle is up on ramps, cause the tires could allow the car to roll.
for HEAVENS sake, be SURE the vehicle is STABLE by shaking the car firmly BEFORE you move the jack.
(hey, lets use jack for the lifting device, and stand for the holding device in our wording...)
as for where I place my stands for supporting the front of the vehicle, I place them on the FRAME of the vehicle near the LCA mounting place. there is always angles of steel to keep the stands secure. I only use wood if I have to jack up something fragile. or if I need to REALLY lift up the vehicle, like say above 24" I jack up the car, put it on stands, lower the jack, put a 4x6 on the saddle of the jack, and lift the car further, then set the steel of the stand on the steel of the frame of the car, not the body, not the jack points, the FRAME.

rino · #14 01-23-2008, 01:25 PM

Quote:

Originally Posted by vstech

ON a level surface, chocks are not needed or recommended for lifting a vehicle with a floor jack. after it's settled on the jack stands, placing chocks behind the supporting tires is a good preventative measure, but not needed. if the surface you are supporting a vehicle is not level, be VERY CAREFUL. also, if the surface is out of level in more than one plane, avoid jacking the vehicle at all.

It's a perfectly solid level surface, in my garage.

Quote:

Originally Posted by vstech

as long as you are on a solid level surface, don't worry about chocks or parking brake, it's not necessary. just use a good pair of jack stands, and go to work.
chocks ARE needed if your vehicle is up on ramps, cause the tires could allow the car to roll.
for HEAVENS sake, be SURE the vehicle is STABLE by shaking the car firmly BEFORE you move the jack.
(hey, lets use jack for the lifting device, and stand for the holding device in our wording...)

I've always made sure to test it that way first thing after putting it on stands.

Quote:

Originally Posted by vstech

as for where I place my stands for supporting the front of the vehicle, I place them on the FRAME of the vehicle near the LCA mounting place. there is always angles of steel to keep the stands secure. I only use wood if I have to jack up something fragile. or if I need to REALLY lift up the vehicle, like say above 24" I jack up the car, put it on stands, lower the jack, put a 4x6 on the saddle of the jack, and lift the car further, then set the steel of the stand on the steel of the frame of the car, not the body, not the jack points, the FRAME.

Now, this is new to me. I've always placed the stands under the frame
box, near the jack points. Why would that not be advisable? Where do you
you place the stands for supporting the rear of the vehicle?
Please keep in mind I have a 240D... I have been told in several instances
that with this model it is best to place the stands under the frame box close
to the jack points...

Rino

vstech · #15 01-23-2008, 02:16 PM

I have not had the rear of my D sedan up in the air... so I can't be specific as to where to put the stands. on my wagon, I set the stands where the lower control arm attaches to the frame. Just get it up in the air, and look for some solid steel locations that will keep the saddle of the stand from sliding. I positively never place stands on body panels. even with a 2x4, I don't like to do it. STEEL IS BEST! if you can not find a good place, you may want to build a pressure treated chunk of lumber with a steel sleeve around it to spread the load more evenly. the control arms usually have a pocket to place a stand saddle in. near a spring pocket or shock connection. not helpfull if you are wanting to work on the LCA though... look for a spot of steel. good luck. If I ever work on the rear of a sedan 123, I will take some nice pictures of where to properly support the vehicle.