Proper use of floor jack and jack stands with a 123-chassis 240D: place where, how? - Page 2 - PeachParts Mercedes-Benz Forum

toomany MBZ · #16 02-26-2007, 07:26 PM

Quote:

Originally Posted by Ara T.

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 understand using the factory jack lifts the car up, on one side only, of course, and the indy rear will drop to it's travel limit. Using the diff [as I have done on every vehicle I have owned without any known difficulties] I cannot detect any dissimilarities raising entire rear end. I might be missing something. I also use the engine cross member as well in front. Too cheap to get rubber pads, so I use wood cushions, and keep a length of 4X4 in trunk, so if I have a flat, I don't need to wind jack so far, and gives a bit more surface area on ground.

pawoSD · #17 02-26-2007, 07:32 PM

All the more reason to drive a G-wagon......its high enough to lay under when not even on jack stands.

85chedeng300D · #18 02-26-2007, 08:57 PM

I think there is a special tool/attachment that is inserted on the hole that is used when jacking an MB with a non-MB jack. I remember seing it in the MBbraingear website. I can't remember the part # though. Has anyone used or saw it?

Scott98 · #19 02-26-2007, 09:09 PM

Quote:

Originally Posted by R Leo

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.

I do the same exact thing. In fact, I shake it quite vigorously. If its going to fall, I want it to fall then and not on me.

Such a simple test could save your life. It almost seems stupid not to do it. (not trying to insult anyone here)

Scott

p.s. If you live in California you most definitely ought to do it.

Ara T. · #20 02-26-2007, 10:19 PM

I always wonder what would happen while im under there during a nice earthquake.

Oh well, at least i'd be doing something I like.

I could think of other things I'd rather be doing though...

Mustang_man298 · #21 02-27-2007, 12:08 AM

While shaking the car helps to verify it, it is not foolproof, and neither are the ratchet type stands. I do agree they are a bit more solid in design, however I had a close call that tested my faith in them. I have always been somewhat of a believer in overkill with supporting cars-which ended up being my saving grace. I was helping a friend part out an old 70's Ranchero, he wanted the rear end pumpkin out of it, I had the car up, had shaken it quite well, stands under the axle by each wheel on solid concrete. Good to go? I thought so anyway, being my typical self though, I did my usual just in case move of placing the jack back under the diff housing and bringing it up to contact. Crawled under, shaking and banging getting those nuts off the rusty studs, cursing, got a piece of pipe to smack the gasket loose and BANG! the whole car shifted with a good thunk. I flew out and assessed what happened, the jack had caught the car and saved me, one of the stands had failed, there was a roll pin in the handle part that held the ratcheting pawl in place to the handle, that pin had sheared, letting the lever fall down & look like the pawl was fully seated, and it had actually only caught on the tip of it and had finally slipped. That stand was retired from service and its mate was thoroughly inspected (they were not harbor freight cheapies either). Point is, you can never be too careful, and constant inspection of things is your best defense against failures.

Scott98 · #22 02-27-2007, 12:11 AM

Quote:

Originally Posted by Mustang_man298

the jack had caught the car and saved me
Point is, you can never be too careful, and constant inspection of things is your best defense against failures.

I also always keep the jack under the car as a back up safety device. You can never be too careful. Glad you weren't hurt.

Scott

JimmyL · #23 02-27-2007, 12:15 AM

Quote:

Originally Posted by Scott98

I also always keep the jack under the car as a back up safety device. You can never be too careful. Glad you weren't hurt.

Scott

I "third" that very sound advise.

rino · #24 02-27-2007, 04:05 PM

Thank you so much, you all, for sharing your wisdom here...
So, to recap your suggestions:

1) To lift front: floor jack under the engine cross member just behind the oil pan.
To lift rear: floor jack under the differential (or, optionally, under the subframe
mount area). (Are we positively sure the FSM allows for using the differential
this way on a 123-chassis 240D? Could someone please check that...)
Always place buffering in the form of rubber or wood block (2x4) between the
floor jack's saddle and the car. QUESTION: Do you secure the wood to the
jack's saddle in some way of just place it on it? It would seem to me that, if
not secured properly to the saddle, chances are the wood might slip during
the lifting, when things are likely to move a bit around...

2) Place jack stands under the frame box just inside of the jack holes (front set of
holes when lifting front, rear set of holes when lifting rear), buffering the
contact areas with wood (like a 1'-long piece of 2x4), unless you have a
rust corrosion problem in that area. AWAYS test for any instability by shaking
the car hard before getting underneath! ALWAYS keep the floor jack under the
car in light contact with the frame at the lifting point as a back-up safety
device! The manual for the jack stands I bought warns strongly against using
the jack stands to lift just the left or right side of the car, and says to ALWAYS
use the jack stands in pair to lift EITHER the rear OR the front side of the car. Do
you second that? QUESTION: It occurs to me that a car placed on jack stands
this way causes the contact area between the frame of the car and the saddles
of the stands to be at an angle, therefore not firmly seated on them. Wouldn't
it make more sense to place some wood (or use other means of lifting) under
the tires on the opposite side of the car, so that the car now sits level on the
jack stand saddles and not at an angle?

Also:

Quote:

Originally Posted by winmutt

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.

Sure, but when you place the rear on jack stands, putting the car in gear and using the parking brake doesn't do any good... The only thing that can be done in that case is chocking the front tires (I have a set of 4" wooden ramps, with chocks nailed to them, that I plan to use under the front tires when putting the rear end on jack stands (and viceversa). That will also raise the front (or rear) end in such a way as to provide a flat (level) contact area between the saddles of the stands and the car.)

#25 02-27-2007, 04:38 PM

Quote:

Originally Posted by R Leo

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.

Raising a vehicle is an excellent situation for doing things by the book. EVERY two post lift ever made has instructions exactly like that. You are supposed to raise the car clear of the floor and give it a shake. Same goes for jack stands.

I spent lots of time in my Dad's Independent Garage in the fifties in Killeen. That was when I was from about the age of five to about 10. He made the rules about going near a car that was lifted in the air QUITE clear. As a result of these instructions and him practicing what he preached, we are both still alive with no missing limbs.

It sounds like R Leo is trying to fill in some of the gap of no longer having Deezel, the self appointed Safety Officer. Keep it up!

winmutt · #26 02-27-2007, 04:55 PM

Quote:

Originally Posted by Scott98

p.s. If you live in California you most definitely ought to do it.

If your in cali just stick to ramps!

winmutt · #27 02-27-2007, 04:58 PM

For the jackstands I'll stick with metal on metal.

Sugi · #28 03-01-2007, 12:19 AM

I also had a bad run in with a Ranchero-1971. I thought I had learned my lesson when I dropped a 1962 crew cab VW truck off a skinny little floor jack onto my nose (wheels were on thank God) when I was 18. Well, 16 years later I had to learn the lesson again. I'll leave the story at trying to pull a transmission out and using non-cool (ok, concrete block, DOH, idiot, I knew better) materials on top of ramps to get a little extra clearance. Luckily I had my craftsman tool box (4 drawer Rally box, all metal) under there. I had pulled the pan on the tranny, disconnected the linkage and I wiggled it-and hit neutral. No parking brake on, car rolled...When the car fell, it landed on my box; leaving just enough room for my head. A neighbor jumped the fence and got the car off me with the floor jack. I still get flashbacks thinking about it. Now I'm back to my paranoid ways. I always slide the unbolted rims under the car at various points. Big huge jack stands. Leaving the jack in place. Parking brake on even if all 4 wheels up. Cell phone in pocket in hopes that I could use it if something did happen. I grab the wheelwell and try to knock the car over before I get under it! Don't get in a hurry like I did and forget everything you know you should do.

p.s.- banged that toolbox out with a hammer and it still works ok as a backup. Nope, won't tell Sears to make a commerical about it- don't want to advertise my stupidity! Rancheros and El Caminos are cool but evil...

~Sugi

vstech · #29 03-01-2007, 03:51 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 · #30 03-01-2007, 07:07 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?