Rear: Where to jack it up? - PeachParts Mercedes-Benz Forum

Ceristimo · #1 03-26-2015, 11:21 PM

I know this question has been asked a gazillion times, but I've never found a clear answer on this:

Is it allowed to jack the rear of a W123 up at the differential? Like so:

That picture I found on this forum, but in that picture that jack is placed there just to SUPPORT the differential. Can you jack it up completely like that, though?

And if the answer is: "Yes, no problem", should I use a little block of wood to cushion it with? The cup on my jack is a lot smaller then in that picture, and I would be afraid of all that weight resting on three tiny points on the differential and then either poking a hole, or denting the diff.

Or is the diff so sturdy that it shouldn't be a problem jacking up there, without anything in between the jack and the diff?

I know I should probably buy a better jack, but this is what I currently have and used often without a problem:

It's a 2 1/4 ton jack, with a maximum height of 15.5". I need to figure out if it'll go high enough to get both wheels on the W123 off the ground. I can jack my Mazda up with it without a problem, but I can't for instance get the wheels of my wife's Camry off the ground if I jack it up on the front cross member. I need to jack one side at a time to get it on jack stands, so I do want to get a better jack but that'll be a few more months.
I'm looking to replace my flex discs (a new topic will be opened for that one in a few weeks I guess), but first need to make sure I can jack the W123 up safely.

vstech · #2 03-27-2015, 12:04 AM

Yes, no problem.

ON A W123... Or EARLY W126.

NOT ON A W124 or LATE W126...

However, I would not use that jack... To unstable. Go to harbor freight and spend $50 for a 1.5 ton full size jack...

gatorblue92 · #3 03-27-2015, 05:12 AM

Quote:

Originally Posted by vstech

Yes, no problem.

ON A W123... Or EARLY W126.

NOT ON A W124 or LATE W126...

However, I would not use that jack... To unstable. Go to harbor freight and spend $50 for a 1.5 ton full size jack...

Where do you jack the W124 from? I used the jack under the diff on my 300TE last year and it didn't seem to hurt anything but if its not recommended then where?

vstech · #4 03-27-2015, 08:56 AM

Quote:

Originally Posted by gatorblue92

Where do you jack the W124 from? I used the jack under the diff on my 300TE last year and it didn't seem to hurt anything but if its not recommended then where?

The diff mounts on the 124 are fragile... Use the jack points on that chassis... Or use a bar, and jack up on the diff mount/subframe.

mach4 · #5 03-27-2015, 11:12 AM

On any project requiring work under the car, safety is a primary concern. Jack stands are kind of OK but I like to use cribs...a lot more sturdy and steady.

Just a thought

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Ceristimo · #6 03-27-2015, 12:11 AM

Except that there is no harbor freight in Alaska. Wish there was, they seem to sell a lot of good, cheap tools. I've never been to a harbor freight store

I was hoping to get away without having to buy another jack. I've never had an issue with this jack, but you're right: it is quite small.

Would this be good jack?:

http://www.amazon.com/Maasdam-PowR-Lift-MPL1449HD-Green/dp/B003EIKBW2/ref=sr_1_3?ie=UTF8&qid=1427429866&sr=8-3&keywords=green+jack+foot

Rogviler · #7 03-27-2015, 01:18 AM

Have you got a ditch? Before mine got crunched I had dug a trench specifically to change the flex discs (though I was going to use it for other things too). It's certainly the safest way to work under a car.

Of course I'm betting the ground is still frozen up there at the moment...

-Rog

TnBob · #8 03-27-2015, 05:25 AM

If thats your rear end, I sure hope you are replacing the plug with a brass one plus a dab of anti seize.

Yes, using the diff works well and with your jack Id suggest adding a 2x4 across it.

Doesnt HF ship to AK ? Home office is in Calif so you would sure think they would.

Ceristimo · #9 03-27-2015, 01:10 PM

The thing is:

I don't like jacking a car up either. When I have it on jack stands, I always have an extra pair of jack stands under the car near by, and rims stacked on both sides underneath the vehicle. I value my life much more than I value the car.

For this reason I bought 12-ton ramps that I use a lot. But, when doing the flex discs, you need to rotate the drive shafts, so the wheels need to be off the ground.

So, this'll have to be done on jack stands.

Unless someone has an idea on how to do the flex discs with the car on ramps?....

mach4 · #10 03-27-2015, 01:50 PM

Quote:

Originally Posted by Ceristimo

...when doing the flex discs, you need to rotate the drive shafts, so the wheels need to be off the ground.

So, this'll have to be done on jack stands.

Actually only one rear wheel needs to be free to turn. In my crib situation, I'm entirely comfortable with jacking one rear wheel 1/2 inch up off the crib for the time necessary to rotate the drive shaft. that. If the floor jack were to fail it would just settle back to the crib.

Rogviler · #11 03-27-2015, 02:29 PM

Yeah, I'm also much more comfortable working in a trench with just one wheel off the ground than jack stands or one jack or whatever supporting most of the car's weight. It would be impossible for the car to fall past a certain point that way. A stable elevated platform would be the next best thing.

-Rog

Ceristimo · #12 03-27-2015, 02:52 PM

@Rogviler
I always use two jack stands per corner of the car, one support the weight, one placed very close nearby underneath something sturdy as backup. I have rims stacked up under both sides of the car as well. This way it can never drop past a certain point either.
A trench is not an option. I've got 5 inches of ice and snow on my drive way right now and the ground's frozen.

I have 12-ton ramps, so I have a stable, elevated platform. Point is though, how to get one wheel off the ramps then...

@mach4
That sounds like a good idea actually. Where can you safely jack one wheel up? Where would you place the jack?

mach4 · #13 03-27-2015, 03:01 PM

Quote:

Originally Posted by Ceristimo

@mach4
That sounds like a good idea actually. Where can you safely jack one wheel up? Where would you place the jack?

I place the jack on the lower A-arm as close to the tire as possible. I'll sometimes jack on the differential but you'll get tire droop so you've got to jack higher to get the wheels the same height off the ground. I also happen to have two floor jacks so I can keep the car mostly level while jacking.

Ceristimo · #14 03-27-2015, 03:14 PM

@Mach4
Thanks! I'll go and give that a try tomorrow. I'll put Betsie on ramps, and see if my jack goes high enough to get the tire off the ground. If it does, than I can do the flex discs on ramps, which I would certainly prefer over jack stands.

I have two jacks as well (they are both the same cheap AC Delco jacks) and generally use them for support in combination with jack stands etc... I have never tried to jack up a car simultaneously with 2 jacks. I wouldn't know how to lower both of them at the same speed, at the same time.

Also, lower A arm = trailing arm?