Safely lifting the rear.

[OneForTheRoad]

Has this ever happened? Sounds like one of those urban myths.
Most manufactures recommend using that as a jacking point. Diffs are normally cast metal, one of the strongest points.

Don't know , don't care , it's not worth the risk tbh.

 

[ALFAitalia]

The term "spreading a diff" is not usually to do with damaging one...you have to some times spread a diff.... with the right tool.....when fitting locking diffs etc. Never heard of a steel dif being damaged. However I could not lift on the rear axle on my Grand Cherokee as it had a D44a axle... which had an aluminium dif housing.

Differential Housing Spreader | OTC Tools

otctools.com

 

[Bellow]

The term "spreading a diff" is not usually to do with damaging one...you have to some times spread a diff.... with the right tool.....when fitting locking diffs etc. Never heard of a steel dif being damaged.

I know that - but it makes clear that a diff casing can distort. With that comes the risk of upsetting bearing pre-loads. Also, diff mounts are designed to resist drive torque and isolate vibration. There's nothing to suggest supporting half the weight of the car is within that brief.

 

[ALFAitalia]

Fair enough... your car your choice....but after being in the trade for many years I've NEVER seen...or even heard of come to that, of a dif casing distorted through jacking. And there is nowhere near half the weight at the back on most big engined Mercs. And what choice do I have of I want to jack both rear wheels off the floor at the dame time on my 212....apart from the jacking points there is nowhere else to jack and I can't jack there if I want to put an axle stand there either side. My ALFA was superior to the Merc as far as jacking goes at there were jacking points on the sills as well as other ones for workshop lifts....meaning I could jack at one point and put the axle stand under the other. It's even worse on the A Class...no rear dif and nowhere else to jack except the rubber pads by the sill. To do the handbrake today I had to use two jack's.... not ideal by what's the option?

 

[Trickythemerc]

I have been jacking under the diff for 50 plus years and never cracked, broken or stretched anything apart from my back muscles.

 

[Wearsthefoxhat]

Has anyone got a link for the correct rubber jack pads that sit on top of axle stands , mine are cracking a bit .

These are the ones I purchased, and from this seller… have been fine and used fairly often. Bought the insert ones from here too…

 

[Bellow]

Fair enough... your car your choice....

My choice - or I follow the guidance in the OEM workshop manual and jack under the axle tubes.

but after being in the trade for many years I've NEVER seen...or even heard of come to that, of a dif casing distorted through jacking.

You wouldn't. It'll be a diff failure (bearing, ring gear, etc) 10,000 miles down the road that no one can explain.

And there is nowhere near half the weight at the back on most big engined Mercs.

Mercs aint the only cars on the road. And, it won't be far off half on a RWD. 60:40 weight splits are the preserve of FWD.

And what choice do I have of I want to jack both rear wheels off the floor at the dame time on my 212....apart from the jacking points there is nowhere else to jack and I can't jack there if I want to put an axle stand there either side. My ALFA was superior to the Merc as far as jacking goes at there were jacking points on the sills as well as other ones for workshop lifts....meaning I could jack at one point and put the axle stand under the other. It's even worse on the A Class...no rear dif and nowhere else to jack except the rubber pads by the sill. To do the handbrake today I had to use two jack's.... not ideal by what's the option?

Those cars were never designed with DIY maintenance in mind. Whatever we think of that, it's for the DIYer to find ways in the absence of full OEM workshop kit. Such is life.

 

[ALFAitalia]

Axle tubes are what I used on my Grand Cherokee.......but next to no modern cars have live axles and axle tubes....just drive shafts that you def cant use!

 

[Bellow]

Axle tubes are what I used on my Grand Cherokee.......but next to no modern cars have live axles and axle tubes....just drive shafts that you def cant use!

All true.
Last year in another thread we had a go at jack and axle stand at the same point (designated jacking point) and couldn't make it work (height issues). If, I was jacking the rear of a RWD car with independent rear suspension I'd look at the diff subframe as a potential lifting point - considering constructing a cradle if that would help. Alternatively, under each lower wishbone simultaneously (or an incremental version) to gain height for stands - as per your A-Class(?) But with a live axle I don't have to.

 

[del320]

I did not realise this was such an arcane subject, so will be glad to be further enlightened.

On my C124 there is a large rubber bung well inboard of each jacking point.



I can easily wind the car up on the admittedly flimsy MB jack, then slide a hefty axle-stand behind - locating it on the substantial bung.

I then go round and do the other side. Is this feature not found on modern cars?

 

[ChrisPDuck]

I'd look at the diff subframe as a potential lifting point - considering constructing a cradle if that would help.

I haven't looked under my car to check since this thread started, but I was wondering whether this was an option. Is the subframe lower than the diff, and could a wooden spreader span the two cross-members? Are they designed for that type of vertical loading mid-span?

 

[ChrisPDuck]

I then go round and do the other side. Is this feature not found on modern cars?

Hmm - there are what look like removable plastic panels inset into the side skirts on my 2010 S212. I shall have to investigate to see if there are jacking tubes there. From memory though I only have the factory scissor-type jack that locates into the plastic recesses on the underside, so I'd need a different tool if there are indeed jacking tubes in the sills.

 

[ChrisPDuck]

These are my stands , the black pad fits both nicely
View attachment 168630

The recess in my axle stand adapter is 60mm x 64mm - would it sit on top of your axle stands? If not, what size would the recess need to be?

 

[W1ghty]

The recess in my axle stand adapter is 60mm x 64mm - would it sit on top of your axle stands? If not, what size would the recess need to be?

I think the top of the Halfords ones are 50mm wide , but when I was moving garage stuff around a couple of hours ago I found 2 more pads I had bought a few years ago and never used .
I appreciate the offer of help though , thanks buddy .