Best way to jack the rear to rotate tires?

[Norm Peterson]

almost every car sold comes with a SCREW type jack which aside from the very small base, can not (well, short of metal fatigue) physically collapse.

If they 'bend' laterally, they aren't all that stable. I won't use those things except as a last resort. Never in the driveway, when I've got something like four floor jacks in excellent condition and an older light-duty one that's in maybe "fair" condition that I'd still put more trust in for changing a tire than some of the screw jacks I've seen.

just get one of those car-flipper devices - put the car on it's roof and you can change wheels at a comfortable height and zero risk of it falling on you. Might leave a mark on the roof, but i'll buff out.

One jack, one corner at a time works just fine. No different from changing a flat . . .


Norm

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[jimmerheck]

if you had the jacking rails, you could do all four at once. I love my jacking rails.

 

[Rapid Red]

Do you have a spare? You could jack up one side, use the spare and then go at the other. That's what I would do rather than getting both off the ground.

That actually would work just fine .

 

[M.A.N.]

Taken from HoosierDaddy

For a live axle car (like my 2014) the pumpkin and axle tubes and mounts are designed to support the weight of the car. For an S550, the pumpkin does not support any load and the bolts that hold it to the car, are to support the weight of the pumpkin and hold it in place. Those bolts are not designed to support the weight of the car. Sure, anyone can get away with it....until they don't.

Are you saying that jacking up the rear of the car by the pumpkin it may shear the
four bolts that hold the pumpkin in?

 

[CJJon]

Are you saying that jacking up the rear of the car by the pumpkin it may shear the
four bolts that hold the pumpkin in?

Or more likely bend.

 

[M.A.N.]

Or more likely bend.

NO way! You could say it's not a good idea for many reasons, it may damage
the cover, it may bend a bracket, it may damage bushing or whatever [ not that
I think it would ], but I could go with it. But to say jacking up rear of car would
bend or shear them 4 bolts, sorry I have to call foul on that, not happening.

 

[shogun32]

cracking the threaded bosses is not that far fetched. In classic "you miserably failed mechanical engineering 101" the sheer load is carried by the threaded portion of the fastener, not the shank.

 

[CJJon]

NO way! You could say it's not a good idea for many reasons, it may damage
the cover, it may bend a bracket, it may damage bushing or whatever [ not that
I think it would ], but I could go with it. But to say jacking up rear of car would
bend or shear them 4 bolts, sorry I have to call foul on that, not happening.

So Ford is wrong then?

Do What Thou Wilt

 

[M.A.N.]

I know where the sheer load is, I've had several of these out.
Worked with trucks, loaders, dozers and on N&S railroad cars
for around 40 yrs. I know a little about pins and bolts breaking.

Yes it is far fetched, an airplane could crash on top of you when
jacking it up, but it's not happening.

You could stack 5 of these cars on top of each other and it wouldn't
damage the bolts by jacking it up, not happening.

 

[Norm Peterson]

Just the basic concept of using a casting as a jack point for a whole end of a car never felt quite right to me.


Norm

 

[Ebm]

Are you saying that jacking up the rear of the car by the pumpkin it may shear the
four bolts that hold the pumpkin in?

If a car manufacturer wanted to have a jack point at the differential, it would be in the manual. That's why my response said the differential wasn't designed to be a jack point. I believe the Subaru WRX (2018 model year for example) has the rear differential as a jacking point in the owners manual. The WRX rear differential also has a flat spot between the front and rear sections of the differential. So you aren't actually jacking the section up between the differential cover and the differential itself.

Refer to picture (B)

With that said, the shear strength of the bolts holding the differential in are probably much higher than needed for a floor jack on the differential as a jacking point. Bolt fatigue may eventually change this though.

A very real concern is making the differential leak or causing a differential cover bolt to strip. This is even more of a concern on an aluminum differential cover.

 

[shogun32]

A very real concern is making the differential leak or causing a differential cover bolt to strip. This is even more of a concern on an aluminum differential cover.

or the bending/twists of the diff against the drive shaft and axles. Sure the voided rubber allow much freedom of movement but I'm not familiar with the 'normal' limits of those and whether certain combinations are "impossible" under operating conditions but totally possible (and problematic) when subjected to 1800lbs of weight.

Just fashion a 'U' bracket that picks up off the IRS frame if you can't be bothered to do the sensible thing and use a friggin' stand.

 

[tcman54]

My jacking rails help a lot, also know your tires, my Firestone Firehawks can only be rotated front to back.

TC

 

[Norm Peterson]

I know where the sheer load is, I've had several of these out.
Worked with trucks, loaders, dozers and on N&S railroad cars
for around 40 yrs. I know a little about pins and bolts breaking.

Maybe the real concern here is the bushings. I can't tell what they look like from the pictures I've found, but if they're voided (which I suspect) there's probably a force direction that would tend to over-strain them locally at the voids and result in some tearing.


Norm

 

[shogun32]

but if they're voided

they are. and the hole drilled for the bolt is 2mm oversize.