Jack/lifting safe gradients?

[Mr Whippy]

My driveway area is on a slight downhill.

I’m not sure on the exact angle. I can measure to be exact.

It’s smooth tarmac.

Is there a prescribed maximum slope, or a calculation you can make to determine what’s safe or not?

Also for axle stands?

I assume a wide low entry jack is going to be most stable.


But what about chocking on a stiff car? In the past I’ve noticed a car can end up on the jack in one corner and a single wheel on the opposite corner, and thus being fairly free to rotate.
Better to lift incrementally at two points onto stands so a pair of wheels get loaded instead?



I’m being overly cautious here. A mobile tyre fitter had the neighbours car up in the air looking precarious, so I assume the slope isn’t seen as ‘too much’ by someone doing it all day long.

I’ve looked/searched online and most people just say slopes are bad, but clearly without defining things it’s a bit ambiguous.

I’d just like to know if there are any H&S style rules around this stuff?


Many thanks

[Doofus]

What do you intend to do to the car?

The only safe angle for the ground is nought.

[E-bmw]

Mr Whippy said:

Is there a prescribed maximum slope, or a calculation you can make to determine what’s safe or not?

No

[E-bmw]

Mr Whippy said:

I assume a wide jack is going to be most stable.

Correct.

[E-bmw]

Mr Whippy said:

But what about chocking on a stiff car?

What do you mean by "chocking on a stiff car" is this a sexual thing?

[E-bmw]

Mr Whippy said:

I’d just like to know if there are any H&S style rules around this stuff?

No, there aren't.

[E-bmw]

Mr Whippy said:

I’ve looked/searched online and most people just say slopes are bad, but clearly without defining things it’s a bit ambiguous.

The only definition I would say is "if it looks right, it generally is".

You basically need to put your big-boy pants on & decide what is/looks safe or not.

[Mr Whippy]

big boy pants.

In this case it’s the very smooth tarmac that’s got me thinking the most, and the gradient combined, it could all get a bit ‘movey’


I’ll have to get a nice wide jack. I threw my old one, looked a bit past it’s best and despite being low entry was quite narrow and leany, plus the lifting head was rubbish and small and chewed up rubber pads I put on it.

[Mr Whippy]

Doofus said:

What do you intend to do to the car?

The only safe angle for the ground is nought.

No dockyard jobs.

But I want to get it up enough to get a wheel off and get into the arches.

Specifically for now swapping wheels, and arch liners off to clean/inspect inner wings, clean out crap, etc.


Yeah flat is ideal.

[Pit Pony]

I once had to jack up a V6 omega on Hardknott pass in the lake district, with only a scissor jack, having put a hole in the side wall of a rear tyre.

And 3 massive rocks from a nearby wall. To put under the other three wheels.

It was pissing with rain and going dark, and I had no mobile signal.

And the locking wheel nut had been tightened by erm a tt.

[julianm]

I've got a slight slope on the drive. I lift using a central jacking point for either front or rear - the raised end being 'downhill'. Loosen wheel nuts. Handbrake on & in park or in gear. I chock the uphill wheels as well.
Jack up until it's high enough for you & lower onto 2 jack stands at the side jacking points. I usually leave the jack in place as well, but lower it until the stands are taking pressure. At this point give the car a few serious shoves to check it's not going anywhere. Wheels off & get started!
20 years of this & so far so good.
Hope this might help you.

[TwinKam]

E-bmw said:

Mr Whippy said:

I’ve looked/searched online and most people just say slopes are bad, but clearly without defining things it’s a bit ambiguous.

The only definition I would say is "if it looks right, it generally is".

You basically need to put your big-boy pants on & decide what is/looks safe or not.

The only problem with the 'definition' in bold above, is that that very much depends on who is looking. An artist's eyes are not necessarily the same as an engineer's eyes, so neither will be their assessment. This situation needs an acute awareness of physics and dynamics, not colour and shade

[Mr Whippy]

I could jack centrally but I’d need a long reach jack, and low entry, space, weight, cost.

I think I’m better with something like this?

https://www.halfords.com/tools/garage-workshop/axl...

Then just use some decent chocks and my decent axle stands (3t Sealey ones iirc)



I’ll go out in a bit and take a pic, might give people a better idea of things.

[ARHarh]

My drive is on a slope and i jack cars up all the time. Only ever jack the downhill end up though. If I need to jack the whole car up I use the garage as that is flat. Its great for oil changes as it keeps the car level and makes draining and filling easier.

[VeeReihenmotor6]

My last house had a slope on the driveway. I used a heavy duty/wide foot jack and only ever got one corner of the car off the ground. I also used wheel chocks to stop it from moving and wouldn't have gone under the car either as it always felt dodgy.

[Mr Whippy]

870/45, so 1:19 gradient…

Edited by Mr Whippy on Wednesday 3rd May 14:05