sounds silly, but...hard to raise M3 using scissor jack?

[xanatos]

So this is going to sound weird, but then again that's why I'm posting here, so...

I have a big red 1.5 ton scissor jack that I used to keep in my MS for emergency cases.
I have raised the MS a few times using that jack and it works fine. I have also tried using that jack on an Odyssey and that worked fine too.

Recently sold the MS and got the M3. Tried the same jack again on this car, and for some reason it is very hard to lift.
I keep turning the screw and have to put in massive amount of effort just to make it turn and lift the car. In fact I had to stop because I was having to turn it so hard that I was afraid something might break.

I thought maybe jack is bad, so I tried it on the Odyssey again, which is a much heavier car, and it works fine, very easy to turn the screw and lift. Tried it again on M3, same issue, very hard to lift.

This is just bizarre to me, since M3 is a lighter car by almost 1000 lbs so I see no reason I should have any issues. I ran out of ideas, so maybe someone here might have experience lifting the M3 using scissor jack? BTW I am already using the proper jack pad so I don't think that is the issue...

 

[Daniel in SD]

It's trigonometry. The Model 3 is a lower car. When the scissor jack is in a lower position it requires fewer turns to achieve the same vertical travel and therefore more force.
Another issue is that the Model 3 is more stiffly sprung than a Honda Odyssey or Model S. If you try lifting the car yourself (or maybe not because you might bend the fender) I think you'll find that you can lift either of those cars higher than you can lift the Model 3. Or maybe just pushing down on the fender would be easier. Either way it takes less force to change the height of the car.

 

[xanatos]

It's trigonometry. The Model 3 is a lower car. When the scissor jack is in a lower position it requires fewer turns to achieve the same vertical travel and therefore more force.
Another issue is that the Model 3 is more stiffly sprung than a Honda Odyssey or Model S. If you try lifting the car yourself (or maybe not because you might bend the fender) I think you'll find that you can lift either of those cars higher than you can lift the Model 3. Or maybe just pushing down on the fender would be easier. Either way it takes less force to change the height of the car.

Thanks so much, I would never have thought of that, but makes perfect sense!
So I wonder then if I should get a different scissor jack with a higher weight rating in hopes that it will require less effort to lift, or if there is some other solution for using scissor jacks with M3...

 

[Daniel in SD]

Thanks so much, I would never have thought of that, but makes perfect sense!
So I wonder then if I should get a different scissor jack with a higher weight rating in hopes that it will require less effort to lift, or if there is some other solution for using scissor jacks with M3...

I've got a VW/Audi one with a custom adapter and it does feel a bit sketchy when I lift the car.
Like this: 99-05 VW GOLF PASSAT AUDI A3 A4 A6 JACK WRENCH POUCH 8L0011031A | eBay
Looks like someone is selling pad adapters: Tesla Model 3 jack pad adapter for Audi/VW jack | eBay

 

[apsen]

I thought maybe jack is bad, so I tried it on the Odyssey again, which is a much heavier car, and it works fine, very easy to turn the screw and lift. Tried it again on M3, same issue, very hard to lift.

I don't know which Odyssey you have but my 2000 Odyssey EX is only 100 kg heavier than my M3 AWD.

100 kg is about 5% of the weight.

 

[VT_EE]

It's trigonometry. The Model 3 is a lower car. When the scissor jack is in a lower position it requires fewer turns to achieve the same vertical travel and therefore more force.
Another issue is that the Model 3 is more stiffly sprung than a Honda Odyssey or Model S. If you try lifting the car yourself (or maybe not because you might bend the fender) I think you'll find that you can lift either of those cars higher than you can lift the Model 3. Or maybe just pushing down on the fender would be easier. Either way it takes less force to change the height of the car.

This comment on the stiff suspension is so true. I rotated my tires this weekend using a low-profile floor jack. I had both wheels on one side off the ground before I had it high enough to get the jack stand legs on.

 

[Garlan Garner]

I've tried many jacks and have had the worst experience with scissor jacks because of the weight of the vehicle. Teslas are heavy cars.

I would never try and loosen any bolts or anything of the sort while the car is on scissor jacks. If you just have to use a scissor jack...at least invest in some jack stands...so that all of that weight won't be on the scissor jacks.

 

[Daniel in SD]

I've tried many jacks and have had the worst experience with scissor jacks because of the weight of the vehicle. Teslas are heavy cars.

I would never try and loosen any bolts or anything of the sort while the car is on scissor jacks. If you just have to use a scissor jack...at least invest in some jack stands...so that all of that weight won't be on the scissor jacks.

That’s why you’re supposed to loosen the lugnuts before you lift the car... and fully torque them after lowering it until the wheel touches the ground.
I don’t think you need a jack stand to change the tire. Just don’t put any body parts under the car.

 

[run-the-joules]

That’s why you’re supposed to loosen the lugnuts before you lift the car... and fully torque them after lowering it until the wheel touches the ground.
I don’t think you need a jack stand to change the tire. Just don’t put any body parts under the car.

indeed. I break the bolts loose with the jack in place and having juuust started to lift the car, then hand-tighten before lowering, and torque wrench once down.

I swap my snow wheels/tires on and off for ski trips, I'm down to a bit under 25 minutes for a whole change… gonna get an impact gun and see if I can trim some time off!

 

[mswlogo]

Keep in mind that if you have a flat tire the car is even LOWER.

I bought a used aluminum scissor jack for an older Porsche. Seems to be a collectors item as there are tons of them on ebay.

See here The perfect Model 3 emergency jack?

 

[Daniel in SD]

indeed. I break the bolts loose with the jack in place and having juuust started to lift the car, then hand-tighten before lowering, and torque wrench once down.

I swap my snow wheels/tires on and off for ski trips, I'm down to a bit under 25 minutes for a whole change… gonna get an impact gun and see if I can trim some time off!

I’ve got a dewalt cordless impact wrench. 1200ft*lbs of torque at the highest setting, you better make sure it’s turning the right direction or it will sheer the lugs off the hub. It’s awesome.

 

[Glamisduner]

How do you use a jackpad adapter with a scissor jack?

 

[SageBrush]

It's trigonometry. The Model 3 is a lower car. When the scissor jack is in a lower position it requires fewer turns to achieve the same vertical travel and therefore more force.

Huh. I'll have to pull mine out tomorrow. I keep seeing the opposite in my head

Addendum:
The jack forms a right triangle, and the hypotenuse does not change.
As we rotate the arm and the jack rises the x value shortens and the y value increases but the relation
x^2 + y^2 = R^2 stays constant. The x shortening per rotation is constant.

Say we start at x = 6 and y = 1, then R = sqrt(37)
If we shorten x by 1 then x = 5 and y = sqrt (37 - 25) = sqrt (12)
If we shorten x another 1 then x = 4 and y = sqrt (37 - 16) = sqrt (21)
And another 1 for good measure: now x = 3 and y = sqrt (37 -9) = sqrt (28)

The vertical gain per decreases increases as the angle opens.

 

[SageBrush]

The vertical gain per decreases increases as the angle opens.

Errr .... that should be the vertical gain per rotation decreases as the angle opens.
I'll check my arithmetic and calc with paper and pencil tomorrow after some sleep. My experience keeps telling me the opposite -- that it is harder to lift as the car is higher.

 

[apsen]

Errr .... that should be the vertical gain per rotation decreases as the angle opens.
I'll check my arithmetic and calc with paper and pencil tomorrow after some sleep. My experience keeps telling me the opposite -- that it is harder to lift as the car is higher.

Er... The less gain per rotation - the less force you need.

 

[mswlogo]

Huh. I'll have to pull mine out tomorrow. I keep seeing the opposite in my head

Addendum:
The jack forms a right triangle, and the hypotenuse does not change.
As we rotate the arm and the jack rises the x value shortens and the y value increases but the relation
x^2 + y^2 = R^2 stays constant. The x shortening per rotation is constant.

Say we start at x = 6 and y = 1, then R = sqrt(37)
If we shorten x by 1 then x = 5 and y = sqrt (37 - 25) = sqrt (12)
If we shorten x another 1 then x = 4 and y = sqrt (37 - 16) = sqrt (21)
And another 1 for good measure: now x = 3 and y = sqrt (37 -9) = sqrt (28)

The vertical gain per decreases increases as the angle opens.

He’s right.

Think of it when the jack is near the full height. When you crank the jack, the height changes very little (most leverage). At the bottom it’s the least leverage (height changes a lot for each crank, least leverage).

 

[SageBrush]

^^
Yeah ... I think he is correct although I cannot reconcile the math with my long time experience that it gets harder to crank as the car is lifted.



I set the hypotenuse to 8. The slope increases as X approaches 8

 

[CUBldr97]

I have a 3 ton scissor jack, works great

 

[Daniel in SD]

Yeah ... I think he is correct although I cannot reconcile the math with my long time experience that it gets harder to crank as the car is lifted.

Maybe you’re getting tired
As you lift the car the weight supported by the suspension decreases.

 

[SageBrush]

As you lift the car the weight supported by the suspension decreases.

I'm unclear how suspension plays into this but you are certainly right that until the tyres come off the ground some of the car's weight rests on them.