JHZR2
Staff member
So in tool time we discussed the jackpoint brand jack stands, and there is a thread here about jack stands on unibody frame rails. Lots to learn to be smart and safe.
We know how jacks can damage pinch welds and underbody coatings... But what about bending stresses?
Thinking out loud here about putting cars up, especially lifting high enough to get on jack stands. I've read where body to frame weld points have broken, some cars are stuff and short enough that lifting up one wheel causes the other one on the same side to also come off the ground.
There are lots of stresses on by vehicle, especially when lifting up only one quarter of it, high enough to get the wheel off the ground, or even so high that something can be put under it (jackstand).
But what about bending/misaligning/ruining mounts and bushings/putting oddball stresses on the vehicle?
I've seen this said both ways... Do or don't jack up on the control arms, subframes, subframe mount points, jack points, differentials, engine cross-braces, etc, etc. what's right? What approaches will damage the vehicle, be it damage to the structure, or else just misalignment? What's truly right or wrong?
A lift picks the vehicle up evenly all at once. The weight distributions differ by vehicle, so it's not 1/4 mass on each, but they all lift at the same rate. Jack a car up, you can have one quarter a foot higher than another. Mostly all bending stresses, as the suspension only takes up so much.
So how much is too much? What is damaging and what isn't?
I'm thinking that short of a real lift that picks up a vehicle evenly on four points and unloads the suspension, the best thing may be to get four of those ultralight HF aluminum jacks, which while not the strongest/safest by themselves (I reviewed one once), would share the load four ways.... And then jack with four jacks, one at each official jack point, and get it up so the vehicle is lifted at all four corners at once... Then put it on four jackpoint jackstands.
Good idea? Expensive I know, but anything else puts irregular and inconsistent forces on the vehicle, essentially bending it (even if it is stuff enough to lift up together).
Is this way overthinking it? After reading the frame rail thread and realizing how weak so much of the individual areas of the car are, it really has me wondering...
Thanks for reading my book here!
We know how jacks can damage pinch welds and underbody coatings... But what about bending stresses?
Thinking out loud here about putting cars up, especially lifting high enough to get on jack stands. I've read where body to frame weld points have broken, some cars are stuff and short enough that lifting up one wheel causes the other one on the same side to also come off the ground.
There are lots of stresses on by vehicle, especially when lifting up only one quarter of it, high enough to get the wheel off the ground, or even so high that something can be put under it (jackstand).
But what about bending/misaligning/ruining mounts and bushings/putting oddball stresses on the vehicle?
I've seen this said both ways... Do or don't jack up on the control arms, subframes, subframe mount points, jack points, differentials, engine cross-braces, etc, etc. what's right? What approaches will damage the vehicle, be it damage to the structure, or else just misalignment? What's truly right or wrong?
A lift picks the vehicle up evenly all at once. The weight distributions differ by vehicle, so it's not 1/4 mass on each, but they all lift at the same rate. Jack a car up, you can have one quarter a foot higher than another. Mostly all bending stresses, as the suspension only takes up so much.
So how much is too much? What is damaging and what isn't?
I'm thinking that short of a real lift that picks up a vehicle evenly on four points and unloads the suspension, the best thing may be to get four of those ultralight HF aluminum jacks, which while not the strongest/safest by themselves (I reviewed one once), would share the load four ways.... And then jack with four jacks, one at each official jack point, and get it up so the vehicle is lifted at all four corners at once... Then put it on four jackpoint jackstands.
Good idea? Expensive I know, but anything else puts irregular and inconsistent forces on the vehicle, essentially bending it (even if it is stuff enough to lift up together).
Is this way overthinking it? After reading the frame rail thread and realizing how weak so much of the individual areas of the car are, it really has me wondering...
Thanks for reading my book here!
