jacking point vs yield/creep

[Tmoose]

On a Volvo forum a discussion has emerged to types of lifts that might be used in a serious enthusast's garage. One listmember has commented on the wisdom of storing a vehicle on the non 4 post lift long term, was challenged, and replied with a very broad statement thusly.

" it's the frame-bending that it causes leaving a car on a 2-post indefinitely."
- Aside from the obvious possibility of immediate damage when I select bad lift points with any lift or jack, is that comment supportable?

The same poster (who supposedly will be purchasing a lift in the next few months) also said "the people trying to sell
me hoists tell me the same, and given that the 4-post is cheaper I don't see motivation for them to do that. It's also supposed to be potentially bad for suspension too."

I can picture a naked fully extended poorly chromed shock shaft eventually developing rust in a region that would rip up seals, but don't recall any shock or strut that would be un-chromed in the working travel region.

 

[MikeHalloran]

I thought a typical 2-post lift had articulaling arms that could reach out far enough to support a car at its designated four lift points. ... and provides a little more access to the bottom by having fewer posts than the cheaper lift, which requires less steel because of lower bending moments per post.

However, I'm not sure that the support points of the car are designed for long-term storage. For old cars, sure, but today's cars are sort of super-optimized for weight, and generally don't have structure where there's not a formal use case for having it.



Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

" a typical 2-post lift had articulaling arms that could reach out far enough to support a car at its designated four lift points"

Of course it does, otherwise you'd have to be very good at determining the cg. You do risk damaging amodern car if you don't lift at the lift points, cosmetic damage to the rockers mostly.








Cheers

Greg Locock


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