how to use jack and axel stands?!?
how to use jack and axel stands?!?
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Discussion

torqueofthedevil

Original Poster:

2,088 posts

207 months

Tuesday 18th May 2010
quotequote all
I have some axle stands and have a pretty good idea where to put them under my 306.

However, as you are not supposed to put one under one side then jack the other side and put it under that - how do you do it? I have a trolley jack but how am i going to safely jack the whole of the front of the car up evenly and get them under?!?!

TheEnd

15,370 posts

218 months

Tuesday 18th May 2010
quotequote all
you can do it one side at a time, but you'll need to return to the first side and reset the stand as they tend to build up leaning forces which you'll need to relieve.
It would be quicker to jack the middle from the engine subframe or similar (no the sump) but you'll need to find something load bearing first, rather than just jack anything metal under the car

Monkey news

1,076 posts

211 months

Tuesday 18th May 2010
quotequote all
If you have a haynes manual, then it will tell you where you can jack the car up from. If you can find a load bearing point on the centeral part of the car this would make life easier. But do not just jack the car up from any metal object, such as the sump wink

reggie82

1,377 posts

208 months

Tuesday 18th May 2010
quotequote all
TheEnd said:
you can do it one side at a time, but you'll need to return to the first side and reset the stand as they tend to build up leaning forces which you'll need to relieve.
eek

I've always jacked up the car one side at the time and never releived the leaning forces - am I lucky to be alive? Didn't know about that!

TheEnd

15,370 posts

218 months

Tuesday 18th May 2010
quotequote all
reggie82 said:
TheEnd said:
you can do it one side at a time, but you'll need to return to the first side and reset the stand as they tend to build up leaning forces which you'll need to relieve.
eek

I've always jacked up the car one side at the time and never releived the leaning forces - am I lucky to be alive? Didn't know about that!
You don't always see it, but next time you jack the car, head back to the first side, lift gently until the car just lifts off the stand, and see if the head of it kicks over a little.

It might not happen all the time, it might only be certain cars, and the higher your first lift, the greater the effect will be,
but it short, the car tends to pivot and slide away a little on the second side, trying to make the first stand lean out away from the centre.

the science...

Imagine a flat object, like a paving slab, where the edge is, is quite clear, but when you lift it on one side, say to about 45', the spot directly under that edge, straight down is now 6 inches in from the side.
Exactly the same way a crane reaches something close to the body by lifting the boom up closer to vertical, rather than retracting the jib bits.

when you go to lift the other side, it will pivot again in an arc until the slab is level over the front, but the first stand still has it's base 6 inches in from the side, and is trying to lean / fall over

You aren't tilting to 45', but over-exaggerating helps you to visualise the forces at work , just in smaller amounts.


Deva Link

26,934 posts

275 months

Tuesday 18th May 2010
quotequote all
It's a good idea to put the wheels under the sills too - then if the car comes off an axle stand it'll collapse onto the wheel and not you.

reggie82

1,377 posts

208 months

Tuesday 18th May 2010
quotequote all
TheEnd said:
reggie82 said:
TheEnd said:
you can do it one side at a time, but you'll need to return to the first side and reset the stand as they tend to build up leaning forces which you'll need to relieve.
eek

I've always jacked up the car one side at the time and never releived the leaning forces - am I lucky to be alive? Didn't know about that!
You don't always see it, but next time you jack the car, head back to the first side, lift gently until the car just lifts off the stand, and see if the head of it kicks over a little.

It might not happen all the time, it might only be certain cars, and the higher your first lift, the greater the effect will be,
but it short, the car tends to pivot and slide away a little on the second side, trying to make the first stand lean out away from the centre.

the science...

Imagine a flat object, like a paving slab, where the edge is, is quite clear, but when you lift it on one side, say to about 45', the spot directly under that edge, straight down is now 6 inches in from the side.
Exactly the same way a crane reaches something close to the body by lifting the boom up closer to vertical, rather than retracting the jib bits.

when you go to lift the other side, it will pivot again in an arc until the slab is level over the front, but the first stand still has it's base 6 inches in from the side, and is trying to lean / fall over

You aren't tilting to 45', but over-exaggerating helps you to visualise the forces at work , just in smaller amounts.
As soon as you mentioned it, it made perfect sense - I just had never considered it before.

You may have just saved my life one day lol

agent006

12,058 posts

294 months

Tuesday 18th May 2010
quotequote all
I've always had more problems getting the car back down off the axle stands. Aforementioned side loading forces seem to have a lot more effect on the remaining stand on the way down. Sadly neither of my cars have a central member (hurr hurr) to lift by.

EDLT

15,421 posts

236 months

Tuesday 18th May 2010
quotequote all
The 306 has a crossmember just behind the engine that can be used as a jacking point, however, just behind that is another crossmember-like piece of metal the really really can't be used as a jacking point.

On most cars a good central (ish) jacking point is where the rear gearbox mounting attaches to the subframe. Be sure to put the jack under the area where the bolts go and not on the mounting itself as some are made of alloy and not very strong.

Ozzie Osmond

21,189 posts

276 months

Tuesday 18th May 2010
quotequote all
Deva Link said:
It's a good idea to put the wheels under the sills too - then if the car comes off an axle stand it'll collapse onto the wheel and not you.
Yes, that's what I do - "just in case".

Too many people have died under badly supported cars.