Safest car jack capacity?

I've got no problems with the rear jacking point. I use the regular, somewhat cupped cradle, with a wood piece (2x4x4) in the cradle, and a hockey puck atop.

Chock both front wheels fore and aft, nothing's going anywhere. The jacking point may be a little off-centre, but seems to work fine.

 

I prefer not to use the axle, since if it is bent, it might change the rear wheel alignment. The rear jacking point is not centered, but enough centered to allow both rear tires to clear the pavement.

 

IF you bend that rear axel by jacking up the car, you have a serious problem!

If you're doing a transmission fluid change, and the car is tilted, you can't fill it correctly.

 

The safer alternative would be to jack up under the rear spring seat and rear shock attachment point.

 

No difference in safety by jacking in the middle.
Then you can put the jack stands on the axel.
"IF" that axel was so weak that it would bend if you jacked the car up by it, it would have bent
While you drove it.

 

I'm gonna stay out of this.

 

Yes, you need a flat top adapter plate. A 2-1/2 inch riser will probably be needed to get both rear tires off the pavement when the jack reaches it's full height.

 

They are custom made items. We are making a few but cannot sell them here.

A newer version of he flat top aluminum low profile racing jack that you see in my attached photos is often sold for $60 with widely available coupons. The original shown sold for $100 nearly 15 years, ago.

1.5 Ton Aluminum Rapid Pump® Racing Floor Jack

 

You're welcome.

Using a pinch weld adapter like the one shown, you can jack up the front enough to get both the front and rear tire on one side above the pavement. This is ideal for rotating tires. I would, however not recommend getting under the car supported by the jack only.

 

Then, if you need to move the front tires from the right to the left as recommended in the pattern shown, you can use it to jack up both front tires to do just that.

 

I picked up this flat rubber cradle to occasionally sub for the conventional cradle on my jack:

Floor Jack Saddle | Princess Auto

All the cradles are pin in socket, and I think the diameter is pretty consistent. Verify before you buy.

One thing I found with the above link, it had a weld bead around the base of the pin, that prevented it seating properly. I made a washer out of 3/4" medite that accommodated the weld, still allowed the pin to lock.

 

It won't hurt to raise one side as long as the lift is stable and you don't get in the car or load or unload it. The chassis is stiff enough to take it, if all you are ging to do is to change and rotate tires.