Jacking under diff question.

The great gmt400 “block the front wheels or don’t block the front wheels” conflict. Brother fought brother, father fought son. A forum divided.

Or you can do like I do for the best results... park the truck on uneven wet grass when jacking. You'll get a rolling scissor jack that doesnt roll, a bottle jack that only sinks, a high-lift bumper jack that tilts sideways once both tires are off the ground, and jack stands slowly return to the earth if they need to hold a load over night

You guys are thinking too new here. I still have the original bumper jack for my 76 Trans Am. I don't trust it at all. Reason being, and I'm not afraid to admit this, is that I really don't know how to use the thing. Maybe it's incomplete, maybe it doesn't function correctly, but as to the point of the OP... definitely not using a bumper jack on a rear diff.

Ahhhh @RichLo you beat me to it....

Why not just jack it up from the axle tube with an adapter? I'd use a floor jack over a bottle jack if you're lifting from the pumpkin.

My two cents for what it's worth. I've never hesitated to jack under the diff on solid axles such as the 14bolt and have yet had an issue from it. Floor jack is preferred but I've used a bottle jack as well. Stay low and use appropriate means to support the load as soon as possible (stands, blocks, etc.).

I generally block the front wheels on the front side beforehand if I'm lifting the rear and readjust once it is lifted and stable. Once supported, I block both sides of the wheels for good measure (my driveway is also sloped). I've become much more safety conscious since getting married and starting a family. Don't want to leave them cleaning up pieces or getting hurt from my poor decisions.

termite said:

My two cents for what it's worth. I've never hesitated to jack under the diff on solid axles such as the 14bolt and have yet had an issue from it. Floor jack is preferred but I've used a bottle jack as well. Stay low and use appropriate means to support the load as soon as possible (stands, blocks, etc.).

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Can you remember the diameter at the top of the bottle jack? My 5 ton jack is only around an inch in diameter where it lifts.

termite said:

I generally block the front wheels on the front side beforehand if I'm lifting the rear and readjust once it is lifted and stable. Once supported, I block both sides of the wheels for good measure (my driveway is also sloped). I've become much more safety conscious since getting married and starting a family. Don't want to leave them cleaning up pieces or getting hurt from my poor decisions.

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Ditto, I'll be working (nose down) on an incline. Chocking will be thorough!
Only lifting the height of tyre sidewall deformation - and briefly - is a big relief. Original plan was to be lifting the whole back end of the truck to let the axle droop. Glad that idea was banished before implemented.

Pinger said:

Can you remember the diameter at the top of the bottle jack?

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I don't remember the size of the bottle jack since it's been several years. I primarly use a floor jack which still only contacts a small area given the shape of the housing.

If it makes you too nervous, you can lift each side individually as mentioned previously by others.

why not jack it under the anchor plates?

eran tomer said:

why not jack it under the anchor plates?

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Lifting it in the center is so convenient. One lift, and both jackstands go under.

1998_K1500_Sub said:

Just set the bottle jack on a creeper... easy peasy.

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Pipes




although thats a 1976 14 bolt I would say that I didnt break it doing this