Searched through the forum did not find my answer. Other on-line searches were not very fruitful.
1. Can I use the differential as a jack/lift point with my floor jack?
2. I am guessing it is best when lifting and supporting the rear end, the jack stand should be placed basically between the u-bolts used for securing the rear-end to the leaf springs. Would that be correct?
3. I am wanting the rear end higher than the front end for what I am going to work on. Am I ok to simply block the front tires or should I lift the front end and get it as low as possible, but still on stands.
4. If I can't use the differential, then I am guessing you would use the point on the axle closest to where I plan to place the jack stand.
Hopefully I won't get flamed too bad on this post.

 

Good questions! Especially when it's a matter of personal safety.

I use the pumpkin as the jacking point when lifting both rear wheels. If only one side, then the jacking point is directly under the spring plate on the axle tube.

For raising the entire vehicle, the rear stands are located under the axle tubes. The fronts tires are parked and chocked on some wooden blocks (16-inch square "pads" made of cross-nailed, 2x6 lumber, three levels high). I still leave the jack loosely under the pumpkin.

Personally, I am not comfortable being under a rig completed supported by only jackstands.....I'm in earthquake country!

 

Like HIO, I like leaving one end on the ground "if possible". Can't always, but if you plan on jerking things around, four jackstands can get kinda "wiggly". Not bad if you are only working on the outside of truck. Underneath, I always error on the safe side.

You have the good points covered. Don't worry, you won't get flamed for asking things about safely working under a truck.

Now if you asked "How many bumper jacks does it take?.............you might get some slack.

 

I don't recommend the pumpkin as a jack point, neither does ford.
Your putting all the weight on a center point. It's a pita but I alternate sides.

 

I don't get to use jack stands to often but I got plenty of other stuff to use.......

 

I recently had all 4 corners of mine up in jacks. The rear I put under the axle, between the ubolts. In the front I used taller stands and put them on the flat part of the frame. It was on flat concrete and was very stable that way. I tried hard to wiggle it down and push it over, but it was solid.

 

A vehicle can't fall off of a jack or stand it isn't on.

I always try to leave as many tires as practical on the ground. Like others have said, up on all 4 corners on jacks can be a little wiggly. If I'm only rotating tires I'll do it. In this pic I'm only adding taller rear blocks so the springs are not being removed. I put my 6 ton jack stands under the front of the springs. Another place would have been on the frame where the jack stand can cradle the frame and is limited from slipping by the shackle mount. Where I just described is where I put them when I removed the rear springs. And like most people, the removed wheels going under the truck. Gets them out of your way and I'd rather have a lot of mass under the truck with my doughy body than without.


When I removed my front end I put my 12 ton jacks under the frame, using the rear spring mount bracket to keep it from slipping forward, and left the rear tires on the ground.



This view shows it best, this is is why tires on the ground are more stable than the sturdiest of jack stands.


And yes, I bought a pair of 6 ton and 12 ton stands, and a 20 ton bottle jack just for this project. My 3-1/2 ton floor jack is good for single tire lifts or raising the rear end under the center pumpkin, but it will not lift the front end with out creaking and twisting.

Right or wrong, I've always jacked empty vehicles from the middle if I needed both wheels up.

I spent a lot of time under my 5.0 Mustang with the comparatively piddly 3 ton stands. Not with this beast.

Mr. HillCountry, your questions and concerns are solid and welcomed.

 

Yeah tell me about it. Them power strokes weigh A LOT in the front. I've got a 99 CC LB 4x4.

 

Hillcountry, Hio and I are prolly the 2 biggest joksters on this forum. And as noted above neither he,myself, or anybody else would flame you on a question of safety. Best to keep all safe in this brotherhood. All the above are good points for you. I ALWAYS keep the jack loosely under it's jacking point and the tires I've removed under the vehicle.
And LeoJr... I got a big o' kick out of your "1st alert" version in your pic #3. I don't know if it's redneck or just plain handy, but Jeff Foxworthy would be proud of ya.

 

That's funny!! My wife walked out and saw that and had a 'what the heck' moment too.

Fluorescent tube are extremely straight, I used them pressed against my rotors to get a good basic toe alignment while it was easy to adjust everything without the tires being on the ground.

I use these on my scooter to make sure the rear tire is in alignment with the front.

Being used on the scooter or the truck, admittedly it looks very odd...

 

"JEFFFAFA, seems you have too many Fs"...says Peanut?

 

Never thought about you guys in shakey country and your additional concerns. Admittedly they had a "earthquake" 600 miles to the north in OK recently.
I am serious about safety myself. Just not knowledgeable about best practices around these old trucks.
Now, how many bumper jacks would it take to safely lift and support an F100. I am guessing four (:

 

Please don't use bumper jacks unless you increase your life insurance and name me as your beneficiary. They are very unstable.

 

A lot of junkyards/ u-pull-it, or pick-a-part use rims welded together to support the vehicles in the yard. They are pretty stable.

 

^ yup they are good to have laying around. Great to have along with wood blocks most jack stands won't be big enough to lift my truck high enough to change axles. Need to invest in some high lift jack stands