Transmission cross member Warning & Information

[adsm08]

That's may be true but not necessarily the case. Jacking the diff means the load is distributed differently. The load is pushing down on the outside of the axles while the support is in the center, which looks to bend the axle housings. I'd bet there's deflection of the axle by jacking at the diff., which the axle may be able to withstand if it's beefy enough. Actual experience is important but I'm not sure if engineering would support differential jacking.

I concede that jacking at the diff will change the stresses on the axle, but the weight to strength ratios of the axle on most trucks vs the weight of the rear of the truck makes the change in stress fairly negligible.

I have had my truck airborne, come down hard, and not damaged the axle. This is a 7.5, which isn't particularly strong as axles go. I have seen a 9.75 get bent by a kid and all the old seasoned techs were standing around trying to figure out what kind of force it must have taken to do that.

 

[Sasquatch_Ryda]

They get lifted everyday at every shop around the world that uses drive on hoists with center lift jacks by the center of the diff.

I do it day in and day out....as does everyone else that works at the dealership I'm at.

 

[85_Ranger4x4]

Some vehicles have offset diffs which would make things goofy to jack from.

Other vehicles have the diff cover actually stick down over the case (Fords usally don't) and you will mess the cover up.

I only jack per side, I had an incident a couple years ago with both rear wheels off the ground and off the truck. Things shifted somehow and it ended up with the axle on the ground and the bedside against the wall. I was under the truck shortly before it did that. Front wheels where blocked too, but it slid the blocks.

So now I try to do things one wheel at a time as much as possible. My brother is a Ford tech and irritates him because it takes longer but I don't care.

 

[Rearanger]

So now I try to do things one wheel at a time as much as possible.

Absolutely, diff lifting should only be done to install stable and safe supports on each wheel.

 

[85_Ranger4x4]

Absolutely, diff lifting should only be done to install stable and safe supports on each wheel.

It wasn't by the diff, it was sitting jackstands when it fell off.

Major bummer because it pinned the jack between the spring and the floor. Had to get the loader tractor and pick the truck up by the hitch.

I just really don't like having more than one tire off the ground at a time.

 

[SMTGREG]

I have repaired more than a few leaks from the rear cover because someone had misplaced a jack on the diff and bent the rear cover.