Even if you did bend the axle tubes, I have to seriously doubt that you bend them enough to cause any problems. People have done this for years, I practically grew up in a garage and never have heard that. Let it be everyones own decision where they place the jack when lifting their vehicle. No hard feelings to anyone, I just really doubt that it is possible to bend the axle tubes.

 

Totally agree there, if you think about 100% of the rear weight sits on the axle tubes. You could take your axles off and jump on, drop heavy stuff on ect the axle tube and that will still never come close to the 2500 lbs that sits on the tubes. Also agree that its everybody own opinion.

I looked for wall thinkness a while back to and could never find it, its wierd. I think I read something along the lines that it might be just a hair under 1/2 but not positive.

 

I remember on my rear diff (C9.25), it has almost a square part on the bottom of the diff that is perfect for a jack. So that's where the jack goes. Its personal preference in on this topic though.

 

Y'all are not considering two things:

1) the rear weight of the vehicle is split between 2 points (2 tires) when it's on the ground and concentrated at a single point (1 diff) when jacked in this manner.

2) the stressing of the tubes occurs over a very short distance (hub to spring pack) in the first case and over a much greater distance in the second (diff to spring pack).

Some guy explained it better than I could:

I have to disagree with you there. When the car is on the ground, the weight of the rear half bears on the rear wheels through the ends of the axle tubes. There is some down force on the differential from its own weight and the weight of the rear of the driveshaft, but the majority of the force is probably the bending force from the spring-to-wheel distances reduced by the leverage of the longer section of axle tube from the spring to the diff.

When the car is jacked up by the differential, the stress on the axle tubes at the junction with the differential is multiplied by roughly the square of the ratio of the differential-to-spring length over the spring-to-wheel length, since the leverage is reversed. It becomes clearer if you focus on the point of greatest strain - the axle tube attachments to the differential housing.

Mike

Some links from 6 years ago on this very topic:

http://www.google.com/group/alt.auto...ct=result&cd=1

http://www.google.com/group/rec.auto...ct=result&cd=2

I've never had much faith in the corporate 9.25 ... if I had a D60 I would probably jack it in the center and not think anything of it. I just don't trust the light duty axle I've got.

 

Good points. But why not have much faith in the 9.25? Its the biggest and strongest 1/2 ton axle that comes factory. It is very similar to a D60 housing wise. The ring gear is very large for a 1/2 ton, only .5" less than the D60. The axle tubes are similar thickness too. The D60 has 35 spline 1.5" shafts, and the 9.25 uses a 31 spline 1.31" shaft both the same type of material. The weakest part of the 9.25 is that its semi floating and uses c-clips, but that doesn't have much to do with housing stregnth.

I like our 9.25's, they're beefy for a 1/2 ton and I've never heard of any really problems with them other then bearings going bad or something