HAHA, that is why I have not said any thing.

 

So I'm not the only one...

I got this truck last year and it doesn't see a lot of miles as I typically only use it for occasional hauling, so I haven't had to do much to it. I got a bigger jack to be able to work on it, and went to rotate the tires a few weeks back, like you. This is not an easy vehicle to lift! Most cars and SUVs I have dealt with have a good front jack point like a subframe or other frame member. Not here.

I jacked on the front axle where the manual showed to do it for changing a flat tire, but I could not get a jack stand in there too and when I put the jack stand on the notch in the radius arm as the shop manual showed, the axle lowered right back to the ground. I kinda gave up at that point, but I'm going to give it another shot soon. I think the only chance is to block up some wood to the frame and jack from there. Then a jack stand will work OK (I have some big ones for this too). I'll give that a whirl and see.

I saw the warning not to jack on the pumpkin, as I have seen for other vehicles, so I wasn't about to try that. On our exploder in the rear I jack on the axle tubes (as the manual shows) and place stands directly under the rear spring mounts on the axles. That works well. I was planning to try that for the rear of this one too, but never got that far as the front really had me stymied.

And yeah it's a bit heavy up front. I can't imagine what the lifting one with a diesel must be like with a floor jack.

 

Yes, and there was also a mention of a "flaming encounter". I'm leaving that one alone.

 

I never heard of a pumpkin 'til I got on this forum but I have been lifting cars by the diff, third member, bango, whatever since the fifties but I guess they aren't that strong now days.

 

I guess it's where you grew up, I was in PA when I started messing with cars (around 1957) and they were pumpkins. the first time i heard the term third member I had to ask what it was. And I'm with you on lifting with them. My sons an engineer. He builds bridges but I guess the math is the same. I gave him the problem and he just laughed saying there was no way an axle housing designed for 9000lbs was gonna bend lifting 4000 no matter where you put the jack. My 01 was a 4x4 and I lifted it probably a hundred times in 8 years using the pumpkin on the rear and the pumpkin and the axle housing on the front with two floor jacks. No ill effects as far as I could tell. My guess is thet Ford put that in there for someone who would put 9000lbs on the back of the truck and then try lifting by the pumpkin. That might stress the housing, didn't think to ask my son that one.

 

The point that you and your son are missing about axle tubes and diff housings is that they not all parts are necessarily designed to carry 9000 lbs. Look at an axle structurally from the outside in: start at the wheel. The wheel is carrying half the load of that axle. Now work you way in from there. What's next is the springs, just a couple inches in, and then the shock. That is where the load is transferred from the wheels to the frame - springs, and to a lesser extent the shocks for reactive forces. And it is a short span from wheel to spring perch vs from spring perch to center of the pumpkin, which has a significant bearing on the problem (shorter spans are stiffer and can carry greater loads for the same size structural member). Everything inboard is just along for the ride. The diff housing is nominally an unstressed member of this system, so therefore it wouldn't likely be designed to handle the full load of the vehicle. Now will it see dynamic loads in use? Sure - some, especially when one wheel sees a bump that the other doesn't. but they would be substantially lower forces than what is transferred through the springs and shocks to the frame.

Obviously Ford has seen problems from doing it, or they wouldn't warn against it. Plus others on this thread have said they have seen the issues happen. I'll find a way to jack it from the frame and I'll know it's safe. It just make lifting this beast harder. And means - obviously - I need to get a bigger garage with a 9000 lb lift in it!

 

I started shade treein' about 1960 and back then and for the next 30 years the "bango" was plenty strong.

 

So I got inspired and had some time...so I went to rotate the tires.

Figured out how to lift it reasonably, but the tires were stuck on from corrosion (maybe the first time anyone tried to take them off...) so I'll let a shop fight them off the first time and then I can grease the spindle/wheel interface like I do on all my cars to prevent this in the future (I use high temp brake grease for that).

But here's how I lifted it incase it helps anyone else:

Started front driver side. This was the trickiest corner as the diff is kinda in the way. I made a block of wood about 10" long and 5-6" high out of 2 pieces of wood, screwed together so they wouldn't slip. The top piece was about 2" wide to fit easily into the slot on the radius arm. Lifted the drivers side from the radius arm notch (near the rear of the arm) and got a jack stand under the axle in the position the manual describes (just outboard of the diff housing there is a flat for this). When using a block of wood like this, double check that the load is centered on the jack's lifting pad before you start going up. Otherwise it could be unstable and slip off.

Pic of the drivers side stand:


To get the stand under there easier, I put a second jack under the axle to lift it a bit more so it would fit under there. I'm only lifting the axle weight with the second jack, the one on the radius arm is supporting the corner of the truck.

Here's the pass side radius arm jack point (basically same as driver's side):



And here's where I put the pass side jack stand - on the axle, just inboard of the radius arm mount:



For the rear, the only decent place to jack that allowed room for a jack stand was just outboard of the diff housing, placing the stand under the spring perch (sorry for the blurry image):



The pass side was a little tougher as the gap outboard of the diff was tight, but I was able to jam the block in there. A slightly more narrow block would fit better here. No pic of that side.

Hope this helps somebody.

-Dave

 

Bango, that must be a left coast term. I say that because I see you're from CA. I don't think I've ever heard that. At least not applied to a differential. I think though we senior citizens are out numbered on this subject. It is a position that's a little hard to defend with the prohibition in the owners manual. I'm betting it's not in there because the axle housing is gonna bend. It's probably a CYA in case the truck slips off the single jack. Oh well, I agree with you, its plenty strong enough and it's my truck and if I break it I break it.

 

Yea, they are probably afraid the jack is going to slip off the banjo, differential, third member, axle housing, or pumpkin.