I've been jacking RWD Fords by the pumpkin for years - my dad has done it for over 20 years. The key is not to jack it by the cover but by the rear of the housing where there is more steel.

 

Exactly. You can put the jack under the pumpkin but don't make contact with the aluminum cover. Many folks put a block of wood under the steel part and then put the jack under the wood, so the jack does not come in contact with the cover.

 

I have to admit that I have jacked the rear of the car by the pumpkin once. But I normally don't.

My understanding is that the reason Ford says not to use pumpkin as a jack point is because there is a risk of bending the axle tubes. Normally, road forces goes into the axle at the wheel and is then transfered to the car at the spring perch. When you jack it by the pumpkin, the load is going into the pumpkin and then being transfered to the body once more at the spring perches.

The problem is that the distance from the pumpkin to the spring perch versus from the wheel bearings to the spring perch is about three times longer. Which, if I still remember anything from my ME classes, means the bending load while jacking from pumpkin is about 9 TIMES greater than the bending load between the wheel bearing and spring perch. That is enough to easily exceed the yield strength of the axle tubes depending on how much safety factor Ford built into this car and COULD (not necessarily WILL, but COULD) lead to a tweaked axle tube.

One reason that this was common in the past with no problems is that the rear ends on older cars where a lot heavier and had thicker tubes with larger diameter tubes (which makes a HUGE difference in strength), so they had more than enough safety factor to carry the load without yielding. I don't know how many times I have jacked up my 81 pickup (with it's 9" rear end) by the pumpkin without thinking about it or worrying about.

Either way, it's your car and your decision.

PS: Why do folks keep posting diagrams of S95/97 cars and saying "here is the jack points for the s197..."??? Totally new car. Totally new chassis. Totally DIFFERENT jack points.

 

RRRoamer: That's a good point but the alternative is to use the axle tubes as jacking points as indicated by Ford's diagrams. This isn't just on the S197 but rather on the E-series, Crown Vic, and my T-bird. I'd rather use the thicker pumpkin as a jacking point, using only 1 jack in the process, versus relying on the axle tubes and 2 separate jacks. I do not have a vehicle lift at my house, so I make do with what I have. Again, we've been using the rear pumpkin as a jacking point for years without any axle tube leakage. If the tubes are thin or flimsy enough to leak from this task, I'd look into upgrading the axle tubes or the entire rear-end.

 

WHY?
Because if you look it up in the Ford books... That's all they show.
This is the 2007 delivery book, look at the dates.
Vehicle_Lift_Points__S7Z06A12[1].pdf

 

Ok. I'll restate... WHY does FORD keep showing a diagram of an s97 and calling it a s197??? I would hope they would know the difference...

 

It's probably the same reason why they showed a picture of a 1997 Town Car in my 2000 Crown Vic's owner manual.

 

So what procedure do you use to rotate tires?

Can you reliably get one side off the ground or does it need to be supported on all four corners?

 

When I jack the rear two wheels, I place the jack under the pumpking and as soon as it is up, I lower it onto jackstands. I just think it's safer for me and the car that way.

As far as rotating tires, I jack the car up one side at a time and place jack stand on the front and rear. When rotating radial tires you just need to rotate the front and rear tires so you don't have to do all four wheels at once, just one side at a time. That being said, I only rotate the tires in the spring (I average about 3500 miles/yr) and I jack up all 4 wheels at the same time. I take my time and use this opportunity to throroughly clean and polish the inside of the rims. Then I go onto the car and clean and polish the callipers and clean as much of the undercarrirage and wheel wells as I can reach with the wheels off.