Raising all 4 Corners onto Jack Stands
I attempted to jack up the car by working on one corner at a time using a small hydraulic jack and then placing a stand underneath the chassis as a solid support. Well, I had the front raised in this manner when I lifted the first rear corner. The car then decided that it didn't like to be off the ground (shark out of water?) and started to slip off the front stands.... I immediately called for Superman to help stop the front end from crashing to the ground (the embarassment, the bill...) but it luckily stopped by itself in a slightly askew position and I was able to carefully lower the car to terra firma. Yes, I had put a wedge behind one back wheel before I started raising the car. So what is the correct procedure to get all four corners off the ground to remove the wheels? Also, what would be admissible support points on the chassis at the rear of the car? It is obviously not possible to place the stands under the same points used by the jack to raise the car in the first place and I couldn't see any other structure that I would trust to bear the weight of the car (at the front the structure a couple of inches inboard from the jack points seemd ok).
Good question. One of the local Prosche shops said that they jack the 928 up using a floor jack under
the rear cross member. In the front they use some plate near the center of the car as a jack point, with a wood block. I looked at this and there were lots of nuts in the way, but thats what they said they use?
I have not needed to have any work from them yet. I know the Posrche 928 books say to only use the jacking points.
The factory manuals do say to use the rear crossmember that supports the transmission as a jacking point. The process is to jack up right rear at the jack point, put jack stand under right front, lower jack. Do the same on the other side. Your car should now be 'up' in front. Then place the jack under the crossmember in the rear and lift. Place stands on both sides at the rear and lower car onto them. Works everytime. Get a nice 3 ton floor jack ($100) from Sears/Walmart/Parts America, etc. It'll make it go very smooth.
I have always used the rear suspension mounts right next to the jacking points as a place for either the jack or the stands then I just trust my jacks (with stands under the unibody rails not touching, just for emergency) to hold the front end. But I have several good jacks and it doesn't sound like you do. I recently asked Dave Roberts what he does. He said he uses the same points in the rear and for the front he places a large 2X4 on the unibody rail (I don't know if thats the correct terminology; I'm talking about the long frame looking pieces that run pretty much the length of the wheelbase). He uses the 2X4 to spread out the force and jacks it up this way then puts the stand under the jacking point.
I jack under the center of the rear cross member (under the transaxle) with a floor jack and a piece of wood. Then axle stands on the lifting pads in front of the rear wheels. In the front I use a small floor jack with a round pad on the cross member below the steering rack. A small chunk of wood will get you over the large dimpled hole in the center of the sheet metal pad. Never experienced any damage or disfigurement of the aforementioned parts. Seems stable all the way up and down. I go up about 18" total most of the time.
I got my '79 onto four jackstands by putting the floor jack cup under the big suspension components on the wheels, the parts that look like they hold the weight of the car when the wheels are on the ground, and they lift the wheel assemblies WITH the car, which makes for less reach of the floor jack to get the height I need... then I put the jackstands under the factory jack points to hold it. I found that its so well balanced that I actually removed a jackstand from the rear and it stayed up, and I could rock it diagonally back and forth a few inches with pressure from one finger. Unbelievable. Perhaps that is why the jack points are where they are. Balance. At no time did it ever wobble or threaten to go sideways off the jackstands. Anyway, its not so hard... I even used the floor jack under the transaxle with a woodblock, under the differential part, and it held up the rear while I took out BOTH jackstands and lowered down just fine, and there was no stress damage. These parts, after all, are suspended parts which hold the weight of the car on the springs/shocks anyway. Perhaps I took liberties, I dunno, and perhaps old Ferdinand would be spinning inhis grave... but I got the work done and it drives fine now. No worries.
In the rear, I use the flat plate next to the lift point pad. In the front I use the rear lower control arm support, unless I plan to remove the control arm. Then I place the stand under the forward part of the frame rail (with a 2x4) as Dave Roberts does. Just be sure to place it forward of the weld mark. That's the location of the crumple zone. Before it there is more reinforcement than aft.
The manuals are pretty specific in stating not to jack from anywhere except the jack points or the REAR crossmember. I believe in doing things the way that makes sense and I know that SOME of the factory's demands re: special tools, specific procedures, etc. are sometimes onerous and probably not entirely necessary. BUT, we are talking about the frame of a 3500+ lb auto. Not something you want to mess up. That said, I have found what I believe to be a simple and effective way to facilitate lifting while sticking by the factory requirements- Purchase three 1.5 to 2 ton floor jacks ( about $30 a peice at Sears, Pep-Boys, Auto-America, etc) place one each at the front jack points (preferably with wood pad in between) and the third at the rear cross member. Jack evenly (about 4 or 5 trips around the car) place jack stands at the rear jack points and lower the rear onto the stands for stability and place two stands somewhere in the front ( frame rails, front suspension) so in the unlikely event of hydraulic failure the person underneath ( ie, you) doesn't get crushed.
928 Tips Home Greg's Home