What is Proper Use of Jackstands?

scottcarscottcar Member Posts: 8
I have and 87 Cadillac Sedan Deville that has a leaking rack and pinion. Dealer wants $560 to fix it so want to tackle the job myself. Since I will be spending a quite a bit of time under the car I want to be sure of the proper use of the jackstands. This car doesn't have a solid frame chassis like the older cars and am wondering if it is safe to put the jackstands in the same location that the tire jack goes? The location is just a thin piece of metal about 1/8 inch wide and the Haynes manual I purchased for the car calls it a rocker panel flange. Not much surface area to sit on the jackstands. The Haynes repair manual does have a section about jacking up the car, but it completely fails to mention the proper location or placement to put the jackstands. In fact it says the tire jack supplied with the vehicle should only be used for raising the vehicle when changing a tire or placing jackstands under the frame. Well if I am using the tire jack to raise the vehicle, it would be impossible for me to put a jackstand where the tire jack is so I assume that location is not the proper place. I could use it if I lift the car with a floor jack but the manual doesn't list the proper place to put a floor jack either. Thanks in advance for any help with this.


  • andre1969andre1969 Member Posts: 24,489
    I'm not sure about on the Caddies of that vintage, but on my Intrepid, I jack up the car by the front sub-frame. Even though the car is unitized, it still needs a sub-frame to support the engine, tranny, suspension, etc.

    What I do is position the floor jack under the lowest part of the subframe, which is also the beefiest, and just ahead of the engine. I have to be careful though, because it's real easy to catch the oil pan if I put the jack too far back. There's a level spot near the front wheels on the subframe where I then put the jack stands.

    I don't know if putting jack stands where the car jack would attach is a good idea. Doesn't seem like it would be too stable to me. Then again, what works for an Intrepid may not work for a Cadillac!
  • gasguzzgasguzz Member Posts: 214
    is definitely is not the place to locate a jackstand, it does not have enough load-bearing surface. I do exactly that on my oil changes, raise the corner on the carjack location with the floorjack but place the jackstand on the unibody-subframe. The best is putting it as close as possible on the subframe to where there is also a cross-subframe, you get the strongest load-bearing as that corner is structurally "boxed". Of course, it is imperative that you also have a jackstand with the appropriate rating and in good condition.
    Be safe.
  • mastermechanicmastermechanic Member Posts: 31
    On my Lumina APV (1993), I placed my stands on exactly the location of where the tire jack went. Think about it. When you change a tire, aren't you supporting the same weight at the jack point where you want to put the stands?

    On my vehicle, I had a tab that protruded from the body. The tab fit into the slot of the tire jack. That tab has got to be reinforced by some kind of structural design. On my vehicle, I placed the stands just on the inside of where the tab is. There is a pad there which will support the weight. When you go to a shop, notice where they place the lift mechanism.

    Another point. How are you going to change the rack without lowering the rear of the sub frame? I am assuming that you cannot change the rack without doing this. This means that you have to support the sub frame with some kind of floor jack.
    Remove the rear bolts and loosen the front bolts five to eight turns. You gonna have to determine if anything needs to be disconnected. I was fortunate because there is slack in the fuel lines, some in the brake lines, wiring harness, and in the exhaust pipe. I also used the floor jack in combination with the tire jack. You could always do this too. Use a two by six piece of lumber to support the body. Jack up the vehicle to the desired height. Place the stands on each side of the vehicle just behind the sub frame. Run the two by six from one jack stand to the other. I did this using cylinder blocks. It held for a month until I was ready to resume repairs.

    I placed the tire jack at the center of the rear most member of the sub frame. The slot in the jack fitted perfectly in the frame. Working between the floor and the tire jacks, I was able to lower the rack down enough to unbolt it and replace it with a new one. It would be to your benefit to have two or three people. One underneath watching and working the tire jack, one working the floor jack, and one checking to make sure nothing is being stretched or crunched against the firewall. The floor jack operator can also watch for clearances. The person underneath will work the tire jack that lowers the rear of the frame.
    Also disconnect the battery. You don't need any fireworks.
  • scottcarscottcar Member Posts: 8
    Thanks for the excellent reply Mastermechanic and great tips!

    >Another point. How are you going to change the
    >rack without lowering the rear of the sub frame?
    >I am assuming that you cannot change the rack
    >without doing this.

    Yes the manual says to remove the rear bolts, and loosen the front ones and then lower the subframe 3 inches but not more or damage will result. Because the subframe must be lowered, I knew I couldn't put the jackstands there. Manual also says to support the engine from above with a 3 bar engine support fixture (cherry picker?). Is that necessary as long as I don't lower the sub frame more than 3 inches?

    >Use a two by six piece of lumber to support the
    >body. Jack up the vehicle to the desired height.
    >Place the stands on each side of the vehicle
    >just behind the sub frame. Run the two by six
    >from one jack stand to the other

    Do you mean to support the body of the rack, body of the car, body of sub frame, or body of engine using the two by six? Could you go into a little more detail about that please.

    You seem very knowledgeable. Any suggestions on who to buy the rack from? Looking for reliability as well as price.

    Thanks again for taking the time to reply. I certainly appreciate it!
  • gasguzzgasguzz Member Posts: 214
    "aren't you supporting the same weight at the jack point where you want to put the stands" - fixing a flat LIFTS one corner, stands are intended to CARRY one side (or the entire car). Tire jacks serve a purpose, stands serve another.
    "I placed the stands just on the inside of where the tab is" - then the stand is not on the tab/flange itself but on the frame.
    "notice where they place the lift mechanism" - the lift is ONE system supporting ALL corners. A stand is an INDIVIDUAL system supporting ONE corner. If one corner fails, the rest may follow.
    Finally, there is a big difference - you are a "Mastermechanic", and know what you're doing.
    Be safe.
  • wtd44wtd44 Member Posts: 1,211
    Would you consider finding a good independent shop in your area to tackle the job at less cost than a Cadillac repair facility?
  • isellhondasisellhondas Issaquah WashingtonMember Posts: 20,350
    This is a DIRTY, FILTHY job even when the car is on a hoist.

    I've done a couple of dirty jobs lying on my back under a car myself. This will be no fun!
  • mastermechanicmastermechanic Member Posts: 31
    "Yes the manual says to remove the rear bolts, and loosen the front ones and then lower the sub-frame 3 inches but not more or damage will result. Because the sub-frame must be lowered, I knew I couldn't put the jack stands there. Manual also says to support the engine from above with a 3 bar engine support fixture (cherry picker?). Is that necessary as long as I don't lower the sub frame more than 3 inches?"

    ANS: I'm not sure, but if you use the bar, then the engine must be disconnected from the sub-frame. I couldn't see any reason why and I didn't use a bar or cherry picker. I actually lowered the whole frame with all of the bolts removed. The floor jack was on the main cross member by the oil pan.

    "Do you mean to support the body of the rack, body of the car, body of sub frame, or body of engine using the two by six? Could you go into a little more detail about that please"

    ANS: I supported the body itself. I had it high enough so that I could work under there. Then I lowered the sub-frame to change the rack. Don't be in a hurry after you set the two by six (or something stronger) to go underneath there. Shake the vehicle and even get into the cab of it to be sure that it will hold. I never fully got underneath it and was continuously prepared to get out of it started to fall. Be sure to block the rear wheels with some kind of block. Don't rely on the emergency brake, but use it too.

    "You seem very knowledgeable. Any suggestions on who to buy the rack from? Looking for reliability as well as price."

    ANS: Back when I would say TRW, but around here, that company has seemed to disappear with respect to automotive industry. On mine, I compared price, warranty and the brand name. If you plan on selling the vehicle, go with the cheappie, but if you are going to drive it, go with the warranty. I'm talking a warranty that comes from the manufacture and not the store or one that you have to purchase. If the store (Forest City) goes out of business, you are screwed.
    On all of my parts, I called ten places and listed them for comparison. I finally bought my rack from Advance Auto Parts. They were the cheapest with a warranty.
  • jgmilbergjgmilberg Member Posts: 872
    I don't think anyone should be putting their life into the "hands" of a 2 X 6!!! The car will come down with incredible speed making escape a very low probability. This may sound a little strange but have you thought of using a cherry picker to lift the car up by the bumper mounts? Remove the bumper, and bolt a chain to the mount, if you have the mounts that use energy absorbers(tube steel with a plate on the front) you need to remove those too. Once the chain is bolted securely to the body of the car hook up the picker and hoist away. In my opinion this is much safer that a 2 X 6, and you can still put stands under the car so if it was to fall the stands would catch the car rather that your head, chest or legs. You can use a floor jack to control the rate and level of the cradle decent to provide access to the rack.

    A job like this is really dirty and nasty. If you don't know what you are doing is it really worth your life to save $500?!!! Try asking the place that you got the quote from how much just for labor, if you got the part yourself and took it to them. You will be surprised, they really jack up the price on the parts.
  • mastermechanicmastermechanic Member Posts: 31
    That bumper shock is meant for forward impact not for vertical force.

    Like I said, anyone under a vehicle has to be continuously conscious of the dangers on being under a vehicle and be ready to get out of there at a moment's notice. $500 is definitely less than the value of a life. In short, if you don't know what you are doing, then don't do it.

  • wtd44wtd44 Member Posts: 1,211
    Hey, get your wife to go under the car. You tend the jack and watch the wood. If it cracks, you can at least try to warn her in time...
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    The suggestion of improvising some jacking system doesn't automatically make a person careless or crazy. The PROBLEM is that the way a thoughtful person might use 2X6 lumber to support a car might be VERY different from the way another person might use it....condition of the lumber, bracing brackets used, etc.

    My opinion is that by the time you make an innovation SAFE ENOUGH, you might as well go and buy some good jackstands.

    Some innovations can never be safe, like cinder blocks, etc, or blocks of wood that are not secured by a large base, lag bolts, etc.

    If a car can occasionally fall off a 4-arm lift, it sure as hell can fall off some contraption you slam together in your garage.

    I have seen cars slip off jury-rigged devices, and it has been my personal experience that fast or "slow" the failure is fast enough to trap just about everyone. It's very difficult when you are on your back with your arms and legs this way and that, to react to danger and scoot out from under a car.

    One danger is not being crushed, but being squeezed so tightly that you cannot breathe. And if you are working alone, well, you know the rest.
  • jgmilbergjgmilberg Member Posts: 872
    If you think that a car takes a moment to fall your wrong, in most cases you get no warning at all. Being ready to move out of the way
    might save your life, but not a limb, or even a finger. You won't be able to roll out, unless you are on a creeper, and if that is the case
    when you push off you are helping the car fall. The recommendation of using a 2 X 6 is absolutely absurd! I have a friend that is missing a leg from the knee down from doing something like that, I was there and saw it happen, all because he got it in his head a jack would hold the car. Well the car started to roll and before he could get all the way clear WHACK right on his leg. If I wasn't there to call 911 and jack the car up to get him free, he would have bled to death.

    That brings me to rule number 2, if you plan on doing work under a car NEVER do it by yourself, and for some reason you have to do work alone have a phone, cell or cordless with you and keep it handy in the event of an emergency.

    Mastermechanic - if you would have read the whole post you would have seen that I said to remove the bumper shock, and to bolt directly to the car body. In the new GM cars the bumper has a solid aluminium block that the bumper mounts to, not a shock. so if that is what is on the car you can bolt to that to lift the car up, but definitely NOT to the tube type energy absorbing bumper mounts.

    I have been working on cars for 15-20 years, and have never thought of using a piece of lumber as a jack stand. If my friend had listened to me and used jack stands, or at least blocked the wheels he would still have his leg! Please all the do it yourselfers out there do NOT use lumber to support a 2500 + pound car. Jack stands are $30 a pair for the small ones at Sears, a relatively cheap insurance policy when you consider your life, or lively hood is at stake.
  • isellhondasisellhondas Issaquah WashingtonMember Posts: 20,350
    But, some of the cheap, imported jack stands scare me too!
  • dpwestlakedpwestlake Member Posts: 207
    Not using jackstands is like not wearing a seat belt, using a grinder or welding without eye protection, running with scissors or not wearing a condom.

    you might be fine or you may be injured or killed. What's to debate?
  • moparmadmoparmad Member Posts: 197
    To prop open the door of my garage to let the paint fumes escape before I pass out from spraying my car without a respirator! Just kidding...Hey Mr. Shiftright I am going to write this down on my calender we finally agree on something. BE SAFE!!!
    I would call your local Cadillac dealer and I'll bet they will be happy to advise you,if they don't find another dealer. Worst thing you can do is try to guess,three scenarios,you put the jacks in the wrong spot and end up having to try and move them half way through the job,you put the stands in the wrong spot and end up breaking thousands of bucks worth of parts to save yourself $500 or so,or the worst scenario you end up in a very beautiful,albeit mighty flat pine box.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Gee mopar, you're not being an optimist about this are you? LOL!
  • moparmadmoparmad Member Posts: 197
    I prefer to call it being a realist...it is the mark of genius,or was that the mark of a fool...I can never keep those two straight.

    Have a happy day.
  • adc100adc100 Member Posts: 1,521
    we had a portion of our safety program devoted to preventing bad things from happening (jack falling). Moparmad has the general idea. The jist is that just before you take some action which would risk equipment or people (like a jack falling) you "stop" and then rethink your plan (its called "self-check". Another example is when you have done work in the engine compartment you "stop" and reevaluate what you did. For instance if you changed or checked fluids, you might want to physically "touch" each of the components you worked on to register what you might have forgotton. (perhaps you left the cap off of the P?S fluid container.) Another part is to have another person evaluate the action-for instance when jgmilberg had a concern about the car jack. All progressive industries have a program like this. Even after I retired I continue to do it. It works.
  • wtd44wtd44 Member Posts: 1,211
    I learned the value of the "check off" system during the Vietnam era, while attending to my duties in the south Pacific, Andersen AFB. B52 operations were characterized by multiple personalities checking and rechecking everything, and doing it from a manual-- EVERY time, not just now and then. Sure 'nuff it works. And like you, I apply today what I learned years ago.
  • wtd44wtd44 Member Posts: 1,211
    I can't agree with your categoric denouncement of KMart. They just may get their jackstands from the same suppliers that other retailers use. I have casually noted the extreme similarities between jackstands offered for sale by several outlets, and again very casually noted that in many cases, only the paint jobs on the stands gave any hint of differences among them.
  • jeproxjeprox Member Posts: 466
    i always use stands and jack as back-up. i jack up the car, place the stands - lower the car.
    then, jack it up to the point it just starts to lift the car and stop. jack will act as back-up in case stands fail!
  • dpwestlakedpwestlake Member Posts: 207
    What advantage is there in having someone with multiple personalities checking everything? ;-p
  • wtd44wtd44 Member Posts: 1,211
    Why are you calling me wtd44? I'm not at all like him. I won't tell you my name. You might use it for evidence...
  • dpwestlakedpwestlake Member Posts: 207
    you're just jealous because the voices are talking to me.
  • wtd44wtd44 Member Posts: 1,211
    you don't know jack (stand; proper use of).
  • seeligseelig Member Posts: 590
    this thread has become a joke.
    what's with the bickering guys?
  • wtd44wtd44 Member Posts: 1,211
    My remark #27 was meant to be a humorous play on words. I am aware that the printed word cannot convey "attitude" along with the message, so if I sounded like I was getting down on anyone, I sincerely apologize.
  • dpwestlakedpwestlake Member Posts: 207
    I thought this was all in fun, If anybody's feelings got hurt I apologize.
  • wtd44wtd44 Member Posts: 1,211
    Who woulda thunk that a little jackstand jesting was going to be perceived as heavy hitting?
This discussion has been closed.