My friend needs help changing the brake pads on his 2010 Mazda RX-8 so we’ll need to jack it in the air. To support the car on jack stands, various sites seem to agree that you should use the reinforced area around the four jack points described in the owner’s manual. These jack points are at designated points right over the pinch weld on the unibody between the wheels.
The emergency scissor jack included with the car is typical and looks basically like the one below. It allows the pinch weld to slid into the opening allows the jack to contact the unibody inside and outside the seam.
If I put the jack stands right under the pinch weld, the car’s weight will be on the pinch weld rather than the reinforced area above it. I suspect this will just crush the pinch weld. This has apparently happened to several people.
One bad alternative is to use wood blocks or hockey pucks to create a form to go over the jack stands. This seems like a terrible idea since the wood or plastic is liable to split and because the blocks might slip off the jack stands. This seems much less stable than if it just had the jack stand alone. I’m not interested in solutions like this.
The other alternative is to place the jack stands fully inside the pinch weld at the reinforced point, with the jack stand tops parallel with the pinch weld. I think the jack stands would be fully under the reinforced area around the seam weld. This makes the most sense to me. I’m concerned, however, that by putting the jack stands solely inside the seam weld, I might be concentrating too much weight on the inside of this reinforced area rather than distributing it across the seam weld as the factory emergency jack does. Is there a better way to support this car on jack stands? Am I worried about nothing?
In my experience, I’ve jacked a car (using a floor jack, not a roadside scissors jack) at the midpoint of an underbody crossmember and put jackstands at the outer edges of the suspension at each corner. If you’re doing brake work, you don’t need (or want) the suspension free. The Chilton’s et al guide I have for any car I’m doing my own maintenance usually photographically documents where those lift and stand points are.
That said, I’m seeing more current jackstands which have saddles shaped to work with the unibody pinch weld jack points, so that’s an option if you buy a recently-enough manufactured set.
Thanks gnoitall. I will use a floor jack under the central jack points to get the car in the air. The question is really about how I keep it there. I don’t like the idea of using the suspension. No manual seems to support that and several suggest that it’s less stable and more likely to damage the suspension. I’ve never jack up a car by the suspension, though I have used a solid rear axle on an old full-frame car.
I looked for new jack stands but I can find only one pair find any with saddles that form fit over the pinch weld (here: http://www.jackpointjackstands.com/Home_It_Works.html). Those jack stands don’t seem to be available from the site they link to anymore , it seems to require a new jack, and I have no idea how much the jack or jack stands cost. There’s a limit to how much I want to invest in new tools to help my friend.
It also seems like I should be able to use regular jack stands. I doubt every shade-tree mechanic jacking up unibody cars uses these obscure jack stands I’ve never seen before.
I use hockey pucks. I jack with a floorjack on the jackpoints and don’t worry about it fitting exact, although you can finagle any part to fit that slot spot on.
I manage to get jackstands in by jacking on a suspension component point (differs by car) which frees up the jackpoint on the unibody.
At each corner of the car is a suspension mount point that carries the weight of the car at that given corner… so jacking from it ensures you have a point that can carry the load.
From Amercian muscle to exotic German and Italian brands, this has been my course of action.
I have a car with a carbon fiber tub, and it’s the only time I’ve doubted myself and changed technique.
I wanted to add: Consider jacking at the jackpoints, but using jackstands elsewhere. Or even consider not jacking or not using jackstands at the jackpoints.
This is a good question and I never thought about that. I have routinely used the pinch welds with a normal jack and jack-stand for quite some time. There are also other structural members under the car that can also be used, just not the sub-frame, or the sheet metal of the floor pan.
You might to check if you have a scissor jack that also has the slot for the pinch weld and then you can have one side of the car up. And have the jack-stands as safety.
Thanks Philster. I know where the central jacking points are for the floor jack. I want to know how to support the car on jack stands once I’ve raised it. I’m reluctant to use jack stands on the suspension. I think you meant to link to a video but it didn’t come through. Could you please link to it again?
Thanks electronbee. On my own cars, I’ve occasionally used the pinch welds as you have. At least one of my beater cars had a crushed pinch weld. I don’t remember if I crushed it or if someone beat me to it. My friend’s car is in perfect condition though and somewhat rare. I don’t want to hurt it.
I don’t want to work under a car supported only by scissor jacks. Someone in the next city over was killed a month or two ago when his scissor jack collapsed as he worked under the car. Using two jacks doubles the odds of that kind of failure.
Perhaps as you suggest, we could use the scissor jacks to raise and hold the car and then put jack stands close by under the jack points as a backup. That seems cludgy though.
When I work on my RX7 I use the control arms to place the stands. In the front I have to Jack up each side independently using the recommended jacking points with my floor jack. For the rear I use the rear diff pumpkin to Jack with.
I work on cars professionally and often use suspension components as a place for the floor jack and/or the jack stands. The weight of the car is borne by these when the car is on the road; they can safely support the car when it’s on jack stands.
Which supports the body through the suspension.
Wow. That seems way too overengineered, fussy, and precious. Perhaps it’s a blessing you haven’t found a way to buy them.
You have to get over your hesitancy to use jackstands on the suspension. If you can’t, then use other suggested jacking locations and use the jackstands on the jackpoints.
I jack up and jack stand on the control arms for brake work. It’s a lot easier than putting the jack all the way under to hit the a frame point and then need to jack it up twice as much, just need the tire off the ground not the entire truck a mile off the ground.
I could see with some cars wanting to jack up on the body just to put it at a better working height but it’s entirely unnecessary. If you do work in your own driveway it’s kinda expected to be inconvenient.
Those are “Series II” RX-8s, so they should be the same as my friend’s car. Thanks for posting. I will probably use the reinforced body points noted there. There seemed to be so many bad recommendations in those threads that I ignored what seems to be the best posts.
I sincerely appreciate your professional perspective. Some people are saying that the control arms can be bent when you use them to support the car. I’d like to avoid that if at all possible. The control arms are strong but I think their strength is mostly in compression. The issue for me is whether they have sufficiently strong bending strength if it put the support on them from below. That said, I might just use the anchor for the lower control arms if it fits neatly into the jack stand.
And I agree with you about the “fussy” jack stands I linked to. I would appreciate a jack stand that went around the pinch weld but that set seems unnecessarily complicated.
I like the extra height and using a documented jacking point. I don’t mind pumping the floor jack handle a few more times to get it. Plus, this is a low-to-the-ground RX-8. My jack will hit the central jack points in the front and back after approximately two pumps. There’s not a lot of work to get there.
This may not matter in this case but I had a tin can 90s Celica in a shop up on a 4 point lift and the doors wouldn’t open while it was up there. Either the weight of the center was compressing the doors or the two ends were under tension pulling them tight.
