Heatwave

I intend to replace brake rotors and pads in the near future. I will use a hydraulic floor jack positioned under the jacking points to lift one corner at a time.

My question is: when a corner of the car is jacked up, where should a jackstand be positioned as a safety device?

This question applies to all four corners.

carguyshu

the jackstand should be where the jack point is. its a pain.

also be sure you have disabled SBC before doing any works on the brakes. To properly bleed the system you will need both STAR and a motive bleeder pump. dot4+ fluid should be replaced every 2 years as it is more likely to absorb moisture.

Heatwave

There was a post ... somewhere recently ... mentioning the use of large bolts inserted in the jackstand holes ... place the hydraulic jack under the end of the bolt and jack it up. Does anyone know what size bolts are needed for this evolution?

kbob999

For jackstands - I use the front inboard suspension arm mount points of the front subframe (inboard aluminum casting), and the rear subframe mount bolting locations (forward pair).

If you think about load transfer points, i.e. how the loads transfer from the wheels to the frame, you can understand that these locations are pretty strong, and can support the weight of the car. Works for me.

LGAFF

I jack up the back by differential and then put bolts in the factory jack holes and rest them on jack stands

Heatwave

LGAFF: what size bolts do you use?

LGAFF

3/4" by 8" Grade 8, I always secure them to the jackstand

Rudeney

The easiest way to lift the car is to use a low-profile jack on the center points. The front center jack point is a square plastic puck, protruding from the middle of bottom engine cover. It's best to raise the body with ABC first so your jack clears the bumper. The rear center jack point is just to lift under the differential housing. I lift the front first, then place jack stands under the front side pucks, then lift the rear and place jack stands on the rear side pucks. I can have the car on four jack stands in about 10 minutes. I don't use any bolts - my jack stands have a saddle shape that mates quite well with the plastic pucks.

Heatwave

My jack stands appear similar to yours, Rodney. Thanks for the instructions.

Heatwave

Lgaff: what do you mean by your statement, "I always secure them to the jackstand."? How do you secure the bolts to the jackstand? Or am I overanalyzing your post? Happens.

LGAFF

I have some Gorilla Tape wrapped on the back side of the jackstand......it just ensures the bolt cant slide backwards off the stand......probably alittle overboard but better safe that sorry.....I like the bolts better because there is no chance it could slide off the puck.

That being said the Rocker structure is pretty robust if the bellypan cover is off.....you could probably jack it up in the center with no issues......but I haven't done it. Saw someone do it on car they were stripping, they had no issues.

Rudeney

I assume when you talk about using bolts, you are inserting them into the frame in the threaded receivers, behind the plastic covers on the rocker panels, where the emergency jack attaches? I guess that would work, but you are then relying on the strength of these bolts to support the car. I prefer to place my stands underneath the frame on those plastic jack buffers. They are made to support the weight of the vehicle.

LGAFF

To each their own....that bolt is going nowhere, the factory jack insert is a tube of the same size. I always leave other safety devices in place also....jack or extra stands. Sometime the hockey pucks break of give, so I use the bolts....when I say break of give that's during setup not...if they are under load they are fine


Min Tensile Strength for a 3/4 Grade 8 bolt is 50,100lbs

Heatwave

Another source reports that tensile strength for Grade 8 bolts is 150,000 psi ... shear strength is 90,000 psi. I think we're safe.

Source: Portland Bolt & Mfg. Co., Calculating Grade 8 Shear Strength.

Rudeney

Sounds like the bolts are strong enough, but I just feel better with the weight of the car directly on top of the jack stands. Really what I need is a two-post hydraulic lift.

alk247

I use so called scissor lift. The advantage is that no drilling of concrete is required. Disadvantage - lift frame is in the way sometimes.

Rudeney

Yeah, I've seen those, too. They are nice and cost-effective, especially for small garages (like mine!). What I probably need is a portable two-post unit like this:

https://www.maxjaxusa.com/buy-purcha...d-package.html

It does require drilling into the garage floor, but that's no big deal as it's not left permanently in place.

kaigoss

Why so complicated? - Use the factory jack to lift up each side, slide the jack stands underneath the pucks, done.

Leej

@Rudeney I'm wanting to put all for corners on jack stands and had a question. Do you put anything between the floor jack and the rear differential housing (I have seem some say use a piece of 2x4 or rubber piece etc)? Also, do you put anything between the side pucks and the jack stand saddles?

I have seen the Reverse Logic cups that fit under the pucks, but I don't think these would sit in the jack stand saddle. Although they would be useful for other types of lifts (protecting side skirts, etc.), but I'm not sure of the value?

Just curious.

Thanks

Lee
2008 SL550

Rudeney

My floor jack has a rubber pad in it, so I don't use anything between it and the differential. The saddle shape of my jack stands fit nicely into the shape of the corner pucks.