Making wood blocks for raising the car
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difficulty: 1/5

Introduction

Disclaimer: these wood blocks are not a substitute for commercially available jack stands.  Wood blocks are for backup use in addition to jack stands and the information presented here is general information not specific to your vehicle!  Damage to you or other's property, injury, and death are possible consequences as a result of not supporting your vehicle properly and/or securely.  Since wood blocks can only help support the car on it's wheels, these are not a substitute for jack stands on the body of the car.  If you have any doubt about the safety of working on your car, follow all precautions as listed in the factory service manual and take it to a professional mechanic. (refer to the TOS for the full legal disclaimer)

A test measurement before assembly, this is how high the blocks will raise your car.  

Here is a picture of someone else's wood blocks, they raise the car about twice as high as the black rhino ramps pictured.

I normally use 4 jackstands or 2 jackstands and 2 car ramps to support the car.  The problem is that the jack stands can dig into the driveway unevenly and become imbalanced and scratch the undercarriage of the car.   Putting them on top of a secure piece of wood can help.  Never get under the car far enough to get injured if it's being supported by a hydraulic jack!  Many people have been killed when a hydraulic jack suddenly let go or slipped!  Never use cinder blocks as jack stands since they can suddenly crumble without warning.  Using wood blocks under the tires will give you more room under the car and spread out the weight over a larger surface, protecting the driveway and adding an additional safety factor to jack stands.  It can raise the car about 7-8 inches higher than the tallest setting on some jack stands.  It also has two levels so that you can raise all 4 wheels to the first level, then raise the car to the higher level or just use the first level by itself.

As long as you put the wood blocks on a hard stable surface that you would normally put jack stands on, such as level, solid asphalt or concrete, they will also be very strong.  Even at the weakest spot, in this example plan below, weight is spread out amongst 24 sq in. of wood, which could support the full weight of an SUV on only 1 block.  In theory, if you were to take away the side wood pieces and put all the weight on the center structure only, it would still be well within safe limits for compression since softwoods can take about 300 psi in the weak direction and thousands of psi in the strong direction.  Of course, a well engineered product would make this design as light as possible while still meeting your needs, but I wanted to overbuild it for piece of mind.  The biggest danger comes from the car tipping over, so customize the size of the wood blocks for your car, otherwise it could result in damage to property, injury, or death!  These plans are general plans for my car only and are not specific to your car.  Always inspect the wood for rot or damage before use.

After raising the car with a hydraulic floor jack by the jack points as specified in your factory service manual, put the first layer under all four tires.  Once it's raised, you can stack wood under the floor jack to raise it or use a high lift floor jack with a higher lift to fit the second layer under the tires.  Apply the parking brake and put the car in gear as appropriate.  Never get under the car while raising the car.  Hydraulic jacks could blow a seal and collapse, get tipped over or slip, or have the jacking point slip, so don't get under the car unless it is completely secure!

My personal jack is the costco 3 ton "arcan" aluminim jack.  Not every store may carry it.  It's about 58 lbs vs. 100 lbs for a comparable steel jack, has a lower padded bar to avoid scratching your car, is about $145 after everything, and has a range of 3.7-19.3" so it will fit under most lowered cars but lift high too.  It is not a racing "quick drop" jack so lowering it is safe and controlled, avoid racing jacks in general.  It also has a quick lift feature.  Craftsman jacks tend to leak and stop lifting after a while due to dirt clogging an internal valve.  They can be cleaned and rebuilt but I avoid craftsman jacks now due to their current design. 

The cost in materials was about $90 for 4, so if you just need to raise the front of the car a little bit for oil changes and such, a pair of rhino ramps or other commercially available ramps would be cheaper and faster since their average price is about $50-70.  However, rhino ramps only raise the car about 7 inches, these wood blocks will raise the car 14 inches or more.  This extra clearance is necessary when doing large jobs under the car such as dropping the transmission or subframe.  You can make just two for keeping the car level when changing the transmission fluid or differential in rear/all wheel drive cars.

Parts

Disclaimer:  These tips are generic guidelines only.  You must measure your car to see if a 24" long or 16" wide plank is stable enough for your vehicle.  Customize these plans to fit your car.

2x4 wood planks  (note that 2x4s are actually 1.5"x3.5", I don't know why, they just are)
    24" long 2x4 = 40 pieces
    16" long 2x4 = 44 pieces

2x16 wood plank, 24" long = 8 pieces

coarse deck screws, 3.5" long
coarse deck screws, 2" long
electric hand drill and various bits (preferred)

Yields 4 blocks 14" tall, 16" wide, and 24" long each.

Procedure

Many local hardware stores will cut the wood for free when you buy it, making it much easier to transport the wood and making for faster assembly.

Test stack the first block and mark it with a pencil.  The top layer's 2 pieces act as wheel chocks, you can leave these free moving or substitute 8 of the 16x2x4" wood pieces for wheel chocks.

Drill a pilot hole to help prevent the wood from splitting.  Use the deck screws to hold it together.  If you want to make it taller, make sure to increase the width of the blocks to make it more stable!

To use, secure the car and jack it up to fit the first layer under the wheels.  Apply parking brakes and wheel chocks.  Always make sure that the jack stands and wood blocks are on a hard secure surface.  When the car is secure, jack it up to the second level.  The reason why you want two levels is that you can use the lower level for smaller jobs and to keep the car somewhat level while raising it to the higher level.

The first 3 levels

The bottom layer complete with end chocks screwed in.  This is one piece for easy moving and storage.

The bottom 3 sections of the top layer

Top and bottom layers finished.  Note how the middle supports are lined up with each other.  You can put wheel chocks on the top layer to hold the wheel in place.  Total lift in this example is about 14", you can even put additional wood pieces below the bottom layer to act as a base and raise it even higher.  Always make sure the car is safe and secure, see the legal disclaimer and TOS agreement, etc.

They can lift higher than jack stands because they are lifting from the wheels instead of the frame.  In addition, they don't take up as much space under the car.  Below left is the first level, comparable in height to jack stands placed on the frame, below right is both levels (After taking the picture I applied wheel chocks).  This is high enough to drop the transmission on the pictured car and have some room to work under the car.

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