Lowering Blocks

Revision as of 08:00, 12 February 2013; view current revision
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Blocks may be used for lowering leaf-spring cars like the Datsun 1200. This is the traditional easy, time-tested and inexpensive method. See Lowering for different methods.

Overview

Datsun 1200 use a straight axle mounted on top of the leaf springs, so by fitting blocks between it and the spring, the rear of the car is lowered.

Lowering

Block are available in different heights such a 1.5", 2" , 3" for differing amounts of lowering.

Slight lowering by using B210 isoclamp

NOTE: As with any lowering, the suspension travel becomes restricted compared to the factory ride height.

Plain block with screw in pins

custom-made blocks

Dimensions

click

 
Dimensions
width: 50mm
a: 12mm
b: ~15mm
c: 110mm
d: 8mm
e: 13mm

Ute needs wider bolts for larger axle housing

Datsun 1000 dimensions

Suspension Travel

• Trim the bump stop rubber by 1" to gain more travel
• Fit more compressible shocks
• Stiffen the effective spring constant to make bottoming out less likely, e.g. add leafs or add an overtravel leaf from a ute

Pinion Angle

Correct and Incorrect Angles

From top to bottom:
OK
 1 stock
 2 lowered with straight blocks
 3 angled diff. Transmission must be angled to match
 4 lowered with angled blocks
   NOTE: transmission must be angled to match
NOT OK
 5 only diff angled
 6 only gearbox angled

NOTE that lowering the car does not change the alignment angle. Although the driveshaft angle changes, the pinion-to-transmission angle does not change. Hence, no angle blocks are necessary.

stock alignment angle (black lines)

lowered - alignment angle does not change

Even if the lowering is done unevenly, the important angles do not change. lowered unevenly - alignment angle does not change

Notes

• Lowering blocks are legal in most countries, including most Australian states
• Square blocks will lift the diff squarely and will not change pinion angle
• Angle-ground blocks will change pinion angle so are NOT recommended. These are normally used with extreme lowering and require the diff angle to be modified or the transmission angle modified
• Handbrake cable will need to be re-adjusted after lowering
• On a BW68-equipped sedan, the blocks make for less access to the brake adjuster and brake bleeder. This is because the BW axle has in bottom-mounted brake cylinders

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