Basic lowering is something you will need to know.
The first thing a lot of people want to do when they get their car or truck is to lower it.
Basic lowering is one of the best ways to customize a hot rod. However, some guidelines need to be followed, as things can get unstable or dangerous real quick....
First, lets start with a few guidelines:
Figure out what you want to do first, then rebuild your front suspension. Don't waste a lot of work tearing stuff apart to lower something then having to rebuild the front end because it's still worn out. Figure out if you're going to use drop spindles, different springs, etc., then start tearing it apart and do it once.
Whenever you lower your suspension, get an alignment! You can pay a little now, or a lot later for new tires...
Also, the more radically you drop, the more complicated it becomes. A few inches usually doesn't bother anything. Three usually needs shorter shocks and may start to affect steering angles. Four inches needs new shocks, steering angle adjustments, possible brake hose issues, and may involve front suspension geometry issues. It goes on from there.
Don't get scared away though!
Basic lowering of a hot rod can be done safely and without too much trouble if done right...
Let's start with the front.
This is one of the most common spring setups for most front suspensions.
First! If you're going to remove coil springs, get the right tool. Most auto parts places will loan you the tool. Compress those springs before you ever undo the ball joints to take them out. There is a lot of compressed energy there and they can EXPLODE out of the car if not compressed first. Many people will run a chain down through them and the suspension before undoing the ball joints.
Many people will modify coil springs to lower their car. Never heat the coil spring to collapse them. This screws up the spring rate and can seriously affect the ride. This can make the car unstable or even dangerous. The same goes for cutting coils off with a torch.
If you want to cut a coil off to shorten the coil, cut it with a cut-off wheel or a sawzall. Start slow, cutting only a half of the coil off at a time. Then check it on the car as a little bit cut off will lower the car a lot.
However, you will be doing all this work and you still have a worn out coil spring that's been cut up. Instead of wasting all that work, just get a coil spring the right size in the first place. They're cheap. If you can't get an aftermarket one or have questions, get ahold of these guys:
The best way is usually to get dropped spindles. That way you still have full suspension travel.
Shorter coils put the suspension in the drooped range of travel lessening the travel. You will hit the bumpstops all the time and it may be hard to get it aligned.
Basic lowering of this type of suspension usually can't be done too much. However, you can usually get a few inches by simply adjusting the bars.
Often you can just adjust the bolts that limit where the bars are attached to the frame. Some will adjust at the crossmember, while some will adjust near the A-arm. Make sure you turn each bolt the exact same number of times to keep it level.
This again is like cutting coils. The problem is you usually end up on the bumpstops really quick. If you go more than a couple of inches, you basically bottom out the suspension.
Again, the best way is usually to get dropped spindles. That way you still have full suspension travel.
Straight axles are usually held in with parallel leaf springs or a transverse leaf spring.
The best, easiest, and safest way to lower them is with an aftermarket dropped axle or having yours dropped. This, in combination with lowering springs can make for quite a drop.
Some people will "flip" the axle. That is, if the axle is on the bottom of parallel springs, they will put it on the top of the spring.
While this will work, there are two areas that can get screwed up.
First, the steering linkage. the steering arm needs to stay in the same relation to the axle as it was before the axle was moved. Sometimes raising the steering box will take care of this.
Second, the axle is now very close to the oil pan or frame. Make sure the axle can move through it's complete travel without hitting something.
Ok, let's work on the rear.
First, you need to understand scrub lines. The scrub line is the imaginary line between the lowest spots on the wheel rims across from each other. No suspension parts or bolts can go below that line. Imagine you take the tires off the rims, put the rims back on the car and put the car back on the ground. No part of the car can go lower than the rims. This is so if you have a blowout, no suspension piece can dig into the ground and make you wreck.
There are really only two ways a rear end is held up: leaf springs or coil springs.
There are a variety of ways to lower a leaf spring rear end. Lowering blocks, new lowering springs, de-arched springs, flipping the axle, longer or shorter shackles, or relocating the spring anchor points.
Lowering blocks, while probably the cheapest way to go can also lead to bad handling. Especially acceleration and braking. Think bad wheelhop. Never go over a couple of inches.
It creates a lever between the axle and spring. Imagine a cement block on the ground. Now try to push it over. Not so easy. (Stable) Now put a couple of boxes of the same size as the block under it. Now try to push it over. Easy to do. (Not stable)
It's also easy to end up below the scrub line.
New lowering springs or de-arched springs are usually the way to go. Sometimes it can be very cheap as springs from other models of vehicles may work depending on your car. That's why it's so important to research your particular car on the internet. There's clubs that already have your particular questions answered. They already know the best and cheapest way to lower your car.
Flipping the axle can work if your vehicle has the axle under the spring. There are kits that make it easy to put it on top of the spring. Just watch for clearance between the axle and frame. You may have to "C" notch the frame. We'll cover that in another article.
You can also lower the rear by modifying the shackles. If your shackles hang below the spring, you might have room to lengthen them to lower the spring. If they are above the spring, you might have the room to shorten them to lower the spring. Don't get too carried away though as you are only affecting one end of the spring. This can lead to a change in the pinion angle of the rear end. While it probably won't change it much, it may be enough to cause driveline vibration.
Sometimes you can even raise the spring mounting points if you have the room under the floor.
Just remember: shock length, axle clearance, and tire clearance.
Shortening coil springs in the rear is much like front coil springs. Don't heat them or cut them with a torch. If you want to modify them, cut a coil or two off with a cut-off wheel or sawzall.
To go very far though you usually have to relocate the mounting points of the coil springs themselves. Then you may have to "C" notch the frame so the axle doesn't hit.
We'll dive deeper into basic lowering in following articles...
Return from Basic Lowering to Suspension
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