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Suspension

Front End Alignment at Home

Friday, October 6th, 2017

Accurate front end alignment on any straight axle can be done in your home garage. Stop unnecessary tire wear and pulling side to side.

This basic blue-print shows it all. It’s a no-brainer! The two small notches on each end of the alignment plate are a suggested place to secure your measuring tape.

test

Low Cost Front Suspension Upgrade

Thursday, February 11th, 2010

The straight axle ½ ton GM pickups (1959 and older) were built tough! They served their purpose as the best in work vehicles for over 30 years. Other than an occasional kingpin replacement, they were almost ‘bullet proof’.

In today’s world, the reasons for owning an older truck, has generally changed. Most have been retired from work responsibilities and have become ‘fun trucks’ driven with care on smooth streets. Hauling merchandise is far down the list of their use.

The resulting demand for a smoother ride and better braking is the reason for many suspension options available from supply houses. For those willing to compromise on originality for an easier ride, one of the most proven and less expensive upgrades is the front suspension of the AMC Pacer. The price is right and the results are excellent. This coil spring rack and pinion front suspension assembly gives passenger steering and ride qualities.

A specialized adapter plate (available from the catalog on this web site, HP127) allows for the connection to your ½ ton truck. Instructions explain parts to remove from the Pacer assembly before the plate is welded in place. The total assembly is then bolted to the truck front cross member. No cutting on your truck! You can even trim the Pacer coil springs to get a lowered level on the total vehicle.

The adapter plate is not expensive. The main project is locating a good Pacer front suspension. This AMC vehicle was produced between 1975 and about 1982. The later years even had disc brakes.

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AMC Pacer (above)

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1947-1953 Advance Design (above)

Lever Action Shock Absorbers

Thursday, February 11th, 2010

Trucks of the early years were often exposed to the rough terrain of local gravel roads as well as the dirt ruts on the farm. Quality, long life shock absorbers were a necessity. Therefore, trucks from the mid 1930’s through 1949 continued with a proven design carried over from earlier vehicles.

The highly successful lever action shocks had been used since the 1930’s on GM cars and trucks. They should not be confused with knee action shocks on the front of mid 1930’s Chevrolet passenger cars. This is a totally different system.

Lever action shocks are simple in design but excellent in quality and long life. Their cast iron fist sized housing, bolted to the frame rail, contains hydraulic fluid and basic internal parts. The fluid is forced through a small internal orifice as the vehicle encounters uneven road surfaces. The slowness of the moving liquid inside the shock gives a cushion action that softens the ride.

The workmanship built into these lever action shocks are an excellent example of quality GM engineering. On many trucks throughout the country these factory shocks are continuing to serve after 50 years and with the abuse of no past servicing.

The weak point is the small rubber bushings at each end of the link, not the actual shock assembly. During many restorations the hydraulic fluid is changed, link bushings replaced, and the shock continues to operate like new.

Single action shock absorbers were standard equipment of the 1/2 ton and 3/4 ton trucks with an optional double action type available for more heavy duty requirements. A single action design has resistance only on the upward direction of the wheel while a double action style slows wheel movement on rough roads in both directions.

Basically the horizontal arm extending from the shock housing is attached to a vertical link that extends upward from the axle. The movement of the tire then causes this link and shock arm to also move, thus forcing of hydraulic fluid between chambers inside the shock housing giving a cushioning to road bumps.

In 1950, the lever action units were discontinued and replaced on new trucks with a modern tube type sheet metal shock. (This design continues to be used on today’s vehicles.) It should be strongly emphasized, the lever action shock absorber was not discontinued because it was inferior, but rather because the new style cost much less to produce and install. It was simply a matter of economics. The fact that lever action shocks had the potential to last 50 years over the 3 to 4 years of the modern unit did not prevent the change over!

lever action shock

Early Rear Axle Bumper

Thursday, February 11th, 2010

Mechanical components on trucks were usually kept for many years by GM. Unless an improvement was needed, there was no need to change a proven design.

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An excellent example of this is the rear ½ ton axle bumper. The design was used from 1929 through 1946 on Chevrolet and GMC ½ tons. A rubber bumper is held down on the rear axle housing by a metal cover with two ears. These ears are firmly secured by the two u-bolts that connect the leaf spring to the round axle housing. If the truck is overloaded or the shock absorbers are worn, the rubber bumper prevents metal to metal contact between the axle and frame rail.

Two of the attached photos show an original used retainer with bumper in place. The black bumper (now reproduced) is how the rubber part looks when new.

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early axle 3

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