Rambler/Nash Rambler modern shock mount and control arm stiffener kit

03 apr 2021

new 08 jan 2021

The shock absorber on 1958 to 1963 Rambler Americans, and the Nash Ramblers it is based upon back to 1950, is unique to the car and not available from parts stores (though available from AMC parts sources; see below). Nearly every early American I see has a parts-store shock installed with a 1/2" diameter bolt through the lower arm retaining it. This is a disaster waiting to happen -- the lower shock mount is a critical suspension component that stiffens the lower arm. Without that stiffener installed braking, steeering and pothole forces bend the outer ends of the control arm, distort the holes that the trunnion caps thread into and ruin the lower arms. Usable control arms are becoming scarce. Out of the many I pack-ratted over the years upon close inspection only four were usable. Only one of those cars had the stiffeners installed.

Rambler original stiffener/spacer part

I have only one half of the stiffener/spacer set, but that is sufficient for measurements since two of these identical parts are used.

Overall length (both spacers) 1.50"
Flange width .1" approx
Flange diameter 1.00"
Bore .568"
Bolt Grade 8, 3", 9/16-NF
Nut Self-locking (swaged type)



My lower arm stiffener/spacer

Since the shock mount duty has been removed my new spacer can be much larger in diameter, and spread the forces involved over much larger arm area.

My replacement stiffener/spacer is 1.375" diameter, with a 5/8" hole. The original part was 3/4" diameter. Adequate, but also a compromise to allow it to be used as shock-eye mount. Mine's stiffer, spreads the load to more arm area. The photo below has the OEM part next to it for comparison.

You may have trouble installing the spacer if the factory-type spacer was not installed, as the likelihood of the mounting location being the correct width are probably slim.

Overall length 1.50"
Bore .62"
Bolt Grade 8, 3", 9/16-NF
Nut Plain nut (Loctite or stake)



Galvin's AMC Rambler Parts kit

Galvin's sells this kit, shown below, that replaces the spacer and bolt. Its overall length exceeds the original, but it's carefully made, and I will eventually contact them to ask.

You may have trouble installing the spacer if the factory-type spacer was not installed, as the likelihood of the mounting location being the correct width are probably slim.

Overall length (both spacers) 1.510"
Flange width .075" approx
Diameter .878"
Flange diameter 1.00"
Bore .568"
Bolt Grade 8, 3", 9/16-NF
Nut Self-locking (swaged type)

Installation

It should be obvious to you that any work you do on your car is your responsibility, no one elses, and certainly not mine. This is not advice, or a repair how-to. Automobile front suspensions are subtle, and this one more than most. If you think I am responsible for your results in any way, no matter how remote, stop now, this page does not apply to you.

This is an operation that must be done on the bench. This stiffener cannot be installed on-car, unless the gap between the two mounting flats between the arms is exactly correct, which is extremely unlikely if the spacer isn't now in there.

Please refer to the assembly sequence on the lower control arm page.

Modern shock mount

The lower shock mount is easy to install. You must have a stiffener/spacer installed. The factory system is fine, Galvin's replacement, or one you make.

The shock mount drops into place and is attached by two short 3/8-NC bolts, bolts inside, nuts outside. Tighten the two nuts (20 ft/lbs).

You may find it easier to install the shock by removing the lower bracket.

On my car I measure 14 inches between the shock mount holes with the suspension at full droop, and about 10.5 inches at full compression. The shock absorber should not limit travel in either direction. The OEM shock exceeds both, to no surprise.

Note also that shock absorber part extended and compressed measurements are from stud shoulder to stud shoulder (for fronts), and do not take into account the thickness of the rubber shock cushions. Each is about 1/2", increasing compression and extension numbers by one inch.

Shock absorber

I used Gabriel 81270 for years. The KG5514 part is monotube design, and is now my preferred part, or the slightly cheaper Excel-G 343137. The extended and collapsed measurements were taken from a PDF catalog or other online sources, except the original 3202200 whch I measured myself.

About shock absorber applications and part numbers

Parts for cars like ours aew not high volume items, and rather than manufacture and stock a wide variety of subtly different parts, the aftermarket likes to "collapse" similar parts into a single part in the catalog. A good example here are KG5514 and KG5517. Both claim application or fitment for the same car, and appear to share all specifications except the two length specs.

I used the KG5517 part before I knew of the KG5514 part. By strict measurement it seems possible to bottom the shock but in practice the spring is never zero height. This seems to be a clear decision to collapse the catalog, maybe after stock or orders for one part slows sufficiently, it will be superceded by the other. Luckily here there is sufficient choice, and likely others, I stopped looking. Other parts, like suspension bushings, we're not so lucky, where catalogs list parts that simply do not fit and do not work.

Also I specifically sought out shock absorbers from cars lighter than the American. Modern cars have stiffer suspensions and seem to have stiffer shocks, and my early experiments using shocks from what I thought were comparible cars (by weight) were not good -- too-stiff shocks transmit road impulses (potholes, etc) right into the chassis and the seat of your pants. These older cars are softly sprung, with longer suspension travel for older, worse roadways. Shock absorbers exist to dampen spring oscillations, and a stiffer shock does not improve anything.

Location Part Type Application Extended Compressed top/bottom
Front AMC 320 2200 ? 58 to 63 American 15.25 10 stud/Nash eye
Front KYB Gas-A-Just KG5514 mono 1961..1968 Volvo P1800 rear 13.9 8.75 stud/stud
front KYB Excel-G 343137 twin 1971..1980 Pinto 14.25 8.75 stud/stud
Front Gabriel 81270 twin 1964 Volvo 122 rear 17.7 10.6 stud/stud
Front KYB Excel-G 343219 twin 1961..1968 Volvo P1800 rear 17.4 10.3 stud/stud
Front KYB Gas-A-Just KG5517 mono 1961..1968 Volvo P1800 rear 17.8 10.9 stud/stud
Rear Gabriel 81440 twin 1982 Toyota Starlet rear 24.6 14.59 stud/eye

Installation photos

Here's one installed on the passenger side of my '61 Rambler Roadster.






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