Tech Articles

Suspension

In August 1998, Shaun Wilkinson and I both replaced the rear springs on our 60s. We learned a few things the hard way, so I though maybe our experience could help others.

Parts

I had considered re-arching, but in retrospect it was good I didn't bother. My springs were sagged so much because the two main leaves on the driver's side had snapped and were rotting away, and the main leaf on the passenger's side had broken (the driver's side is the lower one in the photograph). Because I have spacers (see below) I couldn't see the damage until things were taken apart.

Instead we installed aftermarket direct replacements which we got through Parts for Trucks. Made by Triangle Auto Spring Company (DuBois PA, Fontana CA, Monterry Mexico), part number D87093 90-105, they are 6 leaf, just like the stock, complete with military wrap and tapered leaves. There is also a front spring available.

I also considered using poly bushings, but ended up using OEM rubber. People say poly is more durable, but then after 16½ years, my original bushings were in great shape. If I had gone to greaseable shackles and pins, I would have gone the poly route, but as it was, I didn't want to add more squeeking to my truck!

And finally, I added new rear shocks because mine were completely shot. You can't blame them though: the springs were in such bad shape that they really took a beating. My original front shocks are still fine (yes, after 300k km), so I went with OEM in the rear. Not only are they durable, but they are one of the few inexpensive parts for a Cruiser, less expensive then any aftermarket solution.

Spacers

The first thing that confused me is that 60s can have one of two setups in the rear: springs with or without spacers. Without is the standard setup on your average truck: springs held to the axle with u-bolts and spring seats. But with the spacers, you have a metal cover over the spring seat and within the u-bolts. Then there is a rubber "spacer" between the spring and the cover, and between the spring and spring seat.

I'm not sure what the spacer is for, but someone suggested it might be to distribute the stress on the u-bolts more evenly. Or perhaps it's to give a softer ride? In any case neither system is really any harder to deal with, but there are a couple things you should know.

First, the length of the u-bolts is different if you have spacers, and if you don't.

Second, the diameter of the hole for the centrebolt in the axle mount is also different. This is because with the spacer, the centrebolt fits into the metal cover which then fits into the axle mount. Without the spacer, the centrebolt goes straight into the axle mount.

My truck has the spacers, and so we had little problem with the centrebolt (we did have to remove a sleeve on it, so that it only protruded about 1cm). But on Shaun's, without the spacers, we had to grind down the head of the centrebolt to make it fit.

Removal tips

Do things the easy way: get a torch on those bolts and bushings. By heating the nuts red hot, they will come off infinitely easier. It not only goes faster, but it's unlikely you'll break anything (on the truck or you!).

Torching the bushings also makes the pins come out a lot easier. A few good wacks with the hammer (keep the nut on to protect the threads) should move the pin out enough to get a prybar in there, if you've torched them long enough. Burning softens the rubber, and once you can get some leverage, the pins will slide right out.

An oxy-acetylene torch will give you more heat than a simple propane.

Installation tips

This is the easy part. Generous use of anti-seize or silicone "grease" is a good idea.

But just in case you had a minor accident along the way and need to replace a pin or two, here's a suggestion. You can use a bolt and nut in it's place. A 9/16ths or 1/2 inch grade 5 bolt should do the trick. The only thing is, you'll need to grind larger holes on the shackle plate and hanger mount. It certainly gives a beefy look to the truck!

Results

Well, before I drove the truck, it was riding 10 cm higher. It's settled some since, but it's still riding about 7 cm over the sagged and broken springs. I haven't taken a spirit level to it yet, but I think it's raked forwards now, instead of back! It still appears to list to the driver's side though (well, it is a Cruiser).

The strangest result both Shaun and I experienced is that our steering wheels re-centred themselves. In both trucks, the steering wheels were at 10 and 4 o'clock before the job. With the new springs, they're almost bang on 9 and 3! My guess is that the worn or broken springs were causing the trucks to pull to one side, requiring a steering correction. No wonder my front tires are unevenly worn...

My truck now handles more easily. In fact, the handling is great, like driving a different truck! But my only base of comparison is the old broken springs, since that's how I got the truck.

In short, new rear springs, bushings and shocks have transformed the ride and handling. It's the best day's work (and money) I've spent on my Cruiser yet.