Uh Oh – Broken Rear Shock Mount

Friday night, driving in the parking lot of an office park. Have them little speed bumps? Like 3” high and 3” wide. Going 15mph, bam-bam… next set: bam-bam… then again: bam-bam-grrrrr-rrrrr. Huh?

First thought, ah jeese, I’ve broken my exhaust pipe again. My previous repair was a sheet of stainless wrapped around the cracked and rotted exhaust pipe. Kinda sketchy. It is dark, I stop and check out underneath with a headlamp.

Drivers side.

Drivers side.

Uh-oh. There is a tube that connects the two frame rails, it goes between the rails right above the rear axle. The rear shocks connect to it… and one side has broken loose. Jeese. That’s not the sort of thing that I consider normal maintenance. I’m a little surprised because the rest of the frame looked so good but that tube always did have a sketchy look about it, looked like it had been rusted before, then treated.

Removing shocks so I can pull the shock tube loose.

Removing shocks so I can pull the shock tube loose.

Removing shocks

Removing shocks

Measuring distance so I have info for folks I call. Also to see what average shock length is in the rear.

Measuring distance so I have info for folks I call. Also to see what average shock length is in the rear.

Shock tube removed, with shocks.

Shock tube removed, with shocks.

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Can see the passenger side rear brake line passes very close to the shock tube. Could have been torn.

Can see the passenger side rear brake line passes very close to the shock tube. Could have been torn.

Another view of rear brake line.

Another view of rear brake line.

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Ok, well the good news is that it is just shocks, you don’t need them to drive. Broken springs would be another story. There is one part I don’t like, what is holding the frame of the truck together in the back? The body is bolted to it, probably strong but twisting might knock something else loose. I determine to drive safely home and leave it in the driveway until a repair can be devised.

Solicit advice from internet. Consensus: this is a common failure for old 60s because that area tends to rust. Also that the repair is the epitome of simplicity, just fab and weld in a new tube. Funny thing, doesn’t look like there is a lot of rust there but the tubing is very thin. I’m going to guess the failure is due to fatigue.

Anyway, I call around, I used to know folks that could make stuff like this, and they’ve all become old and highly paid so not interested in this type of work. I guess this is an excuse to give some business to TorFab up in Mukilteo. Of course taking the truck in may be an excuse for a bunch of while you’re in there.

This weekend I crawled under the truck, detached the stocks from the axle and then pulled the tube out. Very small amount of force needed to pull the cracked end clear from the frame.

Honestly the ride is much softer though it is clearly not well damped. Not the sort of ride I’d want for an autocross. Fun accelerating out of corners, it squats like a baja super truck.

I call Tor of TorFab up in Mukilteo. He says this is common, they’ve repaired it before. Probably cost between $500 and $600. Sheesh, that’s not so cheap. I figure I can find someone to do it cheaper. I take it by Ishii Motor Industries but they estimated $750. So it goes, I make an appointment with Torfab.

Repaired Tube. I hit it with Rustoleum to protect the por15 from any stray uv.

Repaired Tube. I hit it with Rustoleum to protect the por15 from any stray uv.

One concern, the remains of the shock mount pass through the frame. Perfect place for water and rust.

One concern, the remains of the shock mount pass through the frame. Perfect place for water and rust.

After a short drive in the rain the old tube is full of water.

After a short drive in the rain the old tube is full of water.

New repaired shock tube.

New repaired shock tube.

Before bringing it in a spend a few hours under the truck cleaning up the ragged pipes with an angle grinder. Boy the exhaust is sure rusted. I banged on it a few places and ended up with a big pile of rust on the floor, sucker is shedding its surface, looks like its really thin now. Dang, need to be replaced.

Picked up truck and Tor did a reasonable job. New pipe and welded plates are secure, all well painted with Por15, which is pretty expensive stuff. The shock pins are aligned well and the shocks went right on with a little grease on the pins, no issues so problem really is solved. I did see that the original pipe through the frame was intact and the inside of the pipe was not sealed where it met the plate. Once home I wire brushed that area clean, painted with several coats of vht suspension epoxy, then several coats of rustoleum cold galvanized zinc. I also hosed down all the new Por15’d metal with rustoleum. Still, that open tube through the frame is right next to the rear tires, it’ll fill up with water and road grit once it rains. Need a way to keep water out of there.

I take a quick drive after getting the shocks reinstalled and lubing all the grease nipples: wow, here I thought I was due for some new shocks, after driving without any shocks for 2 weeks I really appreciate the ones I have. I’ll be deferring the purchase of new shocks until there is a demonstrable need.

One short sighted thing: I should have had tor weld sway bar mounts onto the shock tube, now installing sway bars onto the rear will be a big production.

When picking up the car Tor noted that my exhaust was both on its last legs and rubbing against the read rubber brake line, melting it. The brake line needs to be replaced. But.. also.. the exhaust is not routed correctly, needs to run down the other side of the car. Previous owner routed the exhaust straight down from the engine and along the driveline. This means it sits too close to the transfer case which will cook the seals. Uh… shoot. How much is that? Tor says: oh, just go to “A1 Muffler Service”, just up the road, Wayne knows how it should be plumbed and he’ll do a good job for not much money. Cool!

I stop by A1 on the way home, meet wayne. He estimates $200 for new exhaust routed correctly. Sweet! In the 5 minutes I’m waiting to talk to him he is handing out some completed welding to a customer (some sort of flange), on his back cutting a muffler loose from a a car, giving keys to another customer. We wears a black ski jacket that has been absolutely thrashed on the back, strips of polyester and insulation hang loose from the back. His face is burned and heavily creased from all the welding. I determine that in all of north America this is one of the proud few that actually work for a living.