John 20:25

Among the annual rituals of adulthood (like taxes, and taking the dog to the vet), that I dearly dread is the annual safety inspection required by the Virginia State Police.

In theory, this is a wonderful idea: unsafe cars are identified, repaired, or kept off the road. Unfortunately, there are some flaws in the scheme: cars are only certifiably worthy for about 5 minutes (the time between one pays the fee and enters the vehicle, only to do some vile damage to its being). And, the inspections are carried out by mechanics for a $16 fee. Given that the hourly rate for a mechanic's time is in the range of $80-110 per hour around here, that's not exactly fair compensation for the amount of time it takes to do an inspection. To boot, a large portion of the population views their cars as mysterious appliances, so their is a huge temptation to find some problem, fail the vehicle, then offer a quote to fix the "issue".

Thus, it seems that whenever I get a vehicle inspected, someone attempts to fleece me.

The volvo was due for inspection in December. It has only been about 2000 miles since the last inspection. After a ~2 hour wait, I was called back into the shop, where the car was on the lift. A large group of mechanics eagerly pointed out that the control arm strut rod bushings were loose, and the ball joint boot was torn. "It's warn out!" one proclaimed. He jammed a bar in the suspension, to show flex. I argued that the ball joint didn't knock and that the control arms weren't going to fall off, being held in by freaking huge bolts. "No! It's very dangerous! You should have it fixed right away! The wheel could fall off!" the chorus intoned. I was handed a quote for $1200 to replace the control arms and ball joints along with a failing sticker.

I purchased the Volvo 740 for $400, approximately its worth on the scrap metal market, and put in significant effort to make it road worthy. Every expense is carefully weighed against the possibility of replacing it with a car that has not been driven around the planet 15 times. I got home, pulled out the shop manual, and started looking online for parts prices. The shops quote included two ball joints for $160 ($80 each), and two control arms at $410.78 ($205.39 each). Also was 6 hours of wrench time, billed in 10 minute increments ($630). With a quote like that, I felt doomed to a lot of time under the car, on the ground, outside in January. Fun times. Worse, that kind of parts cost was going to take a bite out of the budget.

Inspecting the manual, and backing it up with some googleing, the job appeared to be doable in the driveway. Discounting the lugnuts, each side is a 6 bolt job. There is one trick: seperating the balljoint from the control arm, which are held together by a conical stud in bimetal joint. (iron stud in an aluminum control arm). It looked like a 2 or 3 hour job at worse. I figured it might take an hour to beat the ball joint out of the control arm. (I would be very wrong on this point). The manual also noted that the maximum ball joint play allowable is 1/10 of an inch.

The price of the ball joints online (from rockauto and ipdusa) hovered in the 10-20$ range. Control arms, on the other hand, were almost impossible to find. I'd have to convert the whole front end suspension to use european cast iron control arms, which use different radius rods and anti-sway linkages. From the manual, it was pretty obvious that the bushing in the control arm were meant to be replaced, the control arm is a fixture, not a consumable. I took a quick glance under the car to survey the bushings. Only the ones on the end of the control arm strut rods were notably worn. They were also designed to be replaced without the aide of a hydraulic press. How much do those bushings cost? IPD: $3. I called the local autostore. They had a set for $24, and the ball joint for $10. I took the kaboodle, and ordered another set from IPD. To recap, I spent about $65 for parts to do the same job the shop quoted $570 for.


The strut rod bushing turned out to be as easy as I imagined. Remove the wheel, remove the bolt on the front of the strut rod, remove the bolt on the frame, smack the rod out with a mallet, replace the bushings, and rebolt. The bushings are surprisingly complex... there is an inner metal shaft the follows the strut arm, an outer metal shaft that follows the control arm, and a connical metal disc that matches the cone in the control arm. All three pieces are linked with rubber to provide a little flex. Over time, the link between the inner and outer shaft gets broken apart, and the increased play allows the other parts to get chewed apart by the control arm.

Volvo 740 control arm strut (also called "radius") rod.

How the bushings are situated in the control arm.

 New and worn bushings, control arm side.

Comparison between new and worn bushings.

Control arm strut rod bushings, outside. Not the breaks between the different metal disks on the worn bushing.

Control arm without strut rod installed.

Control arm with strut rod installed.

The ball joint proved to be a somewhat different story. I removed the tire, unbolted the lower control arm link, removed the bolt from ball joint stud, and gave the control arm some tentative pulls. It was totally stuck, and totally had less than 1/10 of an inch of play. I foolishly decided to press on, given that I now had all the parts to do the job laying around in shopping bags, and it was a warm sunny day in January. (The girly would later suggest that getting the car inspected elsewhere might have been a better, less laborious option.)

I pulled my shiney new pickle fork ("ball joint seperator") out of the tool bag, carefully placed it between the control arm and the ball joint, and smacked it in with my deadblow mallet. When it felt nice and firm, I leaned on it as hard as I could, only to feel it give and pop back out. A bad sign. I did that several more times, smacked the control arm several times, sprayed the whole thing with Buster Loose, and went inside to drink coffee and wonder what I had gotten myself into.

An hour later, reapplication of the mallet and the pickle bar showed no progress. I could jam it in harder, and then fit the jack handle over the pickle fork handle, but that only resulted in bending the pickle fork. Clearly, a different approach was needed. I found this article, and thus transpired to get my own gear puller. What a clean solution!

Hardly.

I installed the puller, and started working drive screw with the ratched. I felt the tension build, and eagerly awaited the pop and control arm sag that would happen when the ball joint gave way. At some point the ratchet wouldn't move anymore. I had to get a bigger wrench. A bad sign.

What was all that torque doing? Not moving the ball joint. Just deforming the stud.

Well, damn.

Clearly, I needed to put more force on it.

I put on my bad idea shorts and started dancing.

 I braced the control arm against the bottom of the with a nylon strap, then put the jack head against the ball joint stud. Certainly, 4 tonnes of force would push the stud out. Right?

Wrong.

 Although I could get the jack handle to bend pretty far.

I bought a torch and a bottle of mapp gas, heated the joint, and slugged it with the mallet more. No luck. I ultimately pulled out the control arm, and took it to my friendly neighborhood volvo shop.

Who removed it so easily that they did not even charge me for it!

I thought they would have used a hydraulic press, the marks on the side of the arm suggest a bench vice and a sledge hammer were at play. Kudos. I don't have those.

After two days of torment, I re-assembled the front end in about 20 minutes. I cleaned the inside of the control arm off with naval jelly, and applied a thin film of antisieze compound, on the off chance it has to be removed again in the future.



I'll take it back to get re-inspected this week.