The links are listed as 28.8 foot-pounds.
When replacing the strut assemblies, or when taking them apart to replace just the strut, forget about marking the cam bolts. Doing so will get you somewhat close, but there's still a better way. For this to work, the vehicle must be supported solidly on jack stands under the frame or front cross member so it won't rock. Lock the steering wheel so the steering linkage won't move. With only one wheel removed, reinstall two or three lug nuts, with washers for spacers if necessary, to hold the brake rotor in place. Use a carpenter's angle finder with a magnetic base attached to the rotor. Either set that tool to "0", or simply remember the angle shown. The goal is to set camber back to that value later.
Next, if you loosen the two lower strut mounting bolts a little, you'll see that if you push and pull on the bottom of the strut, there is a lot of play between the head of the cam bolt and the pocket it sits in. With old mechanical alignment equipment from the '60s, we were happy to be able to set camber to within 1/8 degree of specs. Today, with computerized equipment, we can set it to within.01 degree accuracy. When you can move the strut in and out by hand, you're changing camber a good one to two degrees without rotating that cam bolt. That proves that no matter how carefully you mark the bolt head, there's very little chance you'll be close to specs when you're done.
I'm happy you'll have new coil springs, but those don't become a factor right now. The new strut, just like the old one, will be fully extended with its length limited by the strut itself, not the spring. Once the new assembly is in place, us the cam bolt to bring the rotor back to the angle you found at the start of my wondrous procedure, but here's another tip. Start with the rotor tipped in on top a little from where you want to end up, then snug the bolts just enough that you need some force to move the strut. Use the cam bolt to bring the top of the rotor back out to the angle you started with. Tighten the bolts when you reach that point. If you go too far, don't simply turn the bolt to bring it back down. Instead, repeat the step by running the rotor too far in on top, then bring it back out to the desired angle. Even if you don't follow this step exactly, the alignment specialist will likely do it too.
The reason for doing it this way is when the cam bolt is tightened in the final step, the head of the bolt will be holding pressure on the pocket on the strut, so if you hit a huge pot hole or bump, the strut can not shift or slip. Due to the play between the pocket and bolt head, the only way it could slip is for the rotor to move out on top, and the only force trying to do that is gravity and only when the wheel is off the ground, which hopefully won't be too often.
Here's a couple more hints. Observe the orientation of the steering wheel on a straight road before you start the strut replacement. We'll assume it is perfectly straight for this story. You won't be tested on this overly complicated explanation. You only need to understand the final results. If you look from the left side of the vehicle toward the wheel, and use your x-ray vision, you'll see the lower ball joint, and the two lower strut bolts roughly ten inches above it. Somewhere right in between them is the steering arm usually cast as part of the steering knuckle. That's where the outer tie rod end is attached. Outer tie rod ends are threaded onto the inner tie rod ends. Those are the adjustments to set each front wheel straight ahead when the steering wheel is perfectly straight. Setting that "toe" is the last step in any alignment. As little as a quarter turn on that threaded connection can send toe from perfect to far out of specs, so it's easy to see how precisely that must be adjusted.
To continue this story, when you use the cam bolt to move camber, (the brake rotor and angle gauge), in and out, you're also moving the steering arm in and out a proportional amount. Later on, toe has to be readjusted to accommodate that. For right now, as you move camber in and out, you'll see the rotor also turns left and right at the same time. You're changing toe on that wheel, but for tire wear and steering wheel position, we always have to look at the "total toe", meaning toe on both wheels together. Say, for example, you position camber so it causes the left wheel to be turned too far to the right. Many people incorrectly think that tire will scrub on the road surface and be the only one that wears badly. In fact, regardless if toe is wrong on one or both wheels, you have to bring them back to exactly equal to make the vehicle go straight, and you do that by turning the steering wheel. To say that a less complicated way, if toe on the left wheel is misadjusted so it's steering to the right, you have to turn the steering wheel to the left to make the vehicle go straight. Both front tires will scrub and wear equally. That type of tire wear always affects both tires equally.
I'm finally getting to the exciting point of the story. By replacing just one strut at this time, if you get camber back very close to where it was when you started, the orientation of the steering knuckle will be the same, and on a test drive, the steering wheel will be straight. You can also use that observation to make slight tweaks in camber until you get the straight steering wheel. Those threads on the tie rod ends have a very fine pitch. A quarter turn on that adjustment is enough to show up as a slightly off-center steering wheel, so you can see how precisely they have to be set. To get the same amount of change in the steering wheel by adjusting camber, the amount of movement with the cam bolt would be way too small to see by eye. If you do get the straight steering wheel, you'll know you have camber set very close to where it was when you started.
There's a little play between the three upper bolts and their mating holes in the inner fender. Most often that play is too small to be able to be seen in the reading on the angle finder. I like to loosen those nuts, then slide the mount in as far as possible. It just takes a small flat-blade screwdriver to do that. You'll see "witness marks" in the dust around those holes to know how much you moved that upper mount. This step is not terribly high in importance because there's no guarantee the locations of the bolts in the new upper mount are the same, but it can lead to a little more accuracy. This step has more value when the old upper mounts are being reused. I like to place the new mount the same way, with the bolts all the way in toward the center of the vehicle. That way, later when I'm adjusting camber, if I just can't get that little extra movement I want, I know there's a little movement available by prying the upper mount out. That can provide as much as a tenth of a degree when I want to be really precise.
It's okay to place a very light coating of grease on the threads of the lower strut bolts, but nowhere else. The contact points between the strut and steering knuckle need to be dry to achieve the best clamping action so camber won't shift. Absolutely do not use anti-seize compound anywhere in this area, including lug nut studs. Additionally, most import vehicles have wheel studs that have a silver, light yellow, or light blue anodized coating. That coating is a lubricant. It will dissolve in the presence of grease or oil and lead to peeling the threads off the studs and nuts. The next person to try to remove those nuts will unfairly get the blame for the damage.
Once you've test-driven the vehicle and you have a reasonably straight steering wheel, tighten the two lower strut bolts as much as possible with a hand ratchet or breaker bar. Don't concern yourself with torque specs as they have no validity here. During the alignment procedure, camber is always the first angle to be set because changes in camber cause huge changes in toe, but not the other way around. I have to defer at this point to my years as the alignment specialist at a very nice Chrysler dealership. The strut setup is identical on most of their front-wheel-drive vehicles. The tool setup consisted of a 22mm flex socket, 12" extension, and a flex-head ratchet with a really long handle. Hold the ratchet in one hand, then with the other, reach over the top of the tire to place the socket on the nuts. It was almost impossible to loosen those nuts with a standard ratchet. Next, move the tools to the other side of the strut and rotate the cam bolt to set camber. As I mentioned before, the final adjustment should move the top of the wheel / tire outward so the cam bolt's head is keeping pressure on the strut. That prevents the adjustment from slipping. Now go back to the first side and tighten the two nuts. The reason for describing this is to point out there is no way to tighten those nuts with a beam-type torque wrench. You could try to use a click-type, but the flex socket affects the accuracy. That's why there's little validity to using a torque wrench for these nuts. With the long-handled ratchet, it's very easy to achieve sufficient tightness on those bolts. I've never known anyone to try to use a torque wrench on them.
Even if you are able to end up with a perfectly straight steering wheel, the vehicle must still be aligned. The angle gauge trick on the brake rotor is less accurate than the old mechanical alignment equipment. Those could get to within roughly 1/8th degree of accuracy. That was sufficient for old, heavy rear-wheel-drive cars of that era. Today, computerized equipment can be set to read to.01 degree of accuracy, and that is needed for today's lightweight cars. Besides being a major tire wear angle, camber causes a tire to want to roll, or pull, in the direction it's leaning. Camber on each wheel must be in specs for best tire wear, and it must be equal on both sides so their pulls will offset each other. Then, we want camber to be a little higher on the left wheel to create a slight pull to offset "road crown". That's the slant of the road surface so water runs off.
A hint for reading tire wear patterns. Camber always only affects that one tire. Too much positive camber, leaning out on top, causes accelerated wear on the outer edge of the tread. Too much negative camber, (leaning in on top), causes wear on the inner edge. Total toe always affects both tires equally on the front or on the rear. If individual toe is off on just one wheel, the steering wheel will be off center. It's possible for individual toe to be off an equal amount of both wheels. The steering wheel can appear to be straight, but there will be a choppy, or "featheredge" pattern on both tires. If it's bad enough, you can see it. For less severe toe wear, run your fingertips across or around the tread. One way will feel fairly smooth, but the other way you'll feel your fingertips catch on the raised edges of the blocks of rubber. That's a fast way of telling if you should recommend an alignment.
Reading tire wear gets more complicated when both camber and total toe are out of specs. Besides looking at wear patterns, too much total toe out, meaning both wheels are steering away from the center of the vehicle, will cause an exaggerated response to cross winds. If the wind, for example, blows from left to right, it pushes more of the vehicle's weight over to the right tire. Since that one is steering too much to the right, with more weight on it, the vehicle wants to follow that tire. Now you have a tire steering to the right and the wind blowing to the right. The left tire will do most of the scrubbing, or sliding to the side a little. That kind of handling problem, along with pulling to one side and an off-center steering wheel can all be observed at any time. Only tire wear takes a long time to show up.
Finally, once you're satisfied with the strut installation, repeat the procedure on the other side. When you do both struts at the same time, there is no way to know if one or both are set to specs or are off by a lot. Doesn't matter when the vehicle is going across the shop over to the alignment rack. These tricks are mainly for when you need to drive it there.
Please keep me updated on your progress.
Wednesday, December 11th, 2024 AT 2:50 PM
