Torsion Bar

The Torsion Bar

The Xterra has a torsion bar suspension system. The bar twists and provides spring force for the front suspension. The forward end of the bar is bolted to the lower control arm, and at the end of the bar is an inward arm with an adjustment bolt connected to a bushing on a subframe above. The torsion bar is adjusted by the nuts on the adjustment bolt. When threaded in, the aft arm of the torsion bar is pulled up, twisting the bar, thus lowering the control arm (which raises the car). It’s a simple adjustment, as long as you have the right tools.

The left front of the Xterra is lower than the right. From under the car, I can see that the torsion bar is out of adjustment. Threading in the left torsion bar adjustment nuts would even it out. For the occasion, I go to Harbor Freight to pick up a pair of jack stands. The thing about Harbor Freight, if you don’t know, is that they sell super cheap tools. The aisles are filled with shiny new tools marked with ridiculously low prices. But beware, most of them are junk and have the potential of causing you harm. After much research online, I found enough evidence to believe that these jack stands won’t drop a car on me and I go through with the purchase.

Back at home, I cautiously jack up the left side with my compact 2-ton jack (also from Harbor Freight), and lower the car onto my new jack stands. I use both jack stands just to be sure. I give the car a gentle shake to confirm that it’s stable, and I crawl under the Xterra.

Torsion Bar

I locate the adjustment bolt/nut and grab a wrench. 17mm? Too small. 18? Still too small. Maybe it’s a 19. Digging through all the toolboxes in the garage, I fail to find a 19mm wrench. Of course this would happen to me. With a crescent wrench in one hand, and some other kind of adjustable wrench in the other, I start working on the adjustment nut. I turn the nut, one painful turn after another, being careful not to round the nut with my variable tools. Adjustable wrenches are nice and all, but they are bulky and awkwardly shaped and the smallest twitch would change the setting to be too big or too small. The adjustment is taking longer than it should, and I can’t for the life of me get a consistent measurement with my plastic Harbor Freight caliper (it was only 3 dollars!).

Torsion Bar

Finally, the adjustment bolt head is tucked into the subframe and no longer sticking down like it did before. I take my final measurements, and then I take my final final measurements, and decide that the left now matches the right. Excitedly, I jack the car off the jack stands and lower it back on its tires. I did it! The left side is noticeably taller than it was before and I’m done. Then my dad points out that the right is still higher than the left. I take some measurements using a stick, and he’s right. The right is still taller than the left. It’s better than what it was before, but still not the same. Sigh. I crawl back under the car to remeasure with my plastic Harbor Freight caliper and the measurement of the adjustment bolt protrusions are equal left and right (I think). It must be something else, it’s the tires. The right front has a newer tire than the other three corners of the car. It’s not only newer, it’s a different tire. If the front had a matching pair, it should sit level, or at least close to level. I think I need new tires (yes!) and I should probably stop going to Harbor Freight and buy proper tools instead.


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