How to Use a Torque Wrench for Automotive Maintenance
Oct 4, 2019
Without a doubt in mind, we can say that automotive maintenance is one of the areas where the torque wrench finds a lot of use. This is a good thing too, because a vehicle's engine, suspension parts as well as other body parts have many tension parts.
When the need for fastening arises, you need to do it to the manufacturer-recommended torque level for your vehicle to operate well. However, what parts of the car can you use a torque wrench on? Keep reading to find out.
Torquing Bolts to Specified Tension Levels
Manufacturing a car is a very precise business and so is the repair of the same. Thus, most of the tension parts in a car, right from the wheel lugs to the sequence bolts in the delicate engine parts require fastening to the right amount of torque.
If this is not done, two scenarios can happen. But, you have to choose the right wrench for the right job. So, you can have a look at this top quality torque wrench reviews and choose your desired wrench for the right job.
You Might Under Torque Bolts
They will work themselves loose and not only cause irreparable damage, but can also put you in danger. Assume that you under-torque wheel lugs and they come off while speeding on the highway. This can be dangerous to you and others.
You Might Over Torque Bolts
This will most likely lead to costly damage. First, you will lose the bolt because when it slips (threads do not hold), it becomes useless. You will most likely have to buy new ones. The tension part that you are fastening may crack because over-torquing means applying too much pressure.
Now that we know why it is important to use a torque wrench in automotive repair jobs, how will you use it? Like any other tool used in any industry, there is a process to follow to ensure you get the best service from the tool. Thus, just knowing the torque level is not enough. You need to do much more than that.
How to Use a Torque Wrench on Sequence Bolts?
Sequence bolts are the bolts you find on cylinder heads, water pump and so on. They require precise fastening if you aim to keep these parts in good health all the time.
Of course, the first thing is to refer to the car manual to know, as to what torque level you should fasten these bolts.
Even if you do not have the car manual, just get on the manufacturer’s website to find out. You may even send them an email to confirm.
Once you ascertain the torque level to apply on the bolts, a newbie will want to hit the ground running, that is, apply torque on the first bolt, complete it and move on to the next one. That is so WRONG!
As you start, torque the first bolt to a ¼ of the total torque level needed. You can then proceed to the next bolt in line and repeat the same. Continue until you finish with all the bolts. At that juncture, all the bolts will have the same torque level.
Proceed to torque them to ½ of the required torque value. This time, do not start with the same bolt you started with when applying ¼ torque. Start with the last one. Keep changing them like that even when applying ¾ torque, up until you get to the full torque.
By the time you finish, all the bolts will have been tightened to the same torque without any one of them causing undue tension or cracks on any part.
How to Tighten Wheel Lugs with a Torque Wrench?
As we said at the beginning, torque wrenches are used mostly for tightening wheel lugs on trucks, buses, cars, etc.
You may have seen mechanics using pneumatic torque wrench to tighten bolts on a semi. They torque the first bolt to the total torque, say, about 200 ft.-pounds, then proceed to the next bolt and so on. That is so wrong. In fact, it is a big mistake.
When you torque the first two lugs, you will pull the wheel to lie on the brake drum on one side. Even when you torque the other lugs fully, the wheel will simply refuse to align. Thus, the driver will be driving around in a truck with wobbling wheels.
Need we mention the danger or the damage such a wheel can cause? The right thing to do is to torque all lugs to the same amounts of torque. You may then proceed to the next level equally until you complete it.
If the bolts that you are tightening are in a circular pattern, such as on a vehicle wheel, tighten them in the start sequence. Start with one, and then go to the one opposite it, rather than the one next to it.
Matching the Right Torque Wrench with its Job
Finally, use right torque wrench for the job. Hands down, the click torque wrench is best for automotive repairs. After tightening the bolt to the maximum level, the torque wrench makes a click sound. When you hear that click, stop immediately, do not fasten anymore or you will over-torque the bolt.
You must know torque level recommended by the manufacturer. If it says to torque the wheel lugs to 120ft.-pounds, get a torque wrench rated for that or more. If you can reach the bolt you are tightening, fasten it as far as it will go by hand before using the wrench. Also make sure it is rust - free.
Choosing the best torque wrench for your DIY or professional automotive repairs is not enough. You need to know how to use it to tighten parts. If you are tightening bolts in a sequence, you now know how to do it the right way. That way, you will preserve life of your bolts and other car parts.