trustywrench.com

Car Repair

Tips and Tricks

A primary goal of this website is to provide information to amateurs, i.e. those folks who want or need to repair their own vehicle, but who do not fix cars for a living. Today’s subject is a very useful tool that can give a helping hand to the lone mechanic.

This tool is the tie down strap,

a nylon strap with hooks on each end and a cam-lock buckle for adjustment. I frequently use this to hold a belt tensioner, engine part or strut out of the way. A pair of these straps is now my preferred way to lower a fuel tank.

            The most popular tool for releasing accessory belt tension is the serpentine belt tool. This long-handled wrench comes with extra sockets and square drives for various types of spring-loaded belt tensioners. 

 The problem you run into is that it is hard to hold the wrench with one hand and maneuver the belt with the other. I have modified my wrench by grinding a notch at the top of the handle where I can hook the strap. Drilling a hole would also work. Either will probably void the tool warranty. With this modification I can use the tie-down to hold the tensioner back while I work with the serpentine belt.

            Another place this strap comes in handy is for holding components away from the work area. For instance, when removing an intake manifold the strap can hold an A/C compressor or power steering pump off to the side. The trick is to secure the hood with a hood holding tool or broom handle, and then run the strap from a brace hole or latch loop.

            Where I have not seen others use such a strap is in gas tank repair. I now prefer this method over using a transmission jack because of the added control and stability. A transmission jack supports only the middle of the tank and so, as gas sloshes back and forth the center of gravity moves and the tank wants to tip. For long tanks, like on vans, one jack is just too risky. Two jacks would be better, but then you have to step over eight jack feet as you work. Here is my solution: I run two tie down straps under the tank. I hook them to the frame, an exhaust bracket or any convenient hole.  I then can lower each strap a bit at a time until the tank is low enough to access the harness and lines of the fuel pump. If I want the tank all the way out, I lower it onto my rolling cart. This makes the tank easy to work on. For the at-home mechanic this method allows safe tank repairs when the vehicle is on jack stands and you are on a creeper. And best of all, the strap tool is very low cost!

One more reminder: gasoline is explosive! As one who has been covered in burning gas, I say, BE CAREFUL! Not to mention that gasoline still contains benzene, a known and very dangerous carcinogen.

© Walt Christensen 2008

Vehicle brakes come in a variety of designs. This picture shows a late model F-150 rear brake with the parking brake shoes     located inside the disc brake assembly.  The rotor itelf is not in the picture but is being machined on the lathe.

So, here it is December in Wisconsin and one of the snowiest winters in years. I think it is appropriate to say a few words on checking front axle (steering), u-joints in a vehicle that has u-joints rather that CV joints. Since I am still new at web posting I don’t have pictures yet, but will add something soon. First of all, the u-joints in the front of a truck or SUV get more abuse that any others. This is because they are forced to turn shafts at tighter angles than anywhere else on a vehicle, and because they go for long periods without turning at all. Not turning allows the ever-present moisture to build up some serious rust, and then when these joints are used, the rust can prevent the needles from rolling freely. Needles that don’t roll end up sliding on the shaft and cup and get flat spots while gouging the surfaces they contact.Here is how to check for these problems: raise both wheels off the ground, or one at a time, and steer the wheels all or nearly all the way either right or left. With the axle shaft engaged to the hub, spin the wheel by hand.  If the u-joint is in good shape, the wheel will turn freely and with even effort throughout each revolution. A binding u-joint will cause the wheel to be alternately hard to turn then easier through each revolution. Now steer the wheel straight ahead and turn the wheel again. If it turns more freely now, you have identified the u-joint as the problem. Repeat the test to verify your conclusions. Keep in mind that other things can cause hard and uneven turning. A warped and especially a cracked rotor, can cause uneven turning effort, but steering the wheels should not change this. Next, get a look at the joints. Is there obvious looseness? Rust staining that is lighter red that the rest of the rust in the area indicates rust that is getting scoured by movement, like those bearings inside the u-joint.

Why should you care about fixing a tight u-joint in this axle assembly? Eventually the tightness caused by rust will give way to excessive clearance and, over time, damaged shaft parts. Also, a tight u-joint can damage the bearing inside the spindle and the hub innards with excessive side loads. It all adds up to more expense and the possibility of failure when you most need four wheel drive-when you’re stuck!

How to replace these bad parts will be a future topic.

This discussion leads to other related issues, like what are CV joints and why are they becoming more popular than U-joints in some applications? I will post those answers soon.

I now invite you to browse my new car and truck repair tips and tricks website. The goal of this site is to help the weekend mechanic by providing information that will take some of the mystery out of car repair. In the process I hope to hear from other mechanics, who I hope will share their some of their knowledge. Over the years, some of the most helpful repair information I have gotten has come from talking with other mechanics during the breaks between formal training sessions. Likewise, when mechanics move to new jobs there is an exchange of ideas and techniques that helps everyone. Maybe this website can act in that way.

Of course, car repair tips and tricks really is a small part of what it takes to diagnose and repair a vehicle. Mostly, such work is equal parts of intellectual and strenuous physical effort. Why would you want to take on a difficult repair job? The list of reasons probably includes; saving money,  learning about your car and the reward of successfully tackling a problem in a complicated system. Most mechanics get into the business because they just plain like working on machines. A big problem for non-professional mechanics is that they lack the support system that a shop provides. Things like special tools, shop manuals, an engineering hotline and other mechanics to bounce ideas off of.

Another plus for professional mechanics is that they have learned the basic principles that make systems behave the way they do. Problems in systems like air conditioning, brakes and alignment will always be a mystery without a clear understanding of the underlying properties of physics, forces, geometry and materials that automotive engineering is based on. However, once one grasps these issues, correct solutions become obvious. A little studying will make you confident. So, where possible, I will include a discussion of the basics of the system in question. 

In the coming months I will present a series of articles on common vehicle repairs and include photos and graphics to help you get your car back on the road.  And I will sprinkle in some of my own philosophy,  learned along the way, to round out the conversation.

I have been earning a living fixing cars, trucks, forklifts, tractors, and heavy equipment for more than thirty-five years, but no matter how much experience one has, no one knows everything. Use the information you find here, but please, visit the many other good sources and check out their ideas and techniques. Maybe Hillary was right, it takes a village to fix a car.

AND HEY! LET’S BE CAREFUL OUT THERE!