25 Top Fixes for Your Mustang
How To Repair the Most Common Mustang Ailments
From the January, 2004 issue of Mustang Monthly
Ah, the joys of Mustang ownership. Sometimes, the Mustang is a ride we love to hate. We fuss about the things that bug us. And we look at these American icons with the kind of rush of emotion associated with a best friend we're having a spat with. Yet, year after year, show after show, we continue to drive them, show them, and pamper them. Call it a prestigious form of insanity. It's hard to believe we could limit this topic to just 25 vintage-Mustang problems, but we're going to show you some of the more common Mustang ailments and how to fix them.
If you own a '65-'69 Mustang with low-back bucket seats, you've probably dealt with this one. The problem of broken seatbacks applies mostly to '68-'69 Mustangs, where the pivot pin fails and you wind up in the back seat. Not only is it embarrassing, it's unsafe. More common with '68-'69 Mustangs, it also happens with '65-'67 models, and with the same result. We just have to address the fix differently. The '65-'67 seatback tends to fail two ways. One is pivot-pin failure. Another is failure of the adjustable seatback stop in the seatback, causing it to fall back into the rear seat. In 1980, Ford issued a recall on '68-'69 Mustang and Cougar seatback failure. Ford dealers were issued two seatback repair kits, D7ZZ-69618C46-A and D7ZZ-69618C47-A for left and right bucket seats. These repair kits are a simple bolt-on fix for '68-'69 Mustang bucket seats. They are available from Mustangs Etc., Dept. MM, 14843 Bessemer St., Van Nuys, CA 91411, 818/787-7634, www.mustangsetc.com. Kit availability is subject to change because they are N.O.S. (new old stock).
One of the Mustang's greatest shortcomings from '65-'70 is leaking cowl vents. Because the cowl-vent assemblies (called the balloon assembly) were never protected from corrosion, they started leaking almost immediately. In fact, there was a factory Technical Service Bulletin issued in 1965 for this problem. The factory fix was little more than liberal doses of body sealer around the cowl-vent dam on both sides--merely a bandage on an infection. If your Mustang's cowl vent is leaking water into the interior, you have a few solutions. One involves splitting the cowl and repairing the leak, which means drilling out a couple hundred spot welds. Not an easy task, but necessary. Another solution, depending on the condition of your cowl, is to install cowl-vent repair "hats" to keep the rain and wash water at bay. These kits are available from California Mustang, Dept. MM, 19400 San Jose Ave., City of Industry, CA 91748, 800/775-0101, www.cal-mustang.com. For a more detailed look at cowl-vent repairs, see the Sept. '03 issue of Mustang Monthly.
These days, Vintage Mustang seats suffer from old age. When it's time to adjust them, they stick, hang up, and provide us with a lot of frustration. But it doesn't have to be this way. Crawl underneath the car and remove the seat bolts. Yank out the seats and carefully remove the seat return springs, protecting your eyes and face. Take a large No. 3 Phillips screwdriver and remove the seat tracks from the seats. Clean the seat tracks in diesel fuel or a suitable solvent with a stiff-bristle brush. Then wash them thoroughly with soap and water. Spray the tracks with WD-40 lubricant and give them a gentle dose of white lithium grease on their contact surfaces. When you reinstall the seat tracks, move both sides to the same position--either all the way forward or all the way back. Lock both tracks, then reinstall the return springs before reinstalling the seats.
Mustang window regulators weren't superior quality to begin with. In fact, the Mustang's windows are as legendary as the nameplate because everyone remembers trying to roll them up quickly--unsuccessfully--in sudden rainstorms. Mustang windows don't roll up or down for the same reasons seats don't slide forward or backward. Dirty tracks and rollers slow them down. Binding window glass slows them down. Stripped-out window regulators slow them down and stop them from working entirely. When cleaning doesn't work, order a new set of window regulators from Year One, Dept. MM, P.O. Box 521, Braselton, GA 30517, 800/932-7663, www.yearone.com.
Door locks quit for the same reasons seats don't slide and windows don't roll up or down. They get dirty and wear out. We forget these cars were designed to live happily for five to seven years at best. The darned thing is worn out ... or is it? Despite the short expected lifespan of our Mustangs 40 years ago, they've held up decidedly well, including stubborn door locks. Disassemble your door-latch mechanisms and wash them thoroughly in solvent. Then treat them to liberal doses of white grease and WD-40 around the moving parts. When they're reinstalled and working, you will be amazed at the result. While you're at it, install new door-lock buttons and grommets for smooth operation.
6 Squeaky Upper Control Arms
Mustangs, Falcons, Comets, Cougars, and Fairlanes all suffer from squeaky upper control-arm bushings. Ford didn't fit the upper control-arm bushings with grease fittings when these cars were assembled four decades ago. As these cars are driven, upper control-arm shafts and bushings wear out, displacing the dried-out grease. Through the years, cutting torch mechanics have blown holes in the shock towers to install grease fittings in the arms. By the time this happens, the damage is done to both the arm and tower. Solution? Replace the upper control arms and spring perches, and start over with a new high-maintenance regimen. Install 90-degree-angle grease fittings in the new arms and service them regularly. For more information, contact Mustangs Plus, Dept. MM, 2353 N. Wilson Way, Stockton, CA 95205, 800/999-4289, 209/944-9977, www.mustangsplus.com.
This one will take you by surprise, usually when the night is darkest and you're on unfamiliar backroads. When headlights cycle off and on in a regular rhythm, your headlight switch is faulty. It is actually a faulty headlight-switch circuit breaker that heats up from corroded and dirty contacts, forcing the breaker to cycle open and closed. The fix is to replace the switch. While you're at it, check your Mustang's headlight circuit for any short circuits that might be tripping the headlamp switch's built-in circuit breaker. For more information, contact Virginia Classic Mustang, Dept. MM, P.O. Box 487, Broadway, VA 22815, 540/896-2695, www.vamustang.com.
8 Leaking Windshields/Backlights
Mustang windows are traditional leakers, regardless of what your windshield shop says. It takes extraordinary patience (and persistence) to stop the leaks. When you're installing a Mustang windshield or backlight, those rubber gaskets need special attention. There are a couple of acceptable approaches you can use. One is the use of the endlessly pliable, black, yucky, gooey windshield sealer between the glass and gasket, and between the gasket and body. Once installed, you take this gooey, petroleum-based sealer and apply it between the gasket and body, then install the molding. Another approach is the use of 3M's Window-Weld instead of the petroleum sealer. However, Window-Weld becomes permanent, which makes it necessary to replace the rubber gasket should the windshield or backlight ever need to be replaced. The nice thing about Window-Weld is that it seals better and is less prone to leaking once it sets up. In any case, you need sealer between the glass and gasket, and the gasket and body. Once installed, you need a solid bead of sealer around the windshield or backlight between the gasket and body to keep moisture out.
Most of the time, crummy performance happens as a result of improper tuning. There are a lot of misconceptions about tuning, but two basic fundamentals always prevail: ignition timing and fuel delivery. Two simple tuning rules apply. Ignition timing has to follow the rpm curve. At idle, ignition timing should be around 6-10 degrees BTDC (V-8 engines). At 3,500 rpm, the ignition timing should jump to 39-41 degrees BTDC. Never push the total advance beyond 41 degrees BTDC. Adjust the vacuum advance so it doesn't come on too quickly or too slowly. Too quickly and you'll get detonation and spark knock. Too slowly and your Mustang will fall on its face. Spark timing happens in two places: the vacuum advance and centrifugal advance. The vacuum advance does its work during acceleration. Centrifugal advance comes into play once the engine arrives at higher rpm. The vacuum advance works during acceleration, giving way seamlessly to the centrifugal advance when the car reaches cruising speeds. Fuel delivery is a matter of having the idle-air adjustment set properly for a smooth, balanced idle. If it surges at idle, the idle-air mixture is too lean on one side. High-speed fuel delivery (off idle) is controlled by the jetting. Too rich and spark plugs foul. Torque will improve with a rich mixture, but the engine will feel awful at speed. Too lean and the spark plugs become chalky white as the engine surges and misfires. You also stand a chance of blowing holes in the piston domes. Pony Carburetors can help with all of your classic Mustang carburetor needs. PerTronix can help on the ignition side with the Ignitor and Ignitor II drop-in electronic ignition modules for vintage Autolite and Motorcraft distributors. For more information, contact PerTronix, Dept. MM, 440 East Arrow Hwy., San Dimas, CA 91773, 909/599-5955, www.pertronix.com. Pony Carburetors, P.O. Box 420, Cazenovia, NY 13035; 315/662-3003, www.ponycarburetors.com.
This one always stumps us. It happens when we're on the interstate or it captures our attention on a rainy night, just after punching the time clock, leaving us stuck in the parking lot. Why do batteries go dead? And why do charging systems stop charging? With older Mustangs, there are two basic areas: alternator/generator and voltage regulator. In newer Mustangs, with an integral voltage regulator inside the alternator, it is the regulator. Most of the time, old or new, it is a faulty voltage regulator. Any starter/alternator shop can check your alternator or generator for proper function. Ditto for the voltage regulator. If you are replacing the alternator or generator, install a new solid-state voltage regulator. While you're troubleshooting, check all of your electrical-system grounds. Faulty grounds cause all kinds of unexplainable electrical-system gremlins. Don't forget one other thing: a fan belt that's properly adjusted. For more information, contact AMK Products, Dept. MM, 800 Airport Rd., Winchester, VA 22602, 540/662-7820, www.amkproducts.com.
Most of the time, it's that annoying drip on the white concrete driveway or garage floor. The power steering works, but it leaks! Why is the Mustang's Bendix power-assisted steering such a pain in the posterior and what can you do about it? Whenever you install new power-steering hoses, make sure they are properly routed and mounted, and be sure they aren't rubbing against anything. Tighten all fittings securely. Power-steering components give us grief because we don't maintain them. Inspect your Mustang's power- steering system whenever you check the oil, and tackle any leaks the minute they show up. Change your power-steering fluid whenever you service the transmission and rear axle. Clean power-steering fluid is the key to seals and hoses staying fresh.
12 Parking Brake Sticks/Doesn't Work
We're convinced classic Mustang parking brakes were never really designed to work. It doesn't matter how many of them we have seen in restored Mustangs--they never really work properly. The '65-'68 Mustang's hand brake has never been a reliable performer. The best advice we can offer is to make sure the cable is clean and lubricated. Inspect the rear drum brakes regularly. Adjust the cable underneath so the rear brake shoes have a solid grip when you set the brake. Ford did away with the antiquated hand brake beginning in 1969.
Ah, yes--the proverbial broomstick in a barrel, the sloppy Joe, the old "find me a cog!" experience. Stock Mustang manual shifters take a lot of practice to overcome and use. You grab the little wooden ball with an "H" on it and try to find First gear. It can't be done. It's somewhere over there and up there. But did you know these shifters weren't all that bad when they were new? Time and use have worn them out. All you have to do to get your Ford shifter back in the "H" is order a shifter rebuild kit from your favorite Mustang parts vendor. Then tear it apart and replace the side bearings, which are nothing more than aluminum discs supported by springs. These discs give the shifter handle something to ride against when you're going for First, Second, Third, or Fourth gear. Lubricate these discs whenever you change oil and lube the chassis. And when the discs wear out, replace them and save yourself frustration.
14 Sloppy Automatic Shifter
Like the beloved manual shifter just addressed, automatic shifters wear out too. But the automatic shifter is easy to disassemble, rebush, reassemble, and return to service. In fact, it should take an hour or less. The automatic-transmission shifter lever rides on plastic bushings similar in appearance to the brake and clutch-pedal bushings located under the dashboard. All you have to do is disconnect the shifter from the transmission underneath, then remove four machine screws and remove the shifter. Bushing replacement comes by removing the shifter-handle retaining nut, then removing the handle. Bathe the new bushings in white grease, then reassemble the shifter. For more information, contact Laurel Mountain Mustang, Dept. MM, Rte. 2, Box 163, Sunny Dr., Ruffsdale, PA 15679, 888/925-7669, www.laurelmountainmustang.com.
Vintage Mustang doors make a distinctive sound when closed; they make our steeds sound like rattletraps. Few things are more embarrassing than a runaway door that won't stay open. Or worse--a stray door that smashes our shins getting into or out of the car on a hill. Mustang door hinges are multifaceted, and we have a lot of issues with them. Doors sag. Doors won't stay open. Fortunately, there are fixes for both. Regardless of your Mustang's vintage, you can rebuild the door hinges. All you need are new pins and bushings to get them in proper alignment. When doors fail to stay open, the check mechanism has given out. When this happens, the checks, rollers, and springs need replacement. New rollers need lots of lubrication between the roller and pin. A light dose of white grease between the roller and check will make for smooth operation. Use a Ford spring in the check mechanism for best results. However, use high-quality reproduction hinge-pin and bushing kits. The Ford bushing and pin kits aren't designed for early cast-iron hinges.
This is the Centerforce Dual-Friction...
This is the Centerforce Dual-Friction diaphragm-styleclutch. Those little flyweights are what make this clutch work soeffectively. The faster the engine spins, the harder the clutch holdsthe disc
Clutch pedal effort is one of the biggest Mustang gripes ever. We hate the way they feel because they are so stiff. However, we're glad if the darned things work at all. Despite the two basic methods of doing away with classic Mustang clutch linkages, there is a solution. First, replace the entire clutch linkage, beginning underneath the dashboard with the pedal support and working your way down to the equalizer bar, bushings, rods, springs, and the like. Replace all of it. Then lubricate the pivot points and bushings before replacing the three-finger Borg & Beck clutch with a Centerforce Dual-Friction clutch, which reduces clutch pedal effort because it isn't stiff. If you've had all you can stand with the 19th century equalizer shaft and linkage, we have two promising solutions. The hydraulic-clutch conversion kit from JMC Motorsports installs in your classic Mustang over a weekend, and it will make shifting easier than ever. Another solution is the cable-clutch conversion kit from D.B. Performance Engineering. With the cable-clutch kit, you're installing late-model Mustang technology in a classic Mustang. When you complement these clutch actuation kits with a Centerforce Dual-Friction clutch, shifting will never be dull again.
If you've ever driven a classic Mustang with factory original brakes, you understand how woefully inadequate those old drum binders were. Here's a fix that can save your Mustang, and your life. With Master Power Brakes disc-brake conversion kits, you not only get front disc brakes, you get a dual-braking system to replace the single system on '65-'66 Mustangs. The dual-braking system is designed to give you brakes front or rear should one system fail. All '65-'66 Mustangs need a dual braking system to maintain a suitable level of safety. For more information, contact Master Power Brakes, Dept. MM, 110 Crosslake Park Rd., Mooresville, NC 28117, 888/251-2353, 704/664-8866, www.mpbrakes.com.
We hear this one a lot, especially in the summer. Overheating problems occur when we're not removing enough heat from the engine. The solution starts with a healthy radiator and plenty of airflow. The minimum you should have is a four-row Desert Cooler radiator from Mustangs Plus. Next, don't forget the fan shroud, which channels air through the radiator with authority. Make sure the cooling-fan blade tips are halfway out of the fan shroud, which ensures airflow through the fan. The most efficient cooling fan is a thermostatic clutch fan, which cools as needed. When it isn't needed, it freewheels to conserve power. With a sufficient fan and radiator in place, consider your Mustang's hoses. The lower radiator hose must have a support spring inside. If it doesn't, the hose can collapse at highway speeds, cutting off coolant flow from the radiator to the engine, causing overheating. And, finally, improper installation of cylinder-head gaskets can cause overheating with small-block Ford V-8 engines. Cylinder-head-gasket cooling passages must be located at the rear of the block during installation, which allows coolant to flow at the rear of the block. "FRONT" means front on those head gaskets. Always position the word "FRONT" at the front of the block when you're installing head gaskets. Finally, check your fan-belt tension. A slipping belt will cause overheating.
19 Instruments Acting Weird
Few things befuddle us more than instruments that aren't making sense, like a bouncing speedometer needle, a fuel gauge that registers empty when the tank is full, and a temperature gauge pegging "H" when we are positive the engine isn't overheating. Sound familiar? A bouncing speedometer needle indicates a speedometer head and cable that need lubrication; lots of white grease and WD-40 needed there. Clean the cable and head, then add liberal doses of lubricant. If that doesn't work, replacement of the cable and/or speedometer drive gear may be needed. Electrical instruments work off current flow across the instrument. If all instruments have the same problem (such as all of them reading maximum or all reading nothing), the instrument voltage regulator (also called a voltage limiter) is defective. If one instrument fails to read or reads maximum, the sending unit is defective. It's rare to find a defective instrument. Most of the time, it's a defective voltage limiter or sender.
You could term this one a "fix." If you're doing a cam swap or building an engine, install a hydraulic roller camshaft from Crane Cams. This camshaft grinder on the Florida coast has a roller-hydraulic-camshaft kit for vintage small-block Fords that enables you to run a more aggressive cam profile without the penalty of a rough idle or excessive engine wear. You get power when the revs come on, yet civilized performance for the daily commute. For more information, contact Crane Cams, Dept. MM, 530 Fentress Blvd., Daytona Beach, FL 32114, 386/252-1151, 386/258-6174 Tech Line; www.cranecams.com.
Like those sluggish windows addressed earlier, power windows can get bogged down with yuck and crud, rendering them slow or inoperative. Most of the time, power windows quit due to dirty connections between the motor and power lead. Sometimes, just jiggling the plug at the motor will get you back in operation. We suggest disconnecting the motor and cleaning the plug and terminal with television/radio tuner cleaner. This removes corrosion and crud, allowing electricity to flow again. Another problem is dirty brushes and armature, which make the motor quit for the same reason: no electricity flow. Clean the brushes and armature with tuner cleaner for the same results. As always, check the plug with a voltmeter or a test light to be sure you have electricity flowing to the motor.
Turn-signal switches rarely fail. But when they do, it can be darned inconvenient. Sometimes, it's downright frightening, especially when there's a semitruck bearing down on us. Why do turn signals fail, and what's the fix? Switches fail for a variety of reasons, mostly due to corroded or dirty contacts, which limit or stop the flow of electricity through the switch. Considering the location of a turn-signal switch--in the busy area inside the steering column and behind the steering wheel--failure doesn't surprise us. The turn-signal switch's contacts, which ride the steering-wheel slippery rings, get quite a workout. Dust, dirt, and crud find their way up the steering column from the engine compartment, adding insult to injury. Dirty contacts create resistance to the flow of electricity, which makes heat. And here's another one you probably haven't thought of: If you keep blowing fuses or cooking turn-signal switches, check and replace all of the turn-signal and parking-lamp bulbs. Bulbs sometimes short internally when their filament posts bend over from heat and short against each other. Check this first whenever you blow a fuse.
This isn't a common fix, yet it should be anytime you build an engine or do a valve job. Hardened exhaust-valve seats are a must if you drive your Mustang a lot or do a lot of hard driving. Prior to 1972, Ford's engine valve seats were made of iron, which worked just fine when gasoline still contained lead. In fact, they were little more than a machined-iron surface in the iron cylinder head. Hardened valve seats are separate steel inserts that are installed in the cylinder head during a valve job. If you trailer your Mustang or drive it rarely, don't sweat the hardened seats. Your money is better spent elsewhere.
24 Battery Apron Rusts Out
Battery acid is hell on anything it touches. This is why inner-fender aprons and battery trays rust out with regularity in older Mustangs. You can replace the inner fender and battery tray, or you can cut and patch using a reproduction apron. A good rule of thumb with rusted-out battery trays and aprons is to protect the new steel with a good self-etching epoxy primer/sealer. Then apply several thin coats of satin black. For sheetmetal information, contact National Parts Depot, Dept. MM, 900 S.W. 38th Ave., Ocala, FL 34474, 800/874-7595, www.npdlink.com.
Have you ever moved the climate-control switch to HEAT and had cold air in your face instead of warm air on your feet? What about that 95-degree day last summer when warm air blew from the outlets because the A/C compressor wouldn't engage? Your Mustang's in-dash A/C system ('67-'73) operates with engine manifold vacuum to move its air doors and hot-water valve. Slide the selector to FRESH and you're bringing in outside air, coupled with air-conditioning compressor engagement for cooling. Slide the knob to MAX and you close off outside air, recirculating cabin air, with the air-conditioning compressor engaged. Go to HEAT to direct fan air to your feet. Slide the TEMP knob, and you direct vacuum to the hot-water valve, allowing hot engine coolant to circulate through the heater core. DEF (Defrost) moves the doors to direct hot air to the outlets on top, defrosting the windshield. A/C is also engaged in DEF mode, which helps dry the air. Proper operation of the vacuum-operated doors and hot-water valve relies on vacuum hoses that are connected properly. When these doors aren't opened or closed when they should be, your Mustang's climate-control system isn't going to work properly. Consult a vacuum diagram and connect your climate control's vacuum hoses properly. To get a vacuum schematic, a Ford shop manual, or a Mustang assembly manual, contact Jim Osborn Reproductions, Dept. MM, 101 Ridgecrest Dr., Lawrenceville, GA 30045, 770/962-7556, www.osborn-reproduction.com.