Maintenance

Suspension tips and tricks

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Suspension tips and tricks

In this brief article, we highlight a few suspension service tools, along with guidance tips for specific vehicle applications, as well as must-know wheel fastening tips.

Mobile hydraulic press

As with many tools, components, system designs and techniques, there’s “old school,” and there’s “new school.”

When it comes to servicing suspension bushings, ball joints and wheel bearings, traditional methods of separating interference-fit bushings, joints and bearings typically involve pickle forks and hammers, manual or hydraulic pullers, scissors/clamshell ball joint separators and the like.

A “new school” approach (this one from Schley Products) involves an all-in-one mobile hydraulic press system that apparently does it all with a minimum of fuss. The 11000A features an air-powered hydro pump with foot control.

Honda/Acura ball joint tool

Schley Tools has introduced a unique lower ball joint service tool specifically for Honda/Acura applications. The new tool allows removal and installation of the lower ball joints on the car, eliminating the need to remove the steering knuckle and using a stationary press.

The tool features two main parts that attach to an air hammer (remover and installer tools). The installer tool couples with one of three different sizes of installer heads that drive the new joint into place without damage.

The tool system covers 1991-97 Honda Civic, 1990-2002 Accord, 1988-91 & 1996-98 Prelude, 1995-97 Odyssey; and 1988-95 Acura Legend, 1992-2001 Integra and 1996-2003 TL.

Pivot-jaw ball joint separator

The “scissors” or “pivot-jaw” type ball joint separator features two forged halves that share a common pivot point. A cupped-out seat engages on the opposite side of the joint from the stud and the driver side of the tool jaw engages the stud tip. As the captive threaded bolt at the opposite end of the tool is tightened, the jaws that capture the joint compress, popping the interference-fit joint out of its home. The tip of the adjuster bolt features a ball bearing to prevent the stud from digging into the tool’s drive end as the bolt is rotated.

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The pivot point features two choices (pop the pivot pin out, adjust for a tighter or wider jaw distance and reinsert the pin into the appropriate pivot hole). The tool is adjustable to accommodate up to a two-inch spread for different size ball joints. This handy style joint separator can be used on various styles of ball joints as well as certain styles of outer tie rod ends.

Using compressive force as opposed to impact force allows a controlled separation, reducing the chance of damaging adjacent surfaces. This style of tool requires no hydraulic assistance, and it’s a handy item to keep in your arsenal of suspension specialty tools.

An example of this style of tool is OTC’s Ball Joint Separator P/N 6297.

PT Cruiser watts link

One of the most common wear items on Chrysler’s PT Cruiser is the rear watts link. This is a cast iron bellcrank that is located on the center on the rear suspension axle/crossmember. The center of the watts link bellcrank is attached to a fixed point on the crossmember, and is positioned vertically, with an eyelet at top and bottom. The left side track arm connects to the bottom of the watts link bellcrank and the right track arm connects to the top of the watts link.

The purpose of this setup is simply to locate the body relative to the rear axle (with the two track arms serving as lateral braces). It’s a simple and effective design that has been used in race cars for decades. As the suspension lowers or raises, the watts link bellcrank pivots, allowing one track rod to lengthen and the opposite track rod to shorten. This provides lateral limitation of the body during either left or right hand turns. It’s a good design that works well.

However, the PT Cruiser’s OE watts link features a cheap and poorly designed pivot bushing, requiring that the watts link must be replaced (depending on driving habits) every 10,000 miles or so. When the owner of a PT Cruiser complains about a clunking or thumping noise from the rear whenever they drive over a bump or other irregular road surface, chances are very high that the watts link is the culprit (when you hear the noise from inside the vehicle, it initially sounds like the top of the rear struts are loose).

The center pivot bushing (where the watts link attaches to the rear axle/crossmember) features a bronze bushing that’s encapsulated in rubber. The rubber deteriorates, the bronze bushing moves around, and while the link actually remains somewhat functional, the loud thumping noise will drive you nuts. Many PT Cruiser owners tend to panic due to the nature of the noise, assuming that they have a catastrophic problem. A replacement watts link usually runs around $48, and requires only about 30 minutes to replace, so it’s not that big of a deal.

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By the way, while you can plan on replacing the watts link every XXXX miles or so, here’s an option: Energy Suspension makes a replacement urethane bushing for the link. Press out the original bushing and pop the two-piece urethane bushings in along with a steel bolt sleeve. The urethane will far outlive the OE rubber, and the vehicle owner will likely never experience the same problem again (so the next time the vehicle enters the shop with a similar noise, the culprit now may very well be the rear struts).

Spray penetrating oil on the center pivot bolt’s nut (which faces the rear). Using a screwdriver, pry off the black plastic cap from the upper lateral link connection to expose the lateral rod’s nut.

Remove the nut that secures the center pivot bolt. With the bolt still in place, slide the bellcrank away from the axle mount in order to gain access to the lower lateral rod link. Remove the lower link nut, and pop the lower link joint from the bellcrank using a ball joint separator (pickle fork or other appropriate separator). Disconnect the upper rod joint as well. Remove the center pivot bolt and remove the bellcrank.

When installing the new watts link bellcrank, be aware that it must be installed in the correct orientation, as the two ends are not symmetrical. The words “BACK UP” are stamped on one end. The end of the bellcrank with this label must be positioned upward, facing the rear. This stamping must be visible from the rear of the vehicle.

Tighten the watts link bellcrank center pivot bolt to 110 ft.-lbs. The OE spec for the lateral rod joint nuts is 10 ft.-lbs. plus an additional 180 degrees.

Be sure to replace the black plastic cap onto the upper lateral rod connection.

This provides a bit of protection to prevent the joint’s stud tip from hitting the fuel tank in the case of a collision.

 

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2010 Audi A6 rear inner CV joint

For disassembly/assembly of the 108 mm inner CV joint:

1. With the CV shaft assembly removed from the vehicle, secure the drive shaft in a vise, with a shop rag wrapped around the shaft for protection of the shaft surface.

2. Drive the cover down with a copper or brass drift.

3. Remove the circlip.

4. Open both clamping sleeves and remove the protective joint boot from the inner joint.

5. Press the inner CV joint from the drive shaft using special service tool VW 409.

6. Remove the CV joint boot from the drive axle.

7. Slide the joint protective sleeve with a small clamping sleeve on the drive axle.

8. Before installing the joint or triple roller star, splines “A” must be lightly coated with the same grease that is used for the joint.

9. Press the joint on until it dead-stops.

10. The chamfer on the inner diameter of the ball hub (splines) must face the contact shoulder on the drive axle. Use specialty tools VW 522, VW 402, VW 401 and 40-204A.

11. The 40-204A and the clamping surface on the drive axle must be free of oil.

12. Replace the circlip with a new circlip, and verify correct seating of the new circlip.

13. Insert 60 grams of joint grease in the boot side of the joint before installing the protective boot.

14, Install the boot onto the inner joint.

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15. Lubricate the contact surfaces on the cover.

16. Align the new cover using starter bolts (the cover must be precisely aligned with the bolt holes before driving the cover into place). Drive the cover on with a plastic hammer. Install the bolts fully and wipe off any excess lubricant.

17. Position the CV boot in the outer groove (see “2” in the illustration). The inner groove (1) must remain visible for correct installation of the CV boot.

18. Install new stainless steel boot clamps using specialty tool (clamping pliers) V.A.G 1682. Make sure that the edges of the clamping pliers are seated in the corners of the clamp (B).

19. Tighten the clamp by turning the spindle using a torque wrench, tightening to a value of 20 Nm (using a torque wrench with a range of 5 to 50 Nm). Make sure that the spindle threads on the pliers move freely (lubricate with MoS grease if necessary). If the threads are dry and tight, the correct clamping force for the clamps will not be achieved (you’ll obtain a false value with the torque wrench).

Wheel fastener tightening

Never use an impact gun to remove or install threaded fasteners when dealing with custom alloy wheels. The reason to avoid using an impact gun during removal is simply to avoid scratching the wheel’s lug nut wells/pockets. If you insist on removal with a gun, use only a clean socket wrench and run the gun at a slower speed. It’s easy to scratch the wheel’s well pockets with the socket or the exiting nut or bolt, even while trying to maintain control of the gun.

Over-tightening can gall or deform the wheel’s fastener pocket seats. Over-tightening, in its extreme, can create a fracture in the alloy, which can lead to an eventual wheel failure. Excessive over or unequal tightening can distort both the wheel center section and the hub. Considering the lightweight rotor hats featured on many of today’s vehicles, that’s an open invitation to disc brake warping and pedal bounce…which is both annoying and a guaranteed comeback.

When taper or round seat are tightened, an interference fit is experienced — the male seat of the fastener contacts the female seat of the wheel and creates a small wedge contact when tightened, creating a pressure point that helps to lock the fastener in place. If either type of fastener is under-tightened, they can loosen during operation.

If over-tightened, the fastener can become fatigued and can deform the material in the wheel’s female seat pocket, which can result in fastener loosening. The shape of the radiused seat reduces the effect of over-tightening since contact pressure is more evenly distributed than with a taper seat style. Over-tightening can also stretch the wheel studs beyond their designed elastic limit, resulting in potential nut loosening and even stud failure.

Flat seat style is used almost exclusively with alloy wheels, since in the early days of alloy aftermarket wheels, the alloy material may not have been strong enough to handle the frictional forces created by tapered or radiused seats.

Over-tighening a flat seat nut can deform the wheel, causing the aluminum under the washer to extrude, which displaces the aluminum, causing the nut to loosen.

Over-tightening can also stretch the wheel studs or wheel bolt shanks beyond their elastic range. All bolts or studs are designed to stretch a miniscule amount when optimal clamping load is achieved. This elasticity of the stud or bolt is what helps to secure the wheel on the hub. When torqued to specification, this is referred to as achieving the proper “clamping load.” If the stud or bolt is excessively overtightened, it’s possible that it will stretch beyond its yield point, losing its “rubber band” effect. If stretched beyond the yield point, the stud or bolt becomes so weak that it cannot provide the clamping load needed. The result: the fastener loosens or the stud or bolt shank breaks.

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Far too many uninformed do-it-yourselfers approach wheel fastener tightening with the “tighter is always better” attitude. Always follow the torque specifications listed by either the vehicle manufacturer or by the wheel maker. Don’t guess. Actually take the time to pick up a calibrated torque wrench and tighten all of the wheel’s fasteners, in the proper sequence, in several steps to achieve final (and equal) torque values.

As far as thread preparation is concerned, make sure the threads are clean and free of dirt, grease, grit, etc. As far as wheel fastening is concerned, specifications are generally listed based on dry (no lubricant) threads. Applying oil, grease or moly to the threads will result in inaccurate torque values (you’ll end up over-tightening). Even if you use aluminum wheel nuts (which are popular in some racing situations, Porsche applications, etc.), the advice is the same. Simply make sure the threads are clean and dry. Aluminum wheel nuts are typically made from a very dense, strong 7075 alloy, and will function properly if handled correctly. While a race team will use speed guns for quick pit service, you have plenty of time to be careful in the shop, so install the fasteners clean, dry and with a torque wrench.

Retorque

Some will disagree with the need to re-tighten wheel fasteners, but my advice is to re-check the value of each fastener after about the first 50 to 100 miles of operation. Due to metal compression/elongation and thermal stresses, the clamping loads may change during initial use (we’re not saying they will change, but they might). When rechecking torque value, wait for the wheels to cool to ambient temperature (never torque a hot wheel). Loosen and retighten, to value, in sequence. Again, some will argue that this step is not necessary, but it’s better to be safe than sorry, and it’s better to catch a loose nut early as opposed to too late.

Wheel fastener (nut or bolt) torque values

While you should always refer to the vehicle manufacturer’s recommendations for proper wheel fastener torque values, following is a generic guideline (courtesy of The Tire Rack).

SIZE     TORQUE (FT.-LBS.)

10 mm               45-55

12 mm               70-80

14 mm               85-90

7/16-inch           70-80

1/2-inch              75-85

9/16-inch        135-145

Seat styles

The “seat” refers to the contact area between the base of the fastener head and the wheel’s fastener pocket. Although variations exist, three basic seat styles are in common use today. These include conical, radius and flat-seat types.

Conical wheel nuts (or wheel bolts) feature an angled taper at the seat area. Conical fasteners are also called “tapered” or “cone” types. All three names refer to the same style. As viewed from the side, you can see that the seat is “chamfered” on each side of the view. This type of taper is created most commonly in a 60-degree angle, although some light truck applications use a 90-degree angle. The angle indicates the degree of separation between the two walls, not the true vertical of the fastener.

Radius seats are also called “ball” or “rounded” seats. As the name implies, the seat features a radiused “ball” shape that nestles into a ball-shaped pocket in the wheel. Many European vehicles such as Porsche and Mercedes use radius seat styles, in either nut or bolt applications.

The flat seat style is most often called a “mag” style (the term “mag” doesn’t imply anything in terms of geometric shape… it’s simply a slang carryover from the early days of the American performance scene when race wheels were cast magnesium, and commonly used a flat seat because it was easier and cheaper to produce a round hole in a flat hub center area). Mag style (flat seat) nuts generally feature a smooth shank extension under the head, used to center the wheel and to provide needed thread engagement depth.

The golden rule, when discussing seat styles, is extremely simple: NEVER mix them! If a wheel is designed for conical 60-degree seats, the ONLY fastener seat style that can be used is a conical type. The same rule applies for radius and flat seat styles. ONLY use the correct seat style of fastener for the seat style of the given wheel. Using the incorrect seat style can, and likely WILL, result in fastener loosening, wheel damage, and potential tragedy due to loss of vehicle control when the wheel wobbles or separates from the vehicle. It’s simply impossible to overemphasize this point.

The wheel fasteners are the ONLY connection between the vehicle and the wheels. Without proper fastening, you’re flirting with disaster.

The three most important elements of wheel fastening:

1. Proper seat style

2. Correct thread size (diameter, pitch, length)

3. Proper clamping value.  ‚óŹ

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