The symptoms that usually indicate worn inner tie rod sockets are a "loose" feeling in the steering wheel, steering wander and/or toe wear on the front tires.
Badly corroded inner tie rod sockets will sometimes bind, causing poor steering return and/or hard steering. Overtorquing the sockets during installation can also produce the same kind of symptoms. In most instances, though, hard steering and poor steering return indicate binding elsewhere, such as in the outer tie rod ends, MacPherson strut upper bearing plates, or lower ball joints.
Noise is another symptom that's sometimes blamed on worn inner tie rod sockets. But a more likely source of knocking or clunking in the steering is excessive play in the rack itself (which a yoke adjustment may or may not help) or bad rack bushings.
In any event, don't jump to conclusions until you've made a thorough inspection of the steering gear, suspension, wheel bearings and tires to determine the exact nature of the problem.
STEERING RACK INSPECTION
The best way to inspect a front mounted rack & pinion steering unit is to use the "dry park" check. Both front wheels should be on the ground or on the runways of a lift (lock the turn plates if the vehicle is on an alignment rack) to load the steering gear and linkage. Have a helper rock the steering wheel back and forth while you watch for any looseness in the tie rod ends, steering shaft linkage or rack bushings.
Watch closely for any slop between the intermediate steering shaft and its couplings. The swivel joints used on some older cars are exposed to the elements and are vulnerable to corrosion. Even if the shaft couplings are surrounded by a protective cover, push the cover back to check their condition. Looseness or binding here is an often overlooked cause of a lot of unnecessary R&P steering work.
The rack housing should not move with respect to the crossmember or chassis. Movement would indicate loose rack bushings and/or a cracked or broken mounting ear.
You can't see looseness in the inner tie rod sockets with a dry park check because the bellows are in the way. With rubber bellows, however, you can usually "feel" any slop in the joint by pinching the socket with your fingers. The hard plastic Hytrel bellows that GM has used on older cars are not very pliable, so on these vehicles you either have to pull the bellows back and visually check for looseness or use the alternate "rock the wheel" method of inspection.
Lock the steering wheel, raise one wheel off the ground, then grab both sides of the wheel and try to rock it back and forth. Any in-and-out movement of the tie rod at the bellows means the inner tie rod socket is loose. This technique is also a good one to use on firewall and rear cradle mounted racks where access is a problem.
Note the condition of both bellows and their clamps. Torn, age- cracked or oil-soaked bellows and/or loose clamps should obviously be replaced. If dirt and/or water have gotten inside, chances are the inner sockets and possibly the rack itself may also need attention.
The presence of power steering fluid in either bellows of a power rack indicates an internal seal leak, and unless you're adept at overhauling power racks yourself, a leak means a replacement rack.
If your inspection uncovers a problem with the inner tie rod sockets (or the rack itself), the next step is usually to pull the rack. The inner tie rod socket assemblies on some cars can be replaced with the rack in place, but on most there isn't enough elbow room to do what has to be done.
STEERING RACK TEAR DOWN
One you've extracted the rack from the chassis and have it on your bench, mount it in a rack vice or clamp one of its mounting ears in a bench vice. What ever you do, don't squeeze the rack housing in the jaws of a vice because doing so runs the risk of crushing the housing.
Even if only one socket appears to be bad, remove and discard both bellows. As with outer tie rod ends, if one is bad you can bet the other isn't too far behind. An inner socket will sometimes fail prematurely because it was installed too tightly or because it's protective bellows was damaged. But most of the time the socket fails as a result of normal wear and tear. And since both inner tie rod sockets receive the same about of abuse, the amount of wear is usually the same in both -- so both are likely to need replacing. Pulling the rack out of the car is usually the toughest part of the job. That's why many experts recommend replacing both inner sockets (and bellows) at the same time when one or the other has failed under "normal" circumstances.
There's another reason for removing both bellows. If you're replacing the inner socket on the "long" end of the rack (the one furthest away from the pinion gear), you need to hold the rack to prevent it from twisting while replacing the socket. If you don't hold the rack, it will twist against the pinion teeth and possibly damage them. The only acceptable way of holding the rack is with a wrench on the flat portion of the rack where the teeth are cut. Using a pair of Vice Grips or a pipe wrench to hold the rack is a no-no because the teeth on either tool will dig into the rack, leaving nicks behind. The nicks will then chew away at the end seals in a power rack every time the rack slides back and forth. Before long the rack will begin to leak again.
A third reason for removing both bellows is to replace them with new ones. Rubber bellows deteriorate with age, and the older they get the more likely they are to crack. If the rack has accumulated enough miles to need new inner sockets, it likely needs new bellows.
Hard plastic bellows, on the other hand, are more resistant to ozone and oil contamination than rubber so it might be argued that replacing plastic bellows as a preventative measure is unnecessary. Even so, the bellows should be carefully inspected and replaced if found to have any damage.
INNER TIE ROD SOCKET REPAIR
With the bellows removed, you'll find a variety of inner socket configurations. Inner sockets are threaded onto the rack and are locked in place by one of several means to keep them from working loose. The housing itself may be staked to the rack, or it may be held by a jam nut, lock pin, roll pin or set screw.
Jam nuts or staked housings can be loosened with a crowfoot wrench, pipe wrench or locking pliers (on the socket housing, not the rack!). But before you try to unscrew the socket, extend the rack towards the "short" side (the end with the pinion gear) and hold the rack with a wrench across the rack teeth to prevent it from twisting.
On sockets held with a spiral roll pin, use an easy out tool or a small slide hammer to extract the pin from the housing.
To remove a socket secured with a lock pin, you'll have to drill the pin out with a 5/32 bit. Extend the rack fully towards the side being repaired, and wrap a rag around the end of the rack housing to keep out metal chips. Center punch the pin to position the drill bit, then drill to a depth of 1/4 to 3/8 inch. Once the pin has been dispatched, you can loosen the locknut and back off the socket.
Be sure to clean and inspect the rack threads. If the threads are damaged or if either end of the rack has more than two holes in it, the steering gear must be replaced.
Some import racks (AMC Alliance/Encore w/manual steering, Toyota, and Nissan) are threaded internally for a male inner socket. A lock washer or lock plate is used to secure the socket. To remove the inner socket on the Alliance/Encore, a special tool is required. Don't reuse the old lock washer.
You can now install the new inner socket assemblies. Preassembled aftermarket sockets do not require lubrication, but original equipment multi-piece sockets do. Use a good quality multipurpose grease or wheel bearing grease to lube the socket and seat.
How the inner sockets are installed will depend on the type of rack and replacement socket used. The preassembled aftermarket sockets are usually "pre-loaded" which means the socket carries the right amount of tightness as is. To install this kind of socket, all you do is thread it on, torque it in place, and then lock it with the appropriate locking device.
With OE multi-piece type sockets, however, the socket has to be torqued until the specified preload is established -- which you measure with a pull scale. Generally speaking, the socket is tight enough when it takes about 4 to 6 lbs. of force to move the tie rod sideways. If the socket isn't tight enough, it can create play in the linkage or hammer out and become loose. Get it too tight and it can bind or wear prematurely. That's why the preassembled aftermarket replacement sockets have become so popular.
Thread the jam nut and new socket onto the end of the rack and tighten to the manufacturer's recommended specifications. Make sure the tie rod moves freely before staking or locking the socket in place.
On GM racks that require staking, stake both sides of the housing with a drift. Support the rack while you're doing this, and stake the housing so a 0.010 inch (0.25 mm) feeler gauge can't be passed between the rack and housing stake.
On sockets that require a lock pin, center punch and drill a hole no more than 1/4 inch deep to accept the new lock pin. Drive the pin into the hole and peen the surrounding metal to help secure the pin in place. Locking compound should be used on the threads of set screws.
On many applications, the positioning of the inner sockets on the rack is crucial. The rack must first be centered in the housing so that an equal amount of rack sticks out each end of the housing. The inner sockets should then be threaded on until the innermost edge of the sockets are at a specified distance from the housing. Refer to the vehicle manufacturer service information for details.
REINSTALLING THE STEERING RACK
Once you've finished your inner socket R&R, be sure to refill a manual rack with 90 weight gear. Most manual racks hold about 0.2 pints (95 ml). A power racks can be lightly lubed with chassis grease.
Center the rack, and position the new bellows so the rack has its full range of travel in both directions. Use new clamps and make sure the bellows are not crimped or twisted. On power racks, make sure the vent tube that runs end to end fits into the holes provided in the bellows and that the tube is not crimped or obstructed.
When the rack goes back in the car, most experts recommend installing new mounting bushings. Any rack with enough miles on it to wear out the inner sockets is likely in need of new bushings, too. And labor, after all, is the biggest part of the job.
On Ford racks with three mountings, tighten the center bushing first, then the two end bushings.
With power racks, air will have to be bled from the system once the rack is back in place. Top off the power steering reservoir, start the engine and turn the steering side to side (without hitting the stops) to purge the air from the system. Add fluid as needed to maintain a full level.
The final step is to reset toe alignment. Changing the tie rods will alter the original adjustment so don't skip this vital step.