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Replacing Tie Rods and Front End Alignment

Gary L. Baker, Esq., Patent Attorney

If you can shake your front wheel and it jiggles where the tie rod attaches to the steering knuckle, you need new outer tie rods.  Should the worn tie rod eventually break, very severe damage would result to your Z, and probably to you. 

The following discussion describes how to change your tie rods and how to align your front tires after replacement of the rods. 

Tools Tools include: metric wrenches and sockets, crow's foot or tie rod puller, torque wrench, 4-foot adjustable spring-loaded curtain rod, grease gun.

1. Jack up and support the front end.  Ensure the parking brake is on and the rear wheels are blocked.  Use jack stands to support the front.  I tend to use redundant supports and even put a stakc of wooden blocks under the front wheels, so there is a back up in case one support fails.  Then, I push and pull on the car to see everything is solid before starting work. 

2. TIE ROD REPLACEMENT: Remove the cotter pin from the castle nut where the driver's tie rod (1 - see Figure, below) mounts to the knuckle (2).   Remove the castle nut (a.k.a., ball stud nut).  The tie rod end is conical in shape and fits into a conical recess within the knuckle.  It usually is not easy to pull the tie rod down out of the knuckle, so I use a crow's foot, shown in the figure, to wedge them apart.  Alternately, a tie rod puller or strong wheel puller the right size can help in the removal.  Typically, I use a large hammer to force the wedge shape of the crow's foot in between the tie rod and knuckle.  While applying force to the crow's foot, I hammer on the tie rod or the tie rod bolt where it extends through the knuckle.  Some times it's easy, sometimes it's not.  With the tie rod removed, clean the inside of the knuckle conical recess where the new tie rod will mount. 

3. Hold the old outer tie rod with one wrench while loosening the lock nut (3 - a.k.a., side rod lock nut) between the outer tie rod (1) and inner tie rod (4).  Note, the driver's side tie rod is threaded in counter-clockwise (non-standard threading) and the passenger's side tie rod is threaded in clockwise (standard threading direction).  Hold the inner tie rod with a wrench and turn out the outer tie rod while counting the number of turns it takes to remove.   (Alternately, you can remember the original tie rod position by marking it with the lock nut.)

4. Thread the new tie rod onto the inner tie rod the same number of turns it took to remove the old tie rod.  Position the threaded conical tie rod end mount in the knuckle, thread the castle nut on to the tie rod thread and tighten to about 50 foot-pounds stopping at a position where the cotter pin can be inserted.  Grease the new tie rod.

5. Alignment Leave the lock nut untightened for now and replace the passenger's outer tie rod, noting the number of turns to thread the passenger's tie rod to the inner tie rod.  Compare the number of turns for the driver's and passenger's side.  Turn one or the other rod in or out so that the both outer tie rods are turned in the same number of turns.   At this point, the driver's side wheel should be about the same distance from the frame with the steering turned all the way right as the passenger's wheel is from the frame when the steering is turned all the way left.

6. ALIGNMENT: I do these measurements with the car on the ground.  If the car was just taken off jacks, roll it a little to relax the suspension into a normal position.  The 4-foot spring loaded curtain rod (about $7 at Wal-Mart or K Mart) changes length when you turn one end relative to the other.   Adjust the curtain rod so that it just touches both front wheels, as shown in the figure, at a forward position.  Position the curtain rod across between the front wheels at a rearward position.  You can't get it all the way back because of suspension parts in the way, but place it as far back on the wheels as you can.  If the curtain rod is tighter at the rearward position than the forward position, your wheels are "toed out"; if the curtain rod is loose at the rearward position, then your wheels are "toed in" (pointing to the center axis of the car).  If the curtain rod touches the wheels about the same front and rear, the wheels are aligned.  


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7. If the wheels are toed in too much (Datsun suggests 3 mm toe in), turn the inner tie rods out from each of the outer tie rods exactly the same amount.  I roll the car back and forth once to let the wheels relax to the new alignment (this may not be necessary, but I have my compulsions).  Remeasure the distance difference between the wheels, front and rearward.  Repeat adjustments until you have the alignment you want.  If the wheels are toed out, with the wheel fronts further apart than rearward, turn the inner tie rods in to each of the outer tie rods the same amount until the are aligned, or with a slight toe in.  When the wheels are aligned properly, lock the adjustment by tightening the lock nuts between the inner and outer tie rods (about 50 foot pounds). 

8. Take your Z for a drive.  Does the car go straight when you let go of the steering wheel on a level road?  Significant misalignment can cause your Z to wander.  When you are going straight, is the steering wheel centered?  If not, you may want to pull the horn pad, remove the big nut, pull the steering wheel and reposition it to be centered on the steering column.  After you have driven the car about 20 miles, or so, rub your hand across the front of the front tires.  You might notice your hand slides easier moving in (toward the center axis of the car), than out.   This indicates the wheels are toed in, with tire wear causing a "feathering" on the inside of raised tread patterns, but rounding on the outside of the tread patterns.  If your hand slides easier moving out than in, this indicates the wheels are toed out.  If you can not detect a difference between the resistance sliding your hand in or out across the front of your tire, the wheels are probably aligned.  Talk about High Tech!

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