Suspension & Steering

Tie Rod Check

Tie Rod Check

The tie rods are prone to failure at the ball and socket connection. To check, unload the wheel/tire and pull/push the tire near the tie rod. If you feel play, it is possibly the tie rod. Have someone else do the tugging while you have your hand on the tie rod. If it moves in place, it will need to be replaced.

Merry motoring, Ed.

I went this morning to have two rear tires, 255/40 x 17 RE730, mounted. When it was on the rack, the front wheels were checked for movement by grabbing the sides and pushing/pulling back and forth. I was called over since there was excessive movement of the wheels and noticable movement under the rubber boot of the inner tie rod, where it connects to the steering rack. We have been experiencing a vibration at about 50mph but could not tell where it was coming from. On the way home I could feel that the steering was not responsive as usual and had some free play. This is my wife's daily driver and I usually do not drive it much. The steering rack was replaced at 60,335 miles with a rebuilt unit, and now the car is at 79,900 miles.

Question to the list gurus, are the tie rods coming undone at the steering rack or did they just go bad? I can't believe that both would go at once in the same manner. I will crawl underneath today and pull the boots back to check them out, but I wanted some advice as to what to look for. The manuals are not very helpful.

Thank you,
1989 928S4, auto

Over time the plastic socket develops some play as it gets worn down by
the metal ball. When that occurs, it's time to replace them. When one
goes, the other will soon follow. YMMV.

~ Merry motoring ~

There are a couple of possible wear/looseness areas:

1) The bushings that support the rack in the rack housing may be worn, allowing the rack to move up and down. Requires a new/rebuilt rack - I am not aware of anyone who can supply parts and seals for a 928 rack.

2) The inner tie rod joints are worn. Requires new tie rods.

3) The tie rod ends are loose on the rack. Requires tightening.

Jack and safely support the car. Loosen the clamps on both ends of each tie rod boot. Clean the tie rod outside of the boot, and slide the boot outward on the tie rod.

Check for fluid in the boot. Fluid here means worn bushings and seals, which requires rack replacement to cure.

Clean the rack.

Check for vertical movement of the rack in the housing. Movement indicates worn bushings, which requires rack replacement to cure.

Check for movement of the tie rods in the inner ball socket. Looseness may be either wear in the joint, which requires replacement of the tie rod assembly; or may be caused by the tie rod assembly being loose on the rack, which requires tightening. Be sure to counter-hold the rack while tightening the large nut, so as to prevent the rack from torquing over against the pinion gear and damaging it.

Grease the rack ends before replacing the boots.

It is possible that the tie rods were not replaced with the rack assembly, and are now worn. If the fault is with the rack, I would check the warranty.

Wally Plumley
928 Specialists

Well I checked my inner tie rod ends and found that they were nice and tight in the steering rack but loose at the ball joint. When you moved a wheel side to side by hand you could see and hear the looseness. I also checked the steering rack itself and found it securely tightened to the chassis. No leaks either under the boots, phew. Big thanks to Wally Plumley and Ed Ruiz for helping out with responses. Great info as always!

Wanted to pass along a little more on this to the list. The source of the vibration, which felt pretty bad at times, could not be determined. The steering wheel does not always shake as if you have a unbalanced tire. What's most disconcerting is the loss of steering feel and slop in the steering. It has gotten pretty bad in a short time. Pretty surprising that they both decided to give up at the same time. I did not change them when I replaced the steering rack since I did not even think about it. I would get them done at the same time, especially if you don't know how old they are.

1989 928S4, Auto

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