Fix Sloppy Steering
|Best Place to buy:|
|Cost to Have it done in a shop:||$|
|How long it may take:||X hours|
|Tools needed:||6mm wrench, 19mm wrench|
|Special tools needed:|
Warning: I would say this is an easy job, but if you don't know what you're doing: don't do it. I don't want any of you to "tighten" your steering incorrectly, and end up loosing your steering and crash and die.
You will need:
- 6mm allen wrench
- 19mm wrench
This is how I did it:
- Jack up the car and support the front wheels off of the ground with jack stands
- Secure enough to run with the front wheels off of the gound.
- On the top of the steering box there is a 6mm allen bolt with a 19mm jam nut
- Loosen the jam nut
- Then loosen the allen bolt until you feel some resistance:
- loosening the allen bolt tightens the steering
- tightening the allen nut loosens the steering)
- Once resistance is felt tighten the nut about 1/2 turn
- Now with one hand on the steering wheel watch the front tires as you wiggle the steering wheel
- I tightened mine until there was like 1.5" to 2" of slack in the wheel
- It may help to have the car running
- Once the desired steering wheel play is set, run the car and test the steering from lock to lock
- There should be no tight spots or noises
- If there are, tighten the jam nut and take it for a test drive.
- Lock to lock tests.
Mine feels like a new car. The allen bolt sticks up about 1/4" out of the jam nut and I am not sure how much more adjusting the threads have left, but i am very happy.
Hope this helps... Happy Motoring!!!!
IDLER ARM BUSHING
My '78 240D was destroying the outer edge of the left front tire very rapidly. I took it to a high end suspension shop, they said it needs all new front end parts, control arm bushings, ball joints etc. $1700.
I had a look myself and noticed the idler arm was real sloppy. I bought one for $30, installed it and now its perfect: no more scrubbing. No alignment necessary though it probably not perfect. Scrubbing is the term used to describe rapid wear from poor alignmnet, the rubber is scrubbed away by the pavement.
Caster, Camber and Toe in. Caster: think of a motorcycle with front forks sloped forward. That slope is positive caster. Cars have just a few degrees of that slope in the front suspension and steering geometry. Your tool cart where the wheels are passive and follow what ever direction you push it is negative caster. Effect of positive caster: when the wheels are strait forward they are neutral and just go strait. Initiate a turn and they want to "dig into" the tun and go that direction more and more. It makes steering more responsive.
Toe in: The two front wheels are normally just a bit directed toward the center line of the car, not strait forward. Thus they work against each other just a little bit to result in stability on a strait ahead path.
If the idler arm is sloppy there is play in the toe in, it cannot hold a stable setting. When the car is in forward motion 1- a bit of toe in plus slop in toe in plus 2- effect of negative caster " digging in to the turn" while in motion: maxes out the "slop" and results in way too much toe in, lots of scrubbing and disappearing rubber. The wheels will sit on an alignement machine strait forward or with normal toe in but while in motion its a different story.
Camber: the wheels are not exactly vertcal. The tops of each wheel are just a bit closer to one another than the bottoms. That's negative (I think) camber. It helps with stability.
Note on why sites like this exist: A MB friend rebuilt the front end on his "68 250S: all new parts. He then took it to that same high end suspension shop for alignment. The put it up on the alignmant machine, "diagnosed" it and told him it needed all new front end parts.
I have a 1983 W123 240D with about 250K on the clock. the front end was very loose... i opted for the $600 in parts only rebuild: Loaded upper control arms, lower ball joints, lower control arm bushings, idler arm rebuild, wheel bearings, tie rod ends.
Hints and lessons learned: Retighten every thing using thread locker and new nylon locknuts!!!!! get a spring compressor first and make sure to have enough bottle jacks around to help pry in the spring, also soe sand bags on the hood or a buddy with a beer belly might be necessary to stop from picking up the whole car. the lower ball joints can be hammered out pretty easily (from the bottom up) the lower ball joint can be pressed in with a hand press (off the car with rotor off and spindle stripped down, remove ball joint dust cover) degrease the car first