Unusual steering situation, 66-427

[Duke W.]

Re: Unusual steering situation, 66-427

You should definitely inspect the tires per the referenced thread. Your alignment specs are what John H. and I recommend for "touring", with radial tires other than front toe in, which should be 1/32" per side for 1/16" total, so maybe you should have the front toe reset.

Not long ago I replaced the tie rods and center link on my '88 Mercedes 190E 2.6. As usual, it took some time to get the total toe-in to my 1/16" spec with the steering wheel centered. I started off with too much toe and the steering wheel was cocked a couple of degrees CW. This caused pull, but on center feel was good. I tweaked one tie rod 3/8 turn to reduce reduce toe-in in such a way as to clock the steering wheel CCW, and the result was that the steering wheel was near center and the pull was reduced, but it wasn't quit right so I tweaked it another 1/4 turn. The wheel still wasn't quite centered, but it felt numb, and I figured it now had two little toe-iin or maybe even a little toe-out, so I tweaded the other tie rod 1/4 turn to clock the steering wheel CCW and increase toe-in. The test drive felt good - wheel centered with good on-center feel and no pull, and I measured the toe-in at about 1/16".

As usual, it was somewhat of a PiA to get the toe-in that I wanted with the steering wheel centered. I was able to calculate that one full turn of a tie rod changes toe by 3.2/16s, so its a very sensitive adjustment. In the past I know that I've tweaked tie rods as little as 1/8 turn to get things dialed in.

One thing you might consider is removing the belt from the power steering pump, but I'm not sure it you will need to disconnect the ram, too. If you jack the front tires off the ground and can easily rotate the steering wheel, then the non-powered ram shouldn't be an issue. If the problem goes away with the power steering disabled, then that petty much isolates the problem to an issue with the PS system.

Duke

[Richard E.]

Re: Unusual steering situation, 66-427

Thank you Domenic.
I plan to have the alignment re-evaluated this week. At this time I will verify the tow-in is correct and same both sides and have as much caster (beyond 2.5 deg.) added as I can while maintaining 0 degree camber on the front tires. At least that is the plan as of now.

I will also checking into all of the very good suggestions presented here.

[Richard E.]

Re: Unusual steering situation, 66-427

Thanks much Duke, very good suggestion. I have added this to the "to do" list.

Do you think that a power steering issue could cause the car to steer so stiff that even with maximum caster the front wheels will not center themselves?

[Duke W.]

Re: Unusual steering situation, 66-427

I've never worked on the C2/3 PS system. I recall driving C2 or C3 Corvettes with PS and as was typical of that era I felt they were overboosted, lacked on-center feel, and didn't have good wheel returnabililty. The manual system requires more effort, especially with the tie rods set to the fast ratio (PS) position, but other than higher effort it feels great with a blueprinted steering gear and all other joints nice and snug.

Make sure the tie rods are in the correct "fast ratio" holes for PS. I'm surprised you got 2.5 deg. caster while maintaining zero camber, but that is good. It seems that on a lot of cars about all the caster you can get is about 1.5 degrees, and that should be okay for manual steering.

Duke

[Richard E.]

Re: Unusual steering situation, 66-427

Interestingly the car had excellent steering return before the new parts were installed.
I
wish I had the alignment specs from prior to disassembling the car. Keep this in mind guys!

Can you clarify the location fast ratio holes please? Pretty sure we are good here, but I want to check.

Is there anything specific to look at on the tires as a indicator they could be the problem? New tires have little to check from what I can tell.

In the discussion with the alignment shop it was pointed out to me that more caster could be added, but at some point the camber would automatically change casing the wheels to point outward at the top (as a result of adding caster much beyond 2.5 degrees). I don't want this camber change as the tires may rub the body under some turning circumstances.

Thanks Duke.

[Gary R.]

Re: Unusual steering situation, 66-427

Do you still have your original box?

[Bill M.]

Re: Unusual steering situation, 66-427

The symptoms you are describing can be caused by excessive steering friction.

The first thing I would do is grease the ball joints.

If that doesn't fix it, I would disconnect the steering linkage at the wheels and check for one sticky wheel when steering.

Next I would look at the steering gear having too much friction.

The high steering friction is not allowing the caster and KPI centering forces to return the wheels to on-center.

[Richard E.]

Re: Unusual steering situation, 66-427

Hello Gary,
Yes, I have the factory original box. The original plan was to rebuild this box and reinstall, but in an attempt "to save time" I purchased a new box.

[Richard E.]

Re: Unusual steering situation, 66-427

Thanks much Bill, I will try your suggestions on disconnecting linkage and checking friction.

All ball joints are new and came pre-installed on the new A-arms, they have been greased.