Another long winded post because I don't know any other:

Symtpoms: Kinda loose steering, a hard pull to the right, rattling and vibration coming from front end (especially the R side) at high speeds, and now something new (see second paragraph)

During my checking the tie rods showed signs of wear by way of their sagging during detachment with the tie rod ends. Otherwise they didn't show signs of 'slop' that other people on BB said would indicate they were worn. They were last replaced in 1998. Boots torn.

Tie rod ends? I have no clue. I couldn't get the channel locks on them well enough to jostle them. The thing is that the wheels didn't really flex between 3:00 and 9:00, only 12 and 6 (more on that later).


I noticed that the right tie rod had something like 1 - 1.5 more threads exposed than the L (I didn't measure it though, just counted threads). This would be responsible for toeing out the wheel to that side (and it is indeed the side that the car pulls to). SO I experimented with a compensatory 0.5 or so thread reduction on the offending side. I also swapped L and R tires to wear them out equally. Now the problem from this is that during my short test drive the steering wheel was vibrating between 24 and 33 MPH, and the steering was getting noticeably swervy (never ever happened before; it felt crazy unsafe). The correction it provided is irrelevant because now I wonder what is causing that ominous swerve and rattle: the rotated tire, my small compensation in tie rod length, or me somehow bungling the tie rod end removal and reinstallation (I could go in to all kinds of detail about how I couldn't get the lock nuts off and I put a lot of torque on the TR themselves [and also the steering gear itself?], how I hammered on the stud to seperate the ball joint then I had to hold the stud later with another set of pliers to keep it from rotating as I refastened the nut, etc.). Oh yeah and the Bently said to mark the wheel position on the hub before removing, which I failed to notice before I rotated the wheels. So...

Next puzzle piece: Wheels rattle at 12 and 6 o'clock. Both wheels turn freely with only a noise that I would associate with the rubbing of the brake parts against each other (a sliding kind of sound, not unlike the sound of braking itself). So is that freeplay from the ball joint or is it the bearings? No record of either being replaced in my receipt history which dates back 13 years.

The strut inserts are pretty toast and I plan on replacing them. The rack is firmly in place on the crossmember; I'm slowly turkey basting the PS fluid out and replacing with synth ATF 4.

That's pretty much a question every other sentence. Would anyone mind advising? As always, I greatly appreciate it. Thanks.

The thing with front end vibrations, is that, if left uncorrected, they can cause many other parts to wear prematurely. What started out as one problem could now be many.
Here's what I would do.
Since you are already planning to replace the strut inserts, order new ball joints and tie rod ends. Granted, they aren't free, but they aren't expensive either. If the rubber boots on either of these parts are torn, they will be bad shortly, so you might as well replace them.
At least check the inner tie rod ends while you have everything apart. Grab the tie rod and push and pull it back and forth in the direction of the steering rack. Any movement is too much. Check the bearings by trying to rock the rotor at 6 and 12 with the bearing cap off so you can see if the movement is from loose bearings. If they are loose, you may be able to get away with tightening the castle nut a bit. There are two holes in the spindle shaft for the cotter pin, so you don't have to tighten the nut by one complete notch.
Replace the struts, ball joints, and tie rod ends. Replace inner tie rod ends and bearings if needed.
Take the car to an alignment shop and have it professionally aligned. Have the wheels balanced as well.
Get new tires, at least on the front.
Yes, this will be a bit pricey. However, because of the interrelated nature of the front end steering and suspension, you may end up doing all of this in the long run, anyway. When doing it one part at a time, the new parts you install while trying to find the source of the vibrations will wear abnormally until the vibration is corrected. I've been there and done that. Bite the bullet and make sure everything is just exactly perfect. Front end vibrations are DANGEROUS!
--
1966 122s, 1968 142s, 1969 144s, 1979 245dl, 1989 244gl

Thanks Bud. Checking the ball joints (from what I know of checking them, which is not much), they check out OK. Both of them don't have too bad of wear on their boots, and the same goes for the outer tie rods.

Now checking the car one more time, everything seems COMPLETELY different. Wheels have a lot of freeplay between 9 and 3 o'clock (they still jiggle at 12 and 6); the lateral slack is coming from the steering rack! Not the tie rods, but the steering rack from the other sides of the tie rods. I know this because both boots are torn and it's easy for me to see inside there.

So that has me worried that I'm gonna need a new rack. But maybe it can be explained some other way? I sucked out the PS fluid from the reservoir with a turkey baster and put in some synth ATF 4 yesterday and today for good measure, though it never seemed overtly leaky. After I did this again today the steering became squishy and noisy (I'm guessing from sucking air into the rack).

Too late to rewrite my original post. Thank you for your help.

Are you sure it's the rack and not the inner tie rod ends? They are actually part of the tie rods and screw onto the rack.
--
1966 122s, 1968 142s, 1969 144s, 1979 245dl, 1989 244gl

+1 I agree, check for looseness or slop with the inner tie rods before condemning the rack.

yeah pretty sure. The arms of the rack move in and out to the INSIDE of where the tie rods connect! I can see this from the inside of the rack boots because they're torn. I don't know what else to make of it because even though the PS fluid was low following my basting-and-replacing with synth ATF, it is full now and the problem persists. I simply just know know where I would find looseness in the inner tie rods, they're just pieces of metal. Their inner ball joints where they connect to the rack are completely immobile when I push the wheel back and forth....it's all coming from the rack, which even rattles the lower U-joint on the steering column.

For your wallet's sake, I hope your diagnosis is wrong as slop in the steering rack of my 90 244 was the reason I replaced it. Not the usual leaky seals...

It's only 200 bucks and for a rebuilt rack from Jorgenson Automotive Co., and the installation doesn't look impossible, even to this guy. seals or slop, it's still $200. am I missing some caveat about DIY rack replacement? I'd grab one from the pick'n'pull but i'd rather not take the risk, even with my zero-resale-value rust bucket. let me know if I should rethink this, bout to order tomorrow. thanks J

I don't know if I have the same scale of problems, but the steering wheel shakes at 55-60 mph. I had the tires balanced and the front end checked and aligned. The tech didn't find any loose parts. Moving the wheels around makes very little difference. My next step is to have a close look at the wheel bearings.

Three suggestions: 1)Check what you have for toe in, 2) get an impact wrench (found an electric at a pawn shop for $65 and it works great on suspension parts), 3) get a ball joint press (NAPA, also works great. Makes FWD easy).

Greg

thanks Greg. I'm gonna get a ball joint press from harbor freight, but an impact wrench is a big investment for me; I'll see if I can borrow one instead. Now what do you mean by checking what I have for toe in? Do you mean measuring the tie rod from lock nut to flat, or do you mean making a measurement from locknot to lock nut along the length of the steering rack and tie rods?

Toe in tells you how much the front tires are pointed together. It makes the car more stable running down the road. To get an idea of the toe in you measure the distance betweeen the center of the front tires at the front and at the back.

Toe in measured at the center of the tread should be 1/8" +/- 1/16". Measured at the inside edge of the wheel rim it should be 1/16". Measuring the rims is easier than finding the center of the tires. The front edge of the front rims should be 1/16" closer together than the back edge. If you find it easier to measure the angle for some reason, it is 16 minutes +/- 8'.

Since I had the manual out, under troubleshooting, front end shimmy or vibration, it says:

a. unbalanced wheels/tire or front wheels out of alignment
b. loose wheel lug nuts
c. bent rim
d. worn or binding front end parts or tires out of round
e. severly worn shock absorbers
f. worn control arm bushings

Greg

A ball joint press is not needed to replace the ball joints on a 240. However, an impact wrench likely will be.
--
1966 122s, 1968 142s, 1969 144s, 1979 245dl, 1989 244gl

I use mine for everything including tie rod ends. I have a collection of sacrificial nuts to protect the threads.

Greg