A subframe question (just the beginning ...) - Page 14 - PeachParts Mercedes-Benz Forum

babymog · #**196** 02-08-2011, 10:59 AM

Is there play in the steering box? It is adjustable.

Do a simple test of the toe: Line up the tire on one side visually with the rear tire; so that you can sight across the tire surface on the front one and see that it lines up perfectly with the surface of the rear one. Now look at the front tire on the other side. Does the other side line up with the rear? Is it slightly outside of the rear tire (very slightly is good IMO)? Or is the sight-line hitting the rear tire (bad)?

You can do the same with the rear tires looking forward, IIRC the front and rear track are the same. The toe in the rear should appear to be zero, the front with no spreader bar should be very slightly toed-in, almost impossible to see.

This is provided you have no bent rims and the car has rolled into its parking place (not just lowered from a jack) also.

BodhiBenz1987 · #**197** 02-08-2011, 09:24 PM

I evened up the tire pressure, but didn't have time to do the test you described babymog. I'll try when I get home from work tonight.
I'm taking it to the mechanic tomorrow. He said he'll double check the alignment and check for anything out of place. I'm hoping he finds something that we can fix ... otherwise what am I going to, take it all back out and try again? I'm starting to think I should have just welded the crack in the old one and used it, because who knows if the replacement I used was straight?
To add to it all I noticed a creak (almost a tick) come from the rear when I got out of the car this evening, though I can't duplicate it now.
My spirits have completely sunken. I've tried for two years to get this car back to what it was when I first got it, and I keep making it worse. I know most people wouldn't even try, but I really want my car to last forever and it feels like I can't help it get there.

babymog · #**198** 02-08-2011, 09:33 PM

It'll get there.

Now that you have a solid start, it's just tweaking.

vstech · #**199** 02-09-2011, 10:41 AM

Oh no, don't be despondent! it'll get there. it could just be the rubber settling into place. you've put some miles on it now, an additional alignment could be just what it needs!
it's also possible that the subframe was not EXACTLY in position when you tightened up the bolts. if the alignment does not clear it up, see if you can loosen the bolts then retighten them in your garage without lifting the car...

Stretch · #**200** 02-09-2011, 01:58 PM

Quote:

Originally Posted by vstech

Oh no, don't be despondent! it'll get there...

X2 Yes come on you've got light at the end of your tunnel!

EDIT:-

I know this is written for a W123 but you can do a lot to check your own alignment:-

How I adjusted the toe in / out, camber and caster on my W123 300D

The secret's in the string and the slip plates!

Fulcrum525 · #**201** 02-09-2011, 01:58 PM

It looks to me like the positives outweigh the negatives so something certainly was accomplished!

Just a little more tweaking and i'm sure you'll get it!

gsxr · #**202** 02-09-2011, 02:47 PM

I would highly suspect the alignment as the cause if it wasn't done at the dealership. Ask if they used a spreader bar when setting the toe. If not, or if they tell you a story about how they don't need it, or can compensate for it... go to the dealer for another alignment. If that fixes it, I'd ask for a refund at the original shop. You'd be amazed at how much a slight error in toe can affect handling, exactly as you described.

BTW - the pressures you mention should not affect handling, but it wouldn't hurt to drop to ~32 all around (or, to MB specs listed in the fuel door). Tires can cause problems though even if they appear to be worn evenly. Only way to verify this is to swap on a different set of wheels/tires from another car which tracks normally.

BodhiBenz1987 · #**203** 02-14-2011, 06:58 PM

Quick, not-very-exciting update: Bodhi is still with my mechanic. I left it with him over the weekend so he could drive it a bit, look it over and give me his opinion. When I called this morning I talked to one of his assistants and he relayed that my mechanic had not found anything wrong, but he did think it wandered a little. He said he wants to keep it for another day to try something. So, I'm glad he didn't find anything terribly wrong, but on the other hand frustrated not to have an answer.
Of course if I know nothing major is wrong, I can proceed with tweaking when I get it back. I'll be interested to hear all my mechanic's thoughts though.

BodhiBenz1987 · #**204** 02-21-2011, 11:59 PM

Fairly positive update: I got the car back from my mechanic today after he drove it and studied it quite a bit. His take was this: He does not think there's anything wrong with the way it drives, but understands that a car's regular driver can be bothered by subtle differences that someone else isn't going to detect. And he says it is most likely my new tires. He pointed out that my BF Goodrich's are very flat-surfaced tires and that's probably why I feel like the car is less steady on the highway than it once was (actually the last tires weren't great either, but there was so much wrong with the suspension then I wouldn't have noticed). He didn't think they're a bad tire, but that he wouldn't recommend them on the w124 for the best handling. Like I said, the wandering/unsteadiness is pretty subtle, but seeing as I've driven this car so much (and to be honest also because I was so paranoid after this project), it was noticeable to me. He did check the alignment (even though he thinks it does not drive like a misaligned car), as well as inspect my handiwork. On a positive note, he was extremely complimentary about the quality of my subframe job ... he said when he had it up on the lift he was showing it to everyone and pointed out to them all that work was done by a girl.

He did also point out that the car accelerates beautifully straight and cornered well on the back roads, both of which I agree with, and those are good signs.
Anyhow, when the snow (again, really?!) goes away I'll drive it for a while with a fresh mind-set (i.e., not terrified that I put something in backwards or forgot a part) and see how it feels. Unfortunately I can't really undo the tire decision ... they're not so terrible that I can justify another $400-600 to replace them. I think next time I need new tires I'll do my research and spend more to maximize my ride.
So, to sum up, I'm guessing some of it was in my head and some of it is in my tires. But I can always tinker more.

JimmyL · #**205** 02-22-2011, 12:41 AM

Further proof that you really nailed this project. Very impressive work C!!!!!
Now for Chase..........

Fulcrum525 · #**206** 02-22-2011, 01:01 AM

Quote:

Originally Posted by BodhiBenz1987

Unfortunately I can't really undo the tire decision ... they're not so terrible that I can justify another $400-600 to replace them. I think next time I need new tires I'll do my research and spend more to maximize my ride.

Michelin MXV4s

gsxr · #**207** 02-22-2011, 03:24 PM

Quote:

Originally Posted by BodhiBenz1987

Fairly positive update: I got the car back from my mechanic today after he drove it and studied it quite a bit. His take was this: .... he says it is most likely my new tires.

'Scuse my French, but I call "bullpucky" on that. Brand new tires causing the problem? I seriously doubt it. At the risk of repeating myself, I would strongly recommending having the car aligned at a MERCEDES DEALERSHIP, nowhere else. Request the before & after printout which will look like this - you want "all green" for the "after" section.

Quote:

Originally Posted by BodhiBenz1987

So, to sum up, I'm guessing some of it was in my head and some of it is in my tires.

I'll bet it's neither, and that there is something fishy with the alignment; specifically front or rear toe (or both). $100 for a dealer alignment is way cheaper than ~$500 for new tires that you most likely don't need. The black 300D that I sold recently also didn't feel right, it "wandered" slightly at speed (hard to describe). I had to constantly make small corrections at the steering wheel, and it was worse in windy weather. The dealer alignment cured the problem, but what was interesting was how little the car was out of spec... it was a tiny amount of toe, IIRC. I'll see if I can scan that printout and upload it so you can see for yourself.

babymog · #**208** 02-22-2011, 03:45 PM

I've run my 124s on many tires since I bought most of them used. The original tires IIRC on my '91 were Michelins, I've also had Continentals (OE on the early 124s), Goodyear, and some Chinese junk (all replaced with Michelins).

Where I will strongly agree that good tires will make the car handle and ride better, none of these tires caused my cars to wander. If all is tight and right in the suspension, I'd love to inspect it visually, as mentioned in one of my earlier postings on the subject, and suggest changes as necessary. The alignment printout is useful, but if the spreader bar isn't used, ... the printout is not accurate.

Are the tires and wheels the correct size & offset? This also can cause wandering as the steering offset is affected, ride height will also affect alignment.

If the steering box hasn't been touched, it might be worth the effort to adjust any play out of it also.

Once the snow is gone and our cars can go out and play again, we need a midwest get-together.

BodhiBenz1987 · #**209** 02-22-2011, 04:51 PM

Quote:

Originally Posted by gsxr

'Scuse my French, but I call "bullpucky" on that. Brand new tires causing the problem? I seriously doubt it. At the risk of repeating myself, I would strongly recommending having the car aligned at a MERCEDES DEALERSHIP, nowhere else. Request the before & after printout which will look like this - you want "all green" for the "after" section.

He wasn't saying that they were causing a problem, but that they were causing the car to have a different "feel," which I was noticing. It's certainly possible he just missed something, but it's not like he was trying to sell me new tires or con me into something (he didn't charge me for anything) ... I'm just clarifying I don't think he was trying to BS me. That said, if you guys think I should doublecheck, I should probably doublecheck. Maybe this is a dumb question, but if it goes to the dealer and the alignment is already correct, do they still charge you the full price? I.e., can they just check it?
And yes, it'd be great if you guys could take a look or a drive.

I kind of feel conflicted because obviously I respect everyone's expertise here (I wouldn't have finished the project without it, and I know you guys have a heck of a lot more experience than I do), but I also respect my mechanic's expertise (he's been at this for some 40 years, and played a large role in the fact that this car is still on the road), and no matter what I do I feel like I'll be disrespecting someone's advice.

It would be an easier choice if the car felt horrid, but it just feels ... different. And I know I'm losing a little in translation as I try to describe it.
I guess it would be best to just take it to the dealer as recommended. Hopefully they won't wonder why I didn't follow their last bit of advice about my car:

babymog, the steering play has never been adjusted AFAIK, though I can thumb through the records to check. That may be a good idea too. Will search for the procedure tonight.

To share a positive thought, I can't get over how quiet and smooth the car is on shifts and when accelerating ... I still instinctively brace for the thunks and clunks and they don't happen. And I'm sure it's partially because I've been driving the 240D instead the past few months, but the 300D is such a missile when I want to pass people on the highway.

gsxr · #**210** 02-22-2011, 06:14 PM

You could always chat with the dealer service advisor and see if they'll give you a price break if everything checks out perfect, but I doubt it, unless they're really super nice. A good portion of the alignment time is getting the car on the rack and all the wheel sensors attached. If it all checks out, your longtime mechanic is exhonerated. If not, you (hopefully) solved the problem.

Steering box - I've yet to find a 124 steering box that had enough play to require adjustment. That was SOP (standard operating procedure) with the older steering boxes (123, probably 126/107 also) but the 124/129/201 boxes are almost always nice & tight. The usual 124 problem is leaking! If the steering shock is not recent, btw, check that out... unbolt one end and try to push it in & out by hand. It should take significant muscle to move it in & out with no "play" before there is resistance. If you can push it around like a slide whistle, worse yet with only one hand, it's probably toast. Don't expect magic results with a new steering shock but it's worth looking into.

See attached PDF of my alignment on the black '87 300D. Note that the only things out of spec were front steer ahead (very slightly out) and rear total toe (moderately out). Everything else was ok. And that little bit was enough for even my wife to notice while driving the car. This is why I say that the alignment is so critical... I don't know if the indy alignment guys even check things like steer ahead or rear total toe. (?)

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