280c Steering Woes - PeachParts Mercedes-Benz Forum

PaVarrieur · #1 11-04-2004, 01:31 PM

Hello everyone
New problem has come up with my 280c. The steering wheel started to make a slight "popping noise" when wheel is turned to the left. and recentered to the right. This went on for a day when it made a louder pop, and steering has become vague and loose. It is now also making a grinding noise that appears to be coming from the shaft. The slight popping noise is still there. Could this be the hyme joint for the steering shaft that is located at the firewall? It does not turn true. There does not appear to be anything wrong with the Idler arm, or ball joints etc. The noises appear to be coming from inside the car, and not from under it. Any one ever had a problem with the steering shaft hyme joint?

thanks

300SDog · #2 11-04-2004, 02:41 PM

Check the steering box mounting bolts in the wheel well too. They've been known to work lose and the holes rust out or the sheetmetal cracks.

WANT '71 280SEL · #3 11-04-2004, 07:00 PM

Steering couplingbushings. you may be lucky because I think you might be able to replace just the bushings instead of the whole piece. I just did it on my SD and it fixed the pop noise. I know it sounds like it's coming from inside the car, but it's not, believe me. Have someone turn the steering wheel around while you put your hand on the coupling and check for play. It is right above the box. I think I paid like $111 for the coupling. Be sure to mark it well so you get the new one on EXACTLY how the old one came off.
Thanks
David

Mark DiSilvestro · #4 11-05-2004, 11:41 AM

This was happening to me as one of the three steering box mounting bolts kept breaking and I kept replacing them until I figured out that my frame-rail had cracked and was flexing. Have someone turn the steering wheel back and forth, while you look under the hood to see if your steering box is rocking.

Happy Motoring, Mark

PaVarrieur · #5 11-05-2004, 06:53 PM

Mark
Which one of the bolts kept shearing off? How did you locate where the frame rail was cracked? After reading the posts, I have found the following: Upper Steering Box Bolt Sheared off, middle bolt missing, Lower bolt still there, but loose!!!!. The couple bushings are also bad. Do not see any cracking on or around the frame rail. If your frame rail being cracked was the cause of the steering box bolts breaking, did you repair the cracked frame rail, or call it a day and send the car to the salvage yard? I'm trying to decide if it is time to put this sky blue 280c out to pasture. I would hate to do it, but the repairs on this car are starting to get out of hand.
It also is in need of sub frame mounts, motor mounts, and control arm bushings.

dieseldiehard · #6 11-05-2004, 07:32 PM

This is a fairly common problem. Had that experience in my '76 W115.

I'll never forget the sound that the bolt made as it sheared off thec dropped (shot?) to the ground BANG...tinkle cling, then clunk as the steering box twisted free and hit the frame.
There is (or was) a modification kit that consisted of a heavy steel plate that went on the outward side of the frame, and it had (welded on to it) large cylindrical posts that went thru the frame and the bolts for the steering box went into them (they are internally threaded).
Unfortunately when I sold the car for scrap the kit went with it

I believe you could do about the same yourself with a steel plate, have it cut the same size as the frame, use new bolts thru it and into the steering box, sort of sandwiching the frame.
I will inquire around to see if any of my friends still have such a kit.
I am not certain if the retro kits were MB or aftermarket designed but its just unfortunate that the car wasn't designed better in this area.

My 220 is a W115 but it has manual steering, I am watching it though! I think the power steering is one factor in the weakness. Loose bolts might be another part of the reason it happens.

You might just have a internal bushing problem, I have heard that noise too, its just a light scratching sound as the steering wheel is rotated, no clunks like the broken bolt problem!

Mark DiSilvestro · #7 11-05-2004, 08:42 PM

In the case of my '72 W114 250 sedan, it was the upper 'long' steering box bolt that kept shearing off. I replaced it three times over the course of eight years, sometimes adding thick washers under the suspect bolt, until the fourth time, when I realized there was something else wrong. The last time it broke, the stub was seized in the steering box, so I had to drop the box and drill it out. In my case, the frame rail was cracked around the lower 'long' steering box bolt. I cut an access hole just back of the cracked lower bolt area and fished a couple of threaded plates further back inside my frame rail. I pop-riveted these in place for additional support for the reinforcing plate. Then I fabricated the plate from a 4" x 8" piece of 1/4 inch thick steel and added a tube, fashioned from a suitable piece of galvanised pipe, to insert into the recessed 'middle' bolt hole. so I could use long bolts for all of the steering box mounts. When I was finished, the reinforcing plate was bolted at the three steering box holes, plus the two additional holes and threaded plates that I added further back inside the frame rail. Secured with 5 bolts, the reinforcing plate bridges the weakened portion of the frame rail and prevents it from flexing.

There's a chance you might get lucky and your broken bolt could just be the result of the other two loosening, instead of a cracked frame rail. I suggest first, replacing the broken/missing bolts and tightening the other one, then doing the 'flex' test by watching the steering box for any movement while someone inside turns the wheel back and forth. Good luck.

Happy Motoring, Mark

dieseldiehard · #8 11-05-2004, 10:11 PM

I spoke with my friend that has the steering reinforcement kits I described.
If anyone is interested in one, send me PM and I'll put him in touch - or I may list them for him on the Parts Forum.
These will fit any W114 or W115 cars from about 1969 to 1976.
He hasn't said what he wants for them, probably after he digs them out he will set a price. Probably quite reasonable I am sure.

dieseldiehard · #9 01-22-2006, 05:46 PM

I sent Paul an Email, you've got first dibs on the MB kit for repairing the breaking bolts syndrome on 114/115 chassis cars. Paul?
I have this boxed up and ready to go if I don't get any response I will list on the parts Swap

Ten13 · #10 10-15-2018, 05:43 PM

I know this thread is very old, but I wanted to contribute to it with a photo of the repair kit my 1974 280 sedan came to me with. This is a low-mileage (73k), very well cared for california native car with absolutely NO rust issues. There is a distinct creaking sound, felt in the floorboard to the left of the brake pedal, when turning a slow-moving car. It's fine at speed.

While my car has this plate installed, I have also identified at least three broken spot welds just behind the plate. You can see, in the photo, evidence of the undercoating being cracked.

I will be removing all of this, cleaning the area, and putting a seam weld on the frame, and then reinstall the repair plate.