Popping under my feet when steering - PeachParts Mercedes-Benz Forum

JHZR2 · #1 02-17-2004, 09:00 PM

Hi,

OK, first a bit of history... I had my car in at the dealer a while back, and they said they needed guide rod mounts. I got them from fastlane and had my MB only indy put them in.

Before this, I had a popping sound that originally was only in the cold when steering over a bump. Then I got one pop when steering sharply. Then worse, and worse.

I figured it had to do with the guide rod mounts. Thats why I urgently wanted to get them changed out.

I then changed to bilstein HDs myself last week. Havent driven much, but today I was out on a long drive... and the popping has gotten worse. It pops three or four times when doing a ~90 degree turn. And it now seems like it is coming from the floorboards area. I seem to feel it through the throttle when driving. I dont know if its a steering component thats binding up or doing something bad, or what else.

Any suggestions?

Thanks very much,

JMH

whunter · #2 02-17-2004, 09:21 PM

Hello JMH
Take it back to your MB only indy.
Sounds like they may not be installed correctly or you got a defective part.
Take the mechanic that will work on your car for a ride; so he will know exactly what you are talking about.
They may fix it under warranty.
Have a great day.

JHZR2 · #3 02-17-2004, 10:27 PM

Is there some way to test the guide rod mounts either visually or by force to see if they are bad, either in their installation or the part itself?

Doesnt seem to me that there is much to go wrong with the installation of these, Seems like a simple bolt off, bolt on, with the real issue being compressing he spring and removing it, etc. Similarly, I got febi/bilstein parts, I cant imagine they would be bad.

Any info on diagnosing these would be great. My indy is a good distance away (about 2 hours), so Id prefer to know what the problem is before taking the time to go over there and wait for it to be fixed, etc.

Thanks,

JMH

JHZR2 · #4 02-17-2004, 10:33 PM

And here's another one... Should the car be aligned when these mounts are replaced? I didnt have it done, but maybe I ought to... Perhaps there is too much slack in the guide rods, etc?

JMH

whunter · #5 02-17-2004, 10:49 PM

Gasp; must align after install......

Quote:

Originally posted by JHZR2
And here's another one... Should the car be aligned when these mounts are replaced? I didnt have it done, but maybe I ought to... Perhaps there is too much slack in the guide rods, etc?

JMH

Antony · #6 02-18-2004, 07:22 AM

I'm not too sure what the "guide rod's" to which you refer are; I encountered a similar condition when I broke one of the anti sway bar mounts on a really cold day.
The problem only surfaced when turning, and your description sounds similar to what I was experiencing.

adamb · #7 02-18-2004, 08:29 AM

It possibly could be the front rubber bushings attaching the guid rod mount to the ower control arm. Or, the most likey thing I think at this point would be the ball joint on that side. I have only seen ball joints last about 80-120k before they really show signs of wear.
I would also definitely get it aligned, but only after you find what the popping is and fix that as it's likely you'll have to tear down soem steering/ suspension components to fix.
Have fun, let us know what it is.
Adam

Eric Eliel · #8 02-18-2004, 12:28 PM

The guide rod controls the front to back movement of the lower control arm while under braking and acceleration. The guide rod mount is connected to the LCA and to the frame of the car. A proper installation of guide rod mounts would include an alignment.

The mounting point of the guide rod to the frame of the car should also be inspected. This is an area subject to cracking of the welded connection point. I had to have this done on my previous 300D. The crack will make noise similar to what you are describing.

If the frame connectors are securely welded, there are numerous other points that the can make noise on the front end of the 123 and 126 chassis. Sometimes you need to get the car onto an alignment rack and find a really good front end guy that will take the time to diagnois the noise and condition of the front end.

The LCA bushings get a fair amount of abuse on these cars and can be overlooked if the alignment guy is not an MB specialist.

JHZR2 · #9 02-18-2004, 02:54 PM

OK, heres an update...

Drove it in a bunch of conditions, found that I get 6 pops when doing a 90 degree turn. Turning left makes it happen more often, turning while driving backwards it doesnt happen at all. Accelleration/braking witht he wheels straight doesnt cause any popping sound either. With the car stationary, turning the wheel all theway side to side does not cause it to occur at all.

Took it to an mb mechanic to have him look at it. We drove it out, got the popping sound to happen, but when he had a look around (all his lifts were in use and I didnt have time to wait), he said that all the ball joints looked fine.

I got under the car and looked around, and shook stuff.
The guide rod mounts arein there fine. I looked at the back of them, where the bolts go through the car and to the mounts... Everything was fine; no evidence of cracks in the metal, etc. I yanked on the guide rods in every which way, but they didnt move at all, no play. I yanked the sway bar around, and it was fine as well. Same with the tie rods, no play. So it at least appears that everything under there is tight. I have to wonder if its something thats connected to the steering components down by my feet, since it is apparently steering related.

So thats all for now. Any comments or info based upon my findings would be really great.

Thanks,

JMH

adamb · #10 02-18-2004, 04:35 PM

I really would try to get the front end off the ground and get someone to turn the wheel back and forth at full rotation in addition to jerking movement left and right.
With the wheel off the ground you can really tell a lot, especially the ball joint which can't really be diagnosed accurately unless the wheel is off the ground unless it is really bad. I myself am leaning towards ball joints as they are the weakest link in our suspension system and cause a myriad of problems if not replaced.
Good luck,
Adam

JHZR2 · #11 02-18-2004, 08:33 PM

OK, another question...

I have found the following pic on ************************, and I will use it for reference.

I had the guide rod mounts that attach to the frame done (#20).
The indy I took it to didnt say anyhting about the front mounts where it attaches to the lower control arm (#22). they werent replaced.

Right now I am leaning towards it being the lower ball joints. Ill have it up tomorow to look for play in anything under there.

But was it really dumb for me to not do the bushings where the guide rod attaches to the LCA? Is this something I can do with the rest of the suspension still together? It looks like that bushing and the attachment between the LCA and the guide rod is just a bolt in the bushing. I suppose getting the guide rod out is the big problem. But can it be done without compressing the spring, etc?

If it turns out my balljoints are bad, should I have those bushings done at the same time? What else should I have done if the ball joints are bad?

Thanks,

JMH

[IMG]http://assets.************************/assets/bitmaps/38.gif[/IMG]

MikeTangas · #12 02-18-2004, 09:17 PM

When I did my guide rod mounts I mentioned cleaning out the mount recesses in the bearing brackets, Steve Brotherton relayed a little first hand knowledge about this. He told of cleaning all of the corrosion (from the old mount case) out of the brackets once, inadvertanly changing the dimension of the recess and have the new mount thunk just like the old worn mounts did. Problem was the mounts were slopping in the bracket. Remedy now becomes replacement of the bearing brackets - an expensive proposition.

Perchance did your indy clean out the brackets a little too good?

JHZR2 · #13 02-18-2004, 10:00 PM

ugh, that would really suck... But yanking on them with all my might doesnt show any movement of the mounts. But thats with the wheel on the ground. Ill take it up and check tomorrow... I hope this cleaning situation isnt it though.

One other tidbit of info: My front tires wear on the outside front edge of the tread lugs on the left side. On the right side, the tire wears on the outside rear edge of the tread lug, but the lugs are angled the opposite way on the other side. The car has always done this to the tires I have on (Dunlop SP Sport A2), and this is the second set Ive had on the car. I get the car aligned religiously (except for this time when I replaced the guide rod to frame mounts), at least every 6 months, if not more often. It seems that the car diesnt stay in alignment too well... But Ive never been diagnosed, even by the dealer who likes to sell parts, with a bad balljoint, etc.

JMH

shane83SD · #14 02-19-2004, 02:34 AM

My 83SD exhibits the poping symptom quite similar to yours. Left turn cause it to pop more. I jacked up the car and jerked on the steering wheel. I think the steering gear box is worn, and has quite a bit back lash. The steering shaft linkage is tight, so are the box to frame bolts. Time for a new box?

JHZR2 · #15 02-26-2004, 11:20 PM

It is all better, everything is tight now...

Turned out the ball joints werent that great (though boots were all fine), and the right tie rod had some play; so the whole assembly was changed. No popping now, and Ill hae it aligned tomorrow.

Would bad ball joints cause me to go through tie rods? Ive replaced three tie rods now (at least two were on the same side) in the last 50k. My tires also wear a bit more on the leading edge of the outside tread lugs. Hopefully now with a tight suspension, that will go away. I can get the mileage rating out of 40k mile tires, but they do show some funny wear between rotations.

Thanks for all the help.

JMH