Given that all your symptoms seem to relate to front end and steering inputs have an effect, it's worth looking closely at the ball joints. It's very difficult to detect a small amount of wear when they are loaded. Next time it's in the air, is it possible to disconnect a control arm to get a better feel for ball joint health?
In reply to Ando :
The effect from steering got better when wae heated the brakes up a good amount, and I think may have gone away after the pad/caliper swap. If the driveshaft parts don't do the trick, that is likely to be the next place I search. Or I may go buy something else.
This frt end shimmy sure sounds like a slightly out of round wheel. A slightly worn bushing or TRE will not usually induce a vibration. An imperfect tire will create a vibe, and throwing a bunch of parts at it may change the perception of the vibe, but never eliminate the root cause.
Also, there's talk of driveshaft vibe and of wheel/bearing/rotor/halfshaft vibe. There is a crucial and noticeable difference: driveshaft vibe is approx 4 times higher frequency than wheel vibe. At 80MPH a tire vibe is a vigorous shimmy or thump. Drive line vibe is a buzz.
It's out.
Never allowed to be easy. There's a metal damper between the front flange and the giubo. It has little adapters/spacers to make everything fit right. They are stuck fast in the old giubo.
I'm going to step back and think about how to remove them without destroying them. Already tried prying, and started to try to twist them off before I got worried I'd break them. Hit them with some penetrating oil. Hopefully that helps.
In reply to eastsideTim :
Good luck!
Potential u-joint issue. Here's the thread if anyone has input.
Center support and bearing off now. Bearing has a little bit of play. At this point, going to hold off on reassembly until a verdict is in for the u-joint. I'm not doing this job twice.
Can't wait for the updates.
Still haven't come up with a way to remove the spacers on the front giubo that is not destructive. I did a part number search on the metal front damper, and pretty much nothing on it that isn't a foreign site. I am wondering if it was just not on all W211s. However, I did find another brand giubo that has those spacers on it, so I am also wondering if they are just not designed to be removed.
I also have a query in to a local driveshaft shop that is supposed to be really good, to see if they'll replace a staked u-joint.
I'm feeling like a berkeleying idiot right now. Down to less than a month and a half.
If replacing the u-joint (in a reasonable amount of time) is not a possibility, here seem to be my options:
Problem is, either one of the first two options only may solve the issue. If I go with 1, maybe it's the u joint that is the problem. If I go with 2, and it doesn't fix it, then I'm out more than $1200 that I can no way recover in the resale value of the car. With option 3, well, the future is murky, and who knows when I'll get another chance. With an elderly cat at home needing more care, I could soon be back to where I was a couple years ago with her brother, and not being able to be out of the house overnight.
Not to mention, I need time to put miles on the car to see if there are any other critical issues that need to be dealt with. I don't think there are, but it has spent so much time laid up in the garage that I can't know. And with the time I have left, I am of the opinion I don't have time to buy anything more than a 3-4 year old car and make sure it is alright at this point, and even that is shaky. If I buy a new car, I need some time to put some break in miles on it and get its first oil change.
This is feeling like one hell of a sunk cost fallacy. I think I am ordering the giubo and exhaust gasket, since I probably need them regardless, and letting the chips fall where they may on the u-joint. Between work and home life, motivation is hard to come by on weeknights, too, so weekends are pretty much my only somewhat reliable working times.
Isn't the u-joint just held in with snap rings? Can't you just remove it and take it to a shop to have them find the right replacement size? I thought u-joint replacements were relatively simply.
I say put the driveshaft back in and send it!
In reply to eastsideTim :
EDIT: not enough coffee;I see it's not a confident fix. I think the principle still mostly applies, but that's a big chunk for a maybe.
You've acquired an entire car for an event a long way from home, and time is short. If you're confident that the $1200 driveshaft will sort you out, I'd stop looking at it as a bad investment in the car's value and see it as a modest investment in travel insurance and getting to do an important event.
Jesse Ransom said:In reply to eastsideTim :
You've acquired an entire car for an event a long way from home, and time is short. If you're confident that the $1200 driveshaft will sort you out, I'd stop looking at it as a bad investment in the car's value and see it as a modest investment in travel insurance and getting to do an important event.
That's the problem - I am not confident the driveshaft will fix it. The more I read about vibration problems on these cars, the more it seems like throwing parts at it until it is fixed is all anyone can do, even the dealerships. There are still several possibilities, all of which could cost a few thousand more, and take more time to resolve. In the meantime, the car ends up sitting, so I can't put miles on it to see if there are any other issues that need to be dealt with.
Blunder, the u-joint is staked in place, so it is not supposed to be replaceable. Will see what the driveshaft shop has to say.
I also had a realization this morning - I didn't check the center bearing until after I removed it. It could have been fine until I damaged it with the puller.
I've ordered parts, and paid extra for quick delivery, so if I can muster the motivation, I can try to put humpty dumpty back together during the week.
EDIT: Another concern (beyond not being sure I'll be able to attempt this again for an unknown number of years), is this kind of dwarfs the challenge in cost. It's going to cost between 1.5-2 Challenge cars between entry fees, gas, and hotels, so I really want to reduce the risk of a DNF or worse yet, a DNS. Just more mental calculus going on in the background.
No dice on getting the u-joint replaced. Guess I'll throw everything back together when the parts come in and see what happens.
In reply to peanutpckrupper :
I didn't check car-part, but had jumped on eBay, My concern is mine might still be in better shape than a random used one, especially at the age they are now.
If I was certain the driveshaft was the issue, I'd have no problem dropping the $1200 to get a factory one, so a cheap junkyard one would not be a big deal to buy either, if I knew it'd work. Time is getting short, though, and just getting the car into a state where I can pull and replace the driveshaft is a decent amount of effort in my packed garage (not to mention arthritis and generally being out of shape for all this crawling under the car). It'd be a big time sink to swap in a junkyard one, find out it doesn't work, then put mine back in, and find out it also doesn't work, so I'd rather just do it once. I need to make sure I don't run the clock so far that I no longer have a workable contingency plan.
At this point, option 1 is the plan.
In reply to eastsideTim :
Can you at least get the driveshaft looked at or balanced? Maybe they can't replace the u-joint but maybe they have a way to tell if it's causing the vibration?
Blunder said:In reply to eastsideTim :
Can you at least get the driveshaft looked at or balanced? Maybe they can't replace the u-joint but maybe they have a way to tell if it's causing the vibration?
It may be possible, not sure how much it would cost. I have a (ancient) history of vibration analysis, and some of the things I've read up on these throw me off a bit. The driveshafts are apparently supposed to be assembled together in a specific way, but there is no indexing spline, so I am not sure if they are balanced when together or apart. If apart, I suspect I could take the rear section to a shop and have it balanced, and see how it does. If together, I'll need to reinstall the center bearing and support in order for it to be tested, and at that point, might as well put it back on the car and see what happens.
I am curious to see if I can find anything about what RPM various u-joints tend to vibrate the most at when they start to fail, based on driveshaft angles. The one on the car seems close in size to a 1310, so if I was willing to take a leap of faith, I could translate it over to the speed the car is going, and see if it is a likely candidate. I also have a hypothesis that the rubber in the center support starts to fail first, which then starts beating up the center bearing and u-joint, eventually taking them with it, and making the vibration worse and doing more damage to the rubber. If I'm lucky, I caught it early enough in the cycle. Of course, this is all also assuming the driveshaft is the source of the vibration. It is also possible that the driveshaft is contributing to the vibration, but is not the sole source, much like how the directional vibration went down/away when the brakes were exercised more, then replaced. I need to keep reminding myself there are several other potential sources.
Is it possible while the car is up on stands with the driveshaft out to put it in gear and give it some gas and see if the vibration is no longer there?
In reply to Blunder :
Yes-ish. I suspect I could put it back in dyno mode. Although it'd be hellaciously noisy with no mufflers. That could test the motor mounts, but I think they are okay.
Parts have arrived, and the new front flex disc looks correct. The kit I bought earlier came with driveshaft end bushings, which are supposed to help center the driveshaft. It appears most people don't change those out, they just re-grease them. The front one still had some grease in it, but the rear one is bone dry. Also, after a check against the new one, the opening on the rubber seal for each is bigger. So, at the very least the rear one should be replaced.
Looks like the FSM suggests trying to knock it loose with a chisel (yeah, that's going to work on one that has been in there for 14 years), and if that does not work, drill a hole in the bushing, run a drift pin through it, then lever it out with what look like a couple of tire irons. A little research online on some sites for older Mercedes is showing some people getting a good grip on it, and using a slide hammer.
My workbench vise is in kind of a bad position relative to the car right now, but I have another one I can clamp into my Workmate. My slide hammer was a victim of my storage fire earlier this year, so I think I'll try chisel method first, but will likely quickly move on to the drill and wedge method. I am hoping to get the motivation to work on this tomorrow after work, I figure this step could take a while, but after that, getting everything back together should not be too difficult.
Got the rear half of the driveshaft clamped up in the vice. Tried using vice grips to see if I can loosen it at all, but no dice.
Drilled a pilot hole:
Then a 3/8" hole all the way through:
Slipped a bolt in to pry against:
Made several attempts with several different tools, and the only thing I succeeded in doing was bending the bolt. Maybe a torch will help loosen it up, but I am a little too tired to play with fire tonight. I might also go and grab a replacement slide hammer tomorrow. I figure the newly drilled holes should provide something to grab onto.
Kind of tempted to just do the rear one, since the front still had grease left in it, so should not have any wear.
Ran to the hammer store this morning before work, and during lunch, tried the slide hammer (no dice), and two 18" pry bars (also no dice). Prying just bent the bolt more. I don't have any grade 8 3/8" bolts laying around, but I do have some 7/16" ones. May drill the hole out for them to fit. I suspect I am going to have to heat the bushing up with a torch, then try to pry it out. That is going to smell really bad when the plastic inside it melts, not to mention I better not wear sandals for that job. If anyone's got any suggestions, I am listening.
Drilled the hole out to 7/16", and tried to pry it. Didn't work, but it didn't bend the bolt this time. Heated it with the propane torch. Didn't work. Heated it with the MAPP torch. Didn't work, and actually distorted the bushing.
If I can't figure something out, I may end up having to buy a replacement driveshaft anyway.
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