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B280
Member
Date registered: Jun 2006
Location: Vancouver,B.C.
Vehicle(s): 1986 280ge
Posts: 40
| Disturbing grinding.
Hello all,
I was wondering if anyone could give me their best guesstimate on what might be wrong.
The problem has only come up twice on my 86 280, both times after long distance driving. The last time was after about a 2hr drive from Vancouver to Seattle. When I finally came off the highway and was pulling into a parking lot there was a grinding sound. It happened at slow speeds when I was turning. I looked under the truck as best I could(dressed for a trade show) but couldn't see anything visibly wrong. I was busy for about five hours and when I drove off the sound was gone.
Now I'm guessing it's heat related because of the driving times and speed. Being a 4spd auto I rarely got above 110kmh. The first time this happened I drove my truck straight to my mechanic and it sat over the weekend. I told him I thought it might have been wheel bearings but he said they were fine but my shocks were done, two of them broken. The sound this second time was exactly the same and definitely doesn't sound like it's coming from the bearings.
Coming home from Seattle I was a little more cautious not wanting to have it happen again, but I did stay at about the speed limit. We also stopped halfway for a bit so when I got home there was no noise.
Enough rambling. If anyone has an idea would be greatly appreciated. I will of course eventually go to the mechanic but in the meantime...
Thanks in advance.
Biski. |
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DUTCH
Administrator Doppelgänger
Date registered: Apr 2006
Location: US, GA, Atlanta
Vehicle(s): 2015 Audi Q7 3.0 TDI,2018 Sprinter
Posts: 9963
| RE: Disturbing grinding.
B280 - 8/28/2006 1:48 PM
Hello all,
I was wondering if anyone could give me their best guesstimate on what might be wrong.
The problem has only come up twice on my 86 280, both times after long distance driving. The last time was after about a 2hr drive from Vancouver to Seattle. When I finally came off the highway and was pulling into a parking lot there was a grinding sound. It happened at slow speeds when I was turning.
Biski.
Grinding or a click- click - click ? If the latter, it's probably CV joints.
How many miles on your truck; and please complete your "My Profile" to tell us where you arre and what you drive. Thanks. |
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B280
Member
Date registered: Jun 2006
Location: Vancouver,B.C.
Vehicle(s): 1986 280ge
Posts: 40
| RE: Disturbing grinding.
Thanks Dutch,
I've filled out the profile and my truck's odometer say's 91,000. Now I think it's rolled but my mechanic thinks it hasn't. I was told the two owners in Germany didn't drive it that much, and I got it a year after it came to Canada.
As for the noise my memory is a little fuzzy as to what the exact noise was. Perhaps a slight grinding click. Pretty much useless I know.
Would CV joints make noise only after an extended drive?
Thanks again. |
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Brent
Expert
Date registered: Apr 2006
Location: SW Colorado USA
Vehicle(s): '13 Wolfsburg GTI
Posts: 1754
| RE: Disturbing grinding.
If your mechanic checked the wheel bearings I think the CV or CV's in front have gone bad on you. It is possible that the joints would make more noise after a long drive. The grease in the swivel ball is fairly thick and might mask the noise until it was thinned out by the heat of driving. The dead giveaway of a bad CV is clicking while turning. To really check you need to engage the 4wd, not the lockers but just 4wd and make some turns in a parking lot. Give it a little gas when doing so, see if the noise is there. If the CVs are bad, you will hear them.
Do not go out and try to do full power donuts on pavement in 4wd, you will definately have something broken after that. 
Next, plan on doing the wheel bearings while you have it apart. Then, you do not have to buy a whole axle shaft to replace the CV's, they are available seperately. |
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-UG-
Extreme Veteran
Date registered: Jun 2006
Location: Finland
Vehicle(s): GD300, S350 CDI
Posts: 446
| Re: Disturbing grinding.
I doubt that cv's would cause grinding noise or anything that would appear as grinding. Sources for grinding noise could be anything in the brakes (bad distorted disk, worn pads, something between the two, etc.) or loose (or bad) wheel bearings.
I once had my brakes totally stuck (in the braking position) on front wheels after a long drive. The only way I was able to loosen the wheel to continue my trip was to release the brake fluid by opening the valves that are used to let air out of the brakesystem (sorry don't know the proper term for those 'bolts').
I still don't know exactly why and I ended up replacing practically everything for the brakes in front. However, those problems happened during a really cold winter and may have been e.g. due to water or air in the brake fluid etc.
-UG- |
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AlanMcR
Expert
Date registered: Apr 2006
Location: US, CA, Los Altos
Vehicle(s): G300DT E300DT 230SL
Posts: 3500
| ... stuck brakes
Stuck / dragging brakes are generally caused by:
(common): internally swollen flex lines (happened to me);
(common) stuck calipers (rust/grit);
(rare) contamination in the master cylinder that plugs the return vent.
-edit-
-UG-
Your truck was probably suffering from the swollen flex lines. They look just fine on the outside, but chemical deterioration causes the inside lining to swell and seal off the flow. With the aid of the master cylinder you can still press fluid past the blockage. The return path holds enough pressure to lock the brakes. I got to fix this in the middle of an intersection once (on the 230SL). Flex hoses should be replaced every 10-15 years.
Edited by AlanMcR 8/29/2006 1:48 AM
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dai
Expert
Date registered: Apr 2006
Location: Oregon USA
Vehicle(s): 300GD 300TD BMW R100RS Landini 80F
Posts: 2110
| Re: Disturbing grinding.
Is the grinding noise coming from the front or rear?
In the front it is possible that a stone is lodged in the caliper and is striking the rotor. This has happened to me with front disks.
If it is coming from the rear try removing the wheels and brake drums and see if there is metal to metal contact in there. Could be a problem with a spring or a bent backing plate contacting the drum.
-Dai |
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B280
Member
Date registered: Jun 2006
Location: Vancouver,B.C.
Vehicle(s): 1986 280ge
Posts: 40
| RE: Disturbing grinding.
As far as I could tell the noise was coming from the front half of the vehicle. Again, like I said the noise disappeared after the truck had sat for a while.
I crawled under the truck yesterday to see if I could see any excessive signs of wear or if there was perhaps anything that would expand with heat and knock on a moving part, but nothing.
Now I'm pretty sure it wasn't the brakes. I don't recall the noise during breaking specifically. The noise happened once last summer and once this summer, with nothing in between. I'm going to try doing some turns in a parking lot in 4wd and see what happens.
Thanks again for your suggestions, they're really appreciated.
Biski. |
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dai
Expert
Date registered: Apr 2006
Location: Oregon USA
Vehicle(s): 300GD 300TD BMW R100RS Landini 80F
Posts: 2110
| Re: Disturbing grinding.
You can double check the front wheel bearings yourself. Lift a wheel off the ground (or entire front end) with a jack and support it with jackstands. Grab the wheel top and bottom and apply some force at the top and then the bottom. Pull at the top and push at the bottom and vice versa. There should be no movement. If there is any movement or clicking as you test them you have loose front wheel bearings and that is likely a contributor to your problem. Do not run long with loose bearings or you risk very expensive broken parts in addition to the bearings and seals. Some mechanics unfamiliar with the G will accept some play as normal. These bearings need a tiny bit of preload to live a long life and if they are loose they will die an early death and take out hub parts and possibly other things if allowed to seriously come apart. Check out Dave Gomes' great tech article on Clubgwagen. Loose hubs will allow the brake rotor to be affected by cornering forces.
If your noise occurs during hard cornering angles could your tires be contacting something?
-Dai |
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Adoni
Expert
Date registered: Apr 2006
Location: Sacramento, CA
Vehicle(s): '00 G500, '15 C300 4Matic, '06 L322 G4
Posts: 1283
| Re: Disturbing grinding.
Any chance you have oversized tires and what you are hearing is the tires rubbing when you turn? |
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B280
Member
Date registered: Jun 2006
Location: Vancouver,B.C.
Vehicle(s): 1986 280ge
Posts: 40
| RE: Disturbing grinding.
I don't have oversized tires so it's definitely not tire rub. I tried some turns with 4wd on and I couldn't hear anything. I thought I felt something but decided it was just the effect of driving on pavement with 4wd on.
I'll take it to mechanic soon anyway's and I'll have him do a thorough check. He's a German mechanic who specializes in German cars and even G wagens.
Thanks everyone.
Biski. |
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elevatorbernie
Expert
Date registered: Aug 2006
Location: Vancouver B.C. Canada
Vehicle(s): 1989 280GE
Posts: 1347
| RE: Disturbing grinding.
Sounds like you should get a second mechanic to look at it. The first nailed you for shocks that didn't solve your problem. Anyone can guess and change parts. Worn front end parts that cause noise should be easy to find. (unlike vibrations, looking for them is a garage's invatation to empty your pockets.) You could take it to mb for an estimate, no work though too much$$$. (pm me who the first garage was, I recently had a local garage here in Van. do some work on my G and tell me my shocks were shot too. I didn't change them yet, still work fine for street, no leaks or noise; just old. Maybe same place? |
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