Just Bought '87 325e - Noise?Vibration? Please Advise

[NJGreenBudd]

Hey guys,

So I bought this 325e because it was in good physical shape and cheap. During the test drive I noticed it had a noise/vibration that develops around 30mph and gets louder as you go faster.

It kind of sounds like a tire rubbing on something but it's not, the wheels are solid and good wheel bearings. It definitely sounds like it's coming from the rear center of the car, possibly the differential or drive shaft? It's not a whining noise, it's more like a constant rumbling noise. It does not vary with rpm, only with speed.

Would it be possible for the drive shaft to cause something like this? Someone said to jack up the car and run it in gear with the wheels of the ground but that seems kinda dangerous, plus I don't have a partner to help. Is there some way to isolate the source of the noise?

I'd appreciate any input on this matter.

Thanks in advance.

-NJGB

[jlevie]

The way to isolate the noise is to put the car on a lift, get the wheels up to speed, and check the rear hubs and diff for noise. If the noise is present with the car on the lift and is isn't in the final drive, the cause will probably be a bad drive shaft. If the noise isn't present it will probably be from the tires.

[Dirty E thirty]

change dif fluid first, the put it on a lift to check the bearings. you should know if its a bearing right away while driving. the drive shaft is your best idea go from there.

[NJGreenBudd]

Okay, looks like I will have to run it up to speed with the wheels off. Is it safe to jack up the car from the rear subframe, like where it goes under the diff? Can I put the jack stands to the sides of the diff on the subframe and run it like that or would you recommend something else. I don't have access to a lift at this point.


Thanks for your input, I appreciate it a lot. This is the only problem with the cat and I want to get it fixed as soon as possible.

[jlevie]

You can lift the rear of the car by placing the jack under the differential. Place the jack stands under the subframe bushing locations. I personally won't get under a car that is on jack stands for this test. I'll only do it with the car on a lift. The risk is small, but there is a risk in doing it this way.

Given the nature of the problem, you would probably be better off to have an expert diagnose the noise anyway. Taking the car to a shop for diagnosis won't cost all that much.

[NJGreenBudd]

Okay, I'll let you know what I find out, hopefully I can do this tonight or tomorrow after work. Thanks again for the help here.

[Goya20]

Yea i had the same thing and it was bad U-Joints and center bearing, hope my input helps

[NJGreenBudd]

The more I am thinking about the symptoms I am leaning towards drive shaftrelated issue, not wheels or differential. I have had a few cars that had bad diffs and none of them sounded like this, all were higher pitched and changed with throttle input where as this is a rumbling that only varies with speed. I just remembered that the noise dissipates when you slow to a stop and you can hear it actually going round and round until a complete stop. When you start out it's quiet but by the time you hit 30mph it's a very pronounced rumble.

As far as replacing driveshaft, U-joints, center bearing goes, what exactly is involved in this? Are the U-joints separate from the shaft or all one piece? I have seen the center support bearing for sale cheap but have no idea about u joints or the actual driveshaft. Is there an option to just replace the u-joints or am I looking at a whole new shaft here?

Thanks to everyone who is contributing here, I am going to try to look at the condition of the driveshaft tonight when I get home.

[NJGreenBudd]

Update

So I just got this E30 and I like it but it needs some work. I got it up on jack stands today and took the wheels off to get a better look at things. Made a few discoveries along the way - the rear drivers wheel bearing is actually bad, all rear brakes are in horrible condition and the diff is weeping from the axle stubs. Also saw some fluid on the engine and trans, looks like from shifter. On a good note I found out the car has an LSD in it, very cool bonus.

Again, I have been trying to diagnose a bad rumbling vibration in the back above 30mph, I was thinking maybe driveshaft but these brakes look horribly worn and warped, plus the bad wheel bearing, could these be the cause of that noise I wonder. I'm going to be taking the exhaust off this weekend to redo the cat and muffler so I'll checkout the driveshaft at that point. Right now I am looking to install new pads and rotors for the front and rear, replace the bad wheel bearing and new seals in the differential.

What would I need to pull the wheel bearing out and replace it? I'm really just looking for input on these repairs, any useful tips, tricks or suggestions would be appreciated. Thanks.

The Car-


Engine Oil Leak-


Trans Leak-


General view of rear end-


Diff-


Brakes-

[NJGreenBudd]

Update

So I got all new rotors and pads today, plus my exhaust stuff got here. I just bought cheap high flow catalyst and magnaflow muffler, I had a spare exhaust tip laying around so I might weld that on too. I am picking up a rear wheel bearing in the morning, decided to get a start tonight and pull the axle.

New Parts yay!




Progress










So now I am at the part where I need to remove the hub, just not sure which is the best route for me here. I would prefer to do this in my own garage and have read/seen the hub driven out with a socket and hammer, 30mm I think it was foe the hub and 1.5" for the bearing. How do you get the new one in though without smashing it? I don't have a press handy at the moment.....

[NJGreenBudd]

Progress Continued Here:

http://www.r3vlimited.com/board/showthread.php?p=1654207#post1654207