vibration damper on driveshaft- buy 2nd hand?

Hi,
When my gearbox was replaced, the new one was put in without a "torsional vibration damper" (part #3 here) and they used washers as a spacer instead. I'm looking into getting it fixed the proper way. Can I get a used one from a wrecker or is it something that should be replaced with a new one?

Just out of curiosity, what is it made of? Metal? Rubber? How does it work?

Thanks,
Simon

yes, you can buy it as a used part. Some people, especially in racing applications, purposely remove it....

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nomis3613
Just out of curiosity, what is it made of? Metal? Rubber?

If it's like mine, the answer is both. Mine consisted of a disc on the vertical plane that is what attached to the driveshaft with bolts, and had a 2 inch ring surrounding it whos surface fell on the horizontal plane. These two were attached with some sort of solid rubber silicone stuff. The two attached pieces are what you are looking at in the diagram as #3. Or close, as I have yet to find a diagram that shows every piece of my setup without extras. I think I have a mutant Frankenstein year.

If you get a used one, and it's the same as my setup, make sure that rubber is still in good condition, as mine was so bad I could almost pull the two pieces apart with my hand, but instead opted to use a 5 year old knife I picked up in Costa Rica for $5. It's about as sharp as a butter knife.

[w3.gorge.net]
You don't want to get a used one that can be taken apart like mine was

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nomis3613
How does it work?

Mine doesn't :-)

Unless you think you are getting vibration from the drive shaft, I'm not sure why you would want to put one back on? I've head a few stories on the internet of people not bothering with it, and I don't think I will when I put my new drive shaft in. However if it becomes as degraded as mine was, it seems it could actually cause vibration instead of dampening anything.

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1989 - E30 - M20 - Manual. Approximately 270,000 miles
2000 - E46 - M52TUB28 - Manual. Approximately 110,000 miles

Thanks heaps guys. My car has a slight tremor at 40km/h, which is why I'm looking to un-Frankenstein my drivetrain!

Thanks for the pics and the advice, it was really helpful!

Very interesting thread! I recently replaced the rear muffler on my '90 325i because it had rotted out. After fitting the new unit and checking for leakage, I was surprised when the car sounded very loud at highway speed.At first, I thought it was the exhaust system - what did a screw up now? But stepping on the clutch at 65 mph and reving the engine produced NO excessive exhaust noise. Also noticed that the noise diminished significantly when the car was running on level ground or was coasting. Open the windows, and while you can hear the exhaust note (I like that), the noise in the cabin goes away.

Jacked the car up to check the Guibo and found the area sprayed with a red substance that appeared to be coming from the outer joint of the flex coupling. Also, I could almost pull the outer steel band away from the remainder of the flex unit, which is bolted to the drive shaft.

So, could this Guibo be shot? And would it be causing my noise/vibration?

Your most enlightened thoughts will be greatly appreciated.

Hi,
Sorry I don't know much about driveshafts, hopefully someone more useful will come along soon to help! In the meantime, here's some things to look for...

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Rosie158
After fitting the new unit and checking for leakage, I was surprised when the car sounded very loud at highway speed.At first, I thought it was the exhaust system - what did a screw up now? But stepping on the clutch at 65 mph and reving the engine produced NO excessive exhaust noise.

Could be an exhaust mount. Are they all hung properly on the rubber buffers? If something is attached to the chassis without rubber isolation, it will transmit noise into the cabin.

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Rosie158
Jacked the car up to check the Guibo and found the area sprayed with a red substance that appeared to be coming from the outer joint of the flex coupling.

Red fluid sounds like tranny oil from the output seal. Would you have noticed if the red was there before the muffler swap? Did you move the driveshaft when replacing the muffler (yeah, I don't know much about these things), maybe the output seal is worn and moving things around made it leak.

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Rosie158
So, could this Guibo be shot? And would it be causing my noise/vibration?

See [www.bmw.e30tuner.com] and [e30world.com] for if the guibo is stuffed. If the noise is a "thrumming" sound and changes heaps according to speed, then the driveshaft is out of balance. From what I hear, it's easy to upset the balance of them, eg as little as using bolts that are not the same weight or not tightening to the correct torque. I spose a stuffed guibo could possibly cause the unbalance (even though it's not mentioned in the articles), but the coincidence of it happening at exactly the same time as you change the muffler is very unlikely!

Hope this helps,
Simon



Edited 1 time(s). Last edit at 05/01/2010 05:43PM by nomis3613.

Thanks for the input(s). My first thoughts on the red stuff around the Guibo was trans fluid. But I checked the area around the output shaft and it was dry. The red stuff was coming out of the circumferential joint at the outside of the Guibo. The driveshaft had not been disturbed during the replacement of the muffler and as far as I can remember, the noise was not there before the muffler was changed. However, the noise from the leaking muffler could have been masking the "Thrumpping" noise that I now have. And, thanks Simon for naming the noise - Thrumming is a very good description. I would venture a guess that a lot of people have this problem. The noise is not overly objectionable - especially if the windows are open. And, the noise could be mistaken as just the "Sporty" sound of the BMW 6 cylinder engine.

Well, I"ll jack-up the car and drop the drive shaft. We'll see what we have at that point.

Paul R.
'

Glad I could help!

Yeah, I reckon the thrumming has always been there, whenever you fix a noise problem then you just hear the next noisiest thing. If it gets worse over time (or increases at high speed), definitely get it looked at. Otherwise you can just turn the stereo on and leave it until you're next poking around with driveshafts...