If I forgot to...

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steve

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Grease the output shaft of the tranny when I put the driveshaft back in would it be making the chirping noise I'm hearing now after I drive around a while?

I thought at 1st the exhaust was hitting and I have been fooling around trying to adjust it. But if it was the exhaust it would do it all the time. And even though it close I dont think its hitting.
 
Do you mean bursts of high frequency chirping, or an occaisional, single, chirp? If both the male and female splines were completely unlubricated, then I would say prepare yourself for E30-ix level spline failure. However, if they were pretty well lubed up already, this seems unlikely. Ask Blumax how many drive shaft splines he's been through. High frequency chirping is often a characteristic noise associated with failing U-joints. Did you have these changed while the shaft was out? Exhaust: maybe one of the clamps, or downpipe bolts, is loose enough to hit a resonance at certain rpm?
 
I not talking about the splines from the tranny to the motor. I mean the where the driveshaft slides onto the output flange at the rear of the tranny.

It's more of a chirping / wha wha wha sound the gets faster with the speed increasing with the motor. Doesnt do it all the time. When I first take her out theres no noise. If I get her good and warmed up and lean on her it starts doing it.

Drive shaft was just rebuilt recently so its not the u joints. I just swapped out the tranny and everything was fine before the swap. The center resonator is pretty close to the drive shaft and I can see evidence that it has touched before. But I dont think it is now. If that was the case I would think it would be doing it all the time.
 
I can't see that the problem is at either end since the connections at the tranny and the diff are fixed points. Did you replace the centre bearing support? Check the rubber doughnut for tears if using the original? Did you give it the 1/8" preload towards the tranny? Is it dead on the centre line between the tranny and the diff?

All else fails, drop the centre and grease the splines and then check everything is right as you re- install.

Good luck.
 
Yup did all that. Let me ask this. The clearence is tight between the shaft and exhaust. So maybe that is my problem. There is like a 1/2 - 3/8" near the rear of the center resonator and it was hitting there which is evident by some marks on the driveshaft. But wouldnt it just be hitting all the time if that were the case?
 
From what words you are using to describe what you are hearing, in order from your crankshaft:

1) did you replace the center bearing in your crankshaft? Was it lubed? Was it ball bearings or roller ("needle") bearings? A lot of people use the later roller-bearing one, but I still prefer the ball bearing one. Either one will definitely make noise if dry, or worn. The ball bearings are more durable, but regardless of which you have if you did not replace it, it's likely the source of your noise.
2) did you replace the throwout bearing? Are you sure it is the correct t/o bearing for your application? did you lube the input shaft housing on your transmission (the one the throwout bearing slides back and forth on)? Is the throwout bearing proberly grease-packed? Are the clutch fork contact points on the throwout bearing and on the ball it pivots on lubed? These will also make noise if dry. If the center bearing in the cranshaft is good, then this is the source of your noise.
3) Did you replace the centering bearing on your driveshaft? Its the one that the output shaft of your transmission fits into. It is real important to use a new BMW bearing, and not one of those cheap, fiber or rubber ones that driveshaft rebuilders favor. Not only would a worn centering bearing be a possible (but not very likely) cause of your intermittent noise, but if it is not solid, the off-centerline play will contribute to short guibo or flex-plate life.
4) If you think there is contact between your exhaust and driveshaft, there will be signs of the contact ON your driveshaft and the adjacent point of the exhaust (rubbing)
5) be sure that the support bracket for the exhaust that bolts onto the back of your transmission has new rubber in the bolt bushings, again, use only BMW parts. If you don't HAVE a rear-of-the-transmission exhaust bracket, get one with all associated hardware new from BMW.

Hope this helps.
 
Chirp..

steve said:
Yup did all that. Let me ask this. The clearence is tight between the shaft and exhaust. So maybe that is my problem. There is like a 1/2 - 3/8" near the rear of the center resonator and it was hitting there which is evident by some marks on the driveshaft. But wouldnt it just be hitting all the time if that were the case?
Click to expand...

It's quite possible for the shaft to move that far and contact the exhaust under load. Remember, everything on the drivetrain is mounted on rubber and you'd be surprised how much stuff moves. Sometimes its tired or broken mounts someplace on the drivetrain, or in the case of my old Jaguar it was a cracked rear suspension housing that allowed the driveline to move way too much.

How about putting some tape around the driveshaft where you think its hitting, drive it and check to see if its marked.

Just to throw in a curve-ball to this problem, the last time I had a chirp in my '73 2002 it was the distributor rotor! Go figure.

Dan
 
here's what I did recently

Friend brought over the female unit's 2000 Suzuki Vitara which had a regular groaning noise that was speed dependent. None of the three of us could tell where it was coming from while in the car.

So we jacked up the car, put stands under all four corners, and ran it. Wheels off the ground. Crept under the back of the car (wheels spinning maybe 20 mph) and the diff was okay; got my ear next to the right rear wheel and AHA that's where the noise was coming from.

We deduced that a wheel bearing was failing. It was late on a Sunday afternoon, the diagnosis was delivered, a SWAG at the cost, and sent the two of them on their way. I have not the time, inclination nor slide hammer to pull the axle, and didn't have the parts anyway, little interest and no anticipated compensation for the diagnosis or the job. Sure enough, I got their thanks and off they went.

NOW LET ME CAUTION that getting under a running car is something you don't normally do. We took what precautions we could: level concrete surface, secure jackstands, car in a forward gear and climb under between the rear wheels, not between front and back. Well okay I did that too, when I felt the car wasn't going to get off the jackstands.

I DID THESE THINGS AT MY OWN RISK. I/you would be dead on the driveway if something went wrong. In retrospect, for some broad I didn't know, was it worth it? I get brag rights over the "mechanic" who couldn't find the noise but nothing else.
 
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