I just installed a 3,5" dynotech 1pc alu driveshaft. On my first testdrive I experienced quite some drone thru almost the entire rpm range. After a few miles most of it settled, but there is still a drone at 1800rpm in higher gears and at rpms above 3000 in lower gears.
Does anyone have the same or similar problems? Is that a known issue?
And another thing I noticed during installation, is that the dynotech shaft is a little shorter than the stock one!

Joe

 

Is it possible that the bolt holes on the driveshaft are to big? Could that be the source of the drone in my case? Any ideas?

 

Seems like there's a thread here somewhere that mentioned a vibration or some kind of issue. They unhooked it and reattached 180* and solved the problem. You might try search or just try it and see.

 

Here's one. He did a 90* turn but still has a bit of vibration:

https://themustangsource.com/f800/ds...3/#post6766505

 

Thanks, so I'll do the 90 degree turn and see what it does. On a driveshaft shop site I found a pic showing that there is a marking on the shaft and connecting plate and that they have to be aligned. Does anyone know?
Other than that I am going to measure the bolt hole on the stock shaft and the new one. If there is a noticeable difference I might try to eliminate that with some kind of stainless tube, if possible.

 

I just got back from readjusting the driveshaft, but didn't turn it at the gearbox. Instead I rotated the shaft at the differential. The point that I didn't notice the first time is the marking on the shaft and the flange, I aligned both and everything seems to be o.k. We will see after the next real testdrive, if it is quite now?!

 

 

good deal best of luck

 

i just threw mine in there and was done in 15 mins max. i didnt notice any markings. ive changed drive shafts in several vehicles without doing any markings and ive never had a problem with vibrations. maybe i just got lucky all those times but i figured they were all independently balanced. i dont see how the rearend/pinion could be balanced with the transmission though.

 

I have no idea what's wrong, maybe the transport to Germany was a little bit rough. There are no visible signs of damage, could there be a problem with the joints?
Or could it all settle after a little bit?

 

Does anyone know where to lubricate the u joints? Any pics available?

 

You don't lubricate u-joints these days. That's why there's no zirk fittings inside the X.

If the u-joints were installed without grease, they would be making noise by now. Often you hear the "ring the bell" sound as you slowly drive away or back up. This would be a broken needle bearing inside the u-joint and the crunch makes a single or double note bell ring sound from the hollow drive shaft.

Haven't you contacted where you bought it? Double check its the correct shaft or ask them about balance issues.

 

Actually I contacted the shop where I got it from and besides the advice to get it balanced, they recommended to lubricate the joints!?! Do you think it was trying to get around it the easy way?

 

I think everyone here that has installed one would say that's a line of bunk. They balance them off the vehicle and they should come pre-balanced. Not that they can't get dinged in shipping (which could throw them off) but you should be able to see that.
As for suggesting you drive the u-joints out, take the end caps off and re-grease them (keeping all the needle bearings in place while you do so), and reinstall the u-joints - all on a brand new expensive drive shaft is also a load of horse ****. And would void any hope of warranty.
They are a crap seller and if they don't make it right I would start the process of reporting them.
Did they say anything about the shaft being shorter? Although you didn't say how much shorter, at this point I don't have confidence they even sold you the correct shaft.

 

Finally the problem is solved! The driveshaft runs smooth!

 

so... going to share what fixed it?

 

What's up?

 

I just rotated the shaft at the rear flange to make the markings on the shaft and the flange match. That's all I did and it solved the problem.

 

Here we go again. The driveshaft has the drone again from time to time, at least I think it is the shaft. Most of the time it is quiet with just a miner noise and than there is that drone again. Could it be something totally different or just a combination of other causes?

Any idea?

 

Could t be gears?