Driveshaft came apart while pulling the diff

[mach schnell]

I was in the process of removing the diff from my ‘89 325i... as I pulled back on the diff, I didn’t realize the driveshaft was still attached (even though the 4 bolts were removed), so the rear half of the driveshaft came out of the car with the diff. It came out very easily, with little to no resistance.

Do I just push it back down into the front half?

Or do I have to align it in a particular manner?

Don’t want to have driveshaft vibrations from putting it back together wrong.

[e30austin]

The front and rear u joints need to be in plane with each other, so yes, you will need to properly orientate it.

The factory (usually) marks the two halves, with a white dot, on each side, respectively.

[mach schnell]

Argh. Ok. Thanks. Do I have to pull all of the exhaust and heat shielding to be able to see those marks....???

[e30austin]

Unless you have x-ray vision, yes.

You will need to take the driveshaft out of the car.

[mach schnell]

Unless you have x-ray vision, yes.

You will need to take the driveshaft out of the car.

Dang it.

I was really hoping to avoid that. What a pain in the ass.

Thanks for the info!

[mach schnell]

If there are no white marks, how else can I align it properly?

[roguetoaster]

If there are no white marks, how else can I align it properly?

Look for any scratches or other type of indicator of alignment. Otherwise you're screwed.

[mach schnell]

Look for any scratches or other type of indicator of alignment. Otherwise you're screwed.

Have to take it to a driveshaft shop at that point?

[AndrewBird]

Like Austin said, the u-joints just need to align with each other. They can only align 2 different ways. More than likely it won't vibrate in both position.

[mach schnell]

I got it back together. I found the white marks, and I think it’s together correctly. No vibration so far....

Thanks for all the help.