Trans Fluid Fill Procedure Question (Not the Usual Ones)

[crystalworks]

This is slightly non-X5, but the info will pertain to our E53's as well. Not that anyone would probably be in this situation as there is plenty of room to work on the X5's. Okay, so I am working on an E61 xdrive 530 at the moment. The packaging on it is TIGHT. Like REALLY tight. So I had to drop the exhaust to do the guibo, change the Xfer case fluid, CSB on the driveshaft, and trans/xfer case mount bushing. Question: can I run the engine with the driveshafts disconnected and row through the gears to do the fluid change? DSC switched off obviously. Will the computer freak out? And/or is this bad for the trans or Xfer case? Caveat, this is a pre-lci 5er so it still has the mechanical shifter. If it had the electric one I don't think this would work due to the computer not sensing any wheel speeds and send it into neutral automatically?

Why ask this you wonder? Because of the aforementioned packaging the fluid fill will be infinitely easier with the other stuff out of the way. The fill plug is on the back of the trans FACING the xfer case! WHY?! Why you do this BMW? With the Xfer case bushing out and the trans supported on a stand I have a straight shot to the fill plug.

Thank you to the collective for any infos.

[Clavurion]

There should be no problem going thru gears with driveshafts disconnected.

Isn't the oil fill plug there on the side?

[crystalworks]

There is indeed a plug at that location. But the TIS points to a different 8mm hex fill plug at the back of the trans for fluid fills. Here is the TIS link: TIS trans fluid fill

Now that said. From what I can find EVERYONE, and I mean everyone, uses that fill plug you pointed out. I guess I'll go ahead and do that as well since it is A LOT easier to get to. Plus, then I can rehang the exhaust and I don't have to find out what an open header N52 sounds like.

[bcredliner]

I suspect you will get a code if you run through the gears with driveshaft disconnected. If you want to hear open exhaust I would do so in Park. Then put if back together and use the fill hole as posted. Do you know the trans filling procedure?

[crystalworks]

Originally Posted by bcredliner

I suspect you will get a code if you run through the gears with driveshaft disconnected. If you want to hear open exhaust I would do so in Park. Then put if back together and use the fill hole as posted. Do you know the trans filling procedure?

Thanks BC. I was expecting a code as well, which is fine. Will clear it with the Foxwell after procedure is complete. I've also resolved to using that fill hole everyone posted rather than the one in TIS. Have not found a single instance of someone using the rear fill hole.

I am familiar with the fill procedure, yes. I have about 3.5 liters in it currently and wanted to ask the question before proceeding. In my head everything should be fine running the engine and trans without front/rear driveshafts connected but wanted to confirm.

Maybe I will start the car up without the exhaust just to see what the open headers sound like.

[andrewwynn]

You can run the xdrive with the FRONT driveshaft off but likely NOT the back. You will have no way to stop the spinning of the output shaft. I suppose you can maybe go into neutral. I had a similar problem when I changed the transfer case and wanted to do some testing part way through assembly.

TC doesn't need the precision of transmission I actually filled that before installing into the car.

I remember at one point realizing it would be a problem trying to go from R to P if I can't hit the brakes.

You could possibly go to N and very quickly to P or just turn off the engine when done working through the gears.

[Clavurion]

Originally Posted by andrewwynn

You can run the xdrive with the FRONT driveshaft off but likely NOT the back. You will have no way to stop the spinning of the output shaft. I suppose you can maybe go into neutral. I had a similar problem when I changed the transfer case and wanted to do some testing part way through assembly.

TC doesn't need the precision of transmission I actually filled that before installing into the car.

I remember at one point realizing it would be a problem trying to go from R to P if I can't hit the brakes.

You could possibly go to N and very quickly to P or just turn off the engine when done working through the gears.

Do you worry about the situation going from D to R or from D/R to P position? When torque converter is not locked there's not that much inertia that it should be an actual problem.

[andrewwynn]

Originally Posted by Clavurion

Do you worry about the situation going from D to R or from D/R to P position? When torque converter is not locked there's not that much inertia that it should be an actual problem.

I made the mistake of testing a wheel for scraping parts when I didn't have working brakes once. It was a very unpleasant clank into P. If I had to do again I would shift to N first it should stop within a few seconds and then quicky go from N to P.

I may try that with brakes and wheels on next time I have one of the AWD cars all wheels airborne.

I shift cars all the time from D to R or opposite when moving slowly. I'm not sure how fast the wheels will spin.

Actually: I think for the gears to really mesh you need the output shaft to be moving, prob good for the drive shaft to be off as long as you can use N to stop it. Would love to see some feedback from an expert.

[crystalworks]

I hadn't thought of stopping the drivetrain. Duh. Thanks Andrew. Not sure how long it would take for it to stop by shutting the engine down. But I'd much rather hit the brakes. Fluid fill in xfer case has been completed and bushing replaced (you'd be proud of the "tool" I created to do the job) so I'll replace the flex disk, install heat shields, and the exhaust before continuing the fluid fill. Thanks again.

[wpoll]

This might be the only time I'm glad my ZF trans is bottom fill...