question about flex disc (guibos)

[iXguido]

Why is there a guibo between the transmission and the transfer case, when there is one between the TC and the rear driveshaft and between the front DS and front differential?

Isn't the one between the transmission and TC somewhat redundant?

Please explain

[AndrewBird]

The point of the guibo is to allow a tiny bit of misalignment in the connection, hence why you need one at every connection. Otherwise the tiny bit of misalignment you have would create vibration.

[Nisse Järnet]

Shock damper?

[The Dark Side of Will]

I think BMW's engineering standards use guibos more for taking the edge off transient loads (e.g. clutch drops) than for misalignment, although they are used for misalignment and other reasons as well.

The automatic IX's do NOT have a guibo between the trans and T-case, and the automatic RWD BMW's use a U-joint at the back of the transmission instead of a guibo. I think this is because the torque converter does not transmit high transient loads.

The iX's use a guibo at the back of the T-case to minimize the parts differences between auto and stick cars, I think.

I think the front driveshaft guibo in an iX is for potential misalignment, but it also enables removal of the fixed length driveshaft, thereby supporting a simpler, cheaper driveshaft.

[z122643]

What he said...

I think BMW's engineering standards use guibos more for taking the edge off transient loads (e.g. clutch drops) than for misalignment, although they are used for misalignment and other reasons as well.

The automatic IX's do NOT have a guibo between the trans and T-case, and the RWD BMW's use a U-joint at the back of the transmission instead of a guibo. I think this is because the torque converter does not transmit high transient loads.

The iX's use a guibo at the back of the T-case to minimize the parts differences between auto and stick cars, I think.

I think the front driveshaft guibo in an iX is for potential misalignment, but it also enables removal of the fixed length driveshaft, thereby supporting a simpler, cheaper driveshaft.

[iXguido]

Thanks everyone, I understand much better now! Cheers!