Dear Anirban - regarding your query on the propeller shaft guide, the rear end of the mainshaft of the transmission carries a semi-spherical OD ground guide, the ID of which is supposed to be a light hammer fit on the OD of the shaft. In order to retain it in place, a small circlip is fitted. The front yoke of the propeller shaft has a ground ID which just slides on this semi-sphere. Therefore, concentricity is ensured. The maximum propeller shaft angle with respect to the transmission centre line is 13 degrees. The bolts then transmit torque. The coupling takes 13 degrees as there are wire ropes inside it designed to take this angle. Over a period of time, the sphere has a tendency to become a little loose and therefore there will be relative angular movement between it and the mainshaft. This causes heat buildup which jams the sphere on the shaft. For some silly reason for which I find absolutely no rationality, some mechanics tend to remove the sphere altogether. If so, it is a sure disaster because the propeller shaft's whipping at high speed will spoil something and the weakest link is the rubber coupling (whirling speed factor of safety is 1.15). Also the quality of the coupling itself seems to be suspect. Anyways, I am changing the transmission of BLB1144 shortly alongwith a new clutch so will see. You also get your car checked for this when you are back. Don't let somebody open it, it may get spoilt further. I have the shop manual. I will tell Cyrus to scan the cross section and send you.
Best regards,
Behram Dhabhar |