Workshop -Transmission

Details for this section are for the Lambretta 175 Li Series 1 and 2 however there are many similarities between these models and other models of Lambretta threewheelers/Lambros. This information and the pictures included are provided from the 'Instructions for Repair Shops' for these models published in 1963. It is intended for informational purposes and we would recommend seeking professional advice before undertaking anything described in the Workshop section.

Transmission

The transmission shaft, of tubular section (Fig. 27) is connected to the engine at the front and rear axle, at the rear by means of two elastic couplings/Rotaflex, which not only act as shock dampers, but ensure the regular transmission of movement during the oscillations of the rear axle respectively to the frame.

 

Each coupling consists of two 3 arm yokes, between which a rubber element is fitted. This element is fitted in a precompression state and to facilitate its substitution the spare part is strapped with a metal band, which must only be removed after assembly to the shaft. Should it be necessary to remove the transmission shaft without the need to replace the couplings, leave these assembled to their yokes. This will render the refitting of the shaft easier. Should a coupling for any reason be detached, this can be refitted with the help of Tool 52832. The front coupling (engine end) has its splined sleeve yoke fixed to the gear box shaft by means of a castle nut, while the other yoke arm, rear axle end, is collated to the transmission shaft by its splined sleeve. This facilitates any axial movement of the transmission shaft caused by the rear axle oscillations.

This splined sleeve must be kept constantly lubricated through the appropriate greaser. Furthermore, check that the rubber protection hose is well clipped on at both ends to avoid entry of dust or water.

To dismantle the transmission shaft, carry out the following instructions.

71	Release the clip fixing the hose on the front engine end of the shaft.
72	Remove the three nuts blocking the elastic element to the rear yoke arm on the rear axle pinion. (Two 14 mm spanners, one for the screws and one for the nuts).
73	Remove the bolts, taking care to contain by hand pressure the elongation of the element so as not to ruin the bolt threads.

74	Withdraw the yoke arm complete with its rubber coupling of the rear end from its special guide by pushing it towards the front of the vehicle. (Take care not to lose the oil seal in the guide). Fig. 28.
75	Lift the shaft sufficiently to allow it to slide from its splined shaft, holding the end of the hose of the front coupling, to avoid its stretching.

 

To reassemble the transmission shaft, execute the above operations in the reverse way and use tool for the precompression of the rubber element, necessary for aligning the element fixing holes with those of the rear yoke arm. To tighten the coupling bolts always use two spanners.

Ensure that the spherical guide is well packed with grease.