Transmission - 4 speed clutch input hub

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models

Created: 2016 October 14

Updated: 2016 October 14

Thanks to Dominic Etzold of Symphony Cycles for sending me this information via email. In Dominic's own words:

[Below] are the pictures of both the earlier V700 clutch input hub/input shaft and the later Ambassador one. Guzziology mentions that the early stuff went up to engine #2119. It also lists the part number for both the input shaft circlips and the clutch hubs as being identical for all 4-speeds, however the 1967 parts book actually gives the part number for the clutch hub as MG# 12081800 (instead of MG# 12081801 that Guzziology lists for all 4-speeds) and the part number for the circlips as MG# 90271023 (instead of MG# 90271025). Concerning the circlips the 23 in the early 700 part number corresponds to the diameter of the clip (23 mm) just as the later 25 corresponds to 25 mm. As mentioned before, the early V700 only calls for one circlip to be used, even though the input shaft is machined to accept two.

Here's the measurements:

• Early V700 input shaft spline diameter - 23 mm, clutch hub slides right on, not an interference fit.
• Later input shaft spline diameter - approximately 25 mm. Clutch hub is an interference fit.
• Distance between circlips - approximately 18 mm for both the early and later versions.

As can be seen in the pictures, the later clutch hub will probably work on the early input shaft, albeit with a 2 mm gap above the input shaft splines to the hub, but there is no way for an early hub to be used on the later input shaft.

The later model circlips are too wide to be used on the early ones. Should be obvious given the different part numbers and diameters.