Grand Prix 500
Main Motorcycle: T120 (preunit)
Join Date: Nov 2016
Other Motorcycle: T20C
Hi Kadutz, starting from the inception of the alternator cover fitted to the single down-tube frame, The listed pre 60' T1231 inner cover appears to have the wrong part No. ?; T1231 being ascribed to the 6T rather than the T100 T110 TR6 & T120 alternator models, while T1186 is shown as 6T, so these appear to be listed back to front? (1958, Eng No. 020076, Pg 77; Cat 15). Outer covers appeared with different numbers simply by virtue of varying models insignia cast in. These are the early inner covers I refer to earlier that can only fit correctly with modification. I know you are thorougher with your numbers, maybe you can confirm these number anomalies?
I can't see that parts book 16 is incorrect here. T1603 & T1600 inner case, in the (60-62 Cat 16, Pg 40). were specifically for the duplex frame, and it's additional projecting fittings (outlined earlier), with the recesses (outlined previously). other than this, both 'appear' identical and are interchangeable, excepting that the T1600 for the T120 & TR6 were marginally deeper, (to accommodate a thicker stator?). Again, the outer case numbers only reflected the insignia cast in (Thunderbird). hope this helps.
Apologies, I see where the confusion arose, The 1960-62 chaincase inner were different, while accepting (meaning it will fit) the earlier short alternator outer cover, The 60-62 inner case had two unique recesses, one for the gear box pivot bolt head, just forward of the rear frame bolt, and one recess for the engine mount centre bottom bolt (nut).
Last edited by Freakmaster; 06-12-2019 at 12:51 PM.