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In addition to my TR6 engine rebuild project, I am also helping a buddy get his 65/68 T120 together. His title says it is a 65, but they frame and all other components clearly indicate it is at least a 68. I found the engine number but can't find the frame number - I looked late last night so I could have missed it but it is not in the place it normally would be. Where 68's different?

Also, how do I find the year for the engine - here is the id - DU16761. Also, the T120 stamp had SR behind it. I looked up the various alphabet combo's that are usually stamped behind the model ID and saw nothing for SR. Any ideas?
 

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Engine number is from a 65 as is the SR designation. Don't know much about bonnevilles, but I don't think there were many SR's made. The frame number should be on the left side of the steering head unless tampered with.
 

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Starting in 67, the fork lock moved to the top of the steering head....there is a flange on the top of the casting with a hole in it. The 66 and earlier frames had the fork lock on the left side of the steering head, about in the center.
It's not uncommon to have rear frames not match the year of the main frame. Starting in 68, the left side panel is retained by two pins on the rear frame downleg and a knob on the upper front, with a tab welded to the rear frame just to the rear of it's top mounting point to the main frame.
65 was the only year which saw the crankshaft located by the LEFT ball main bearing, all others locate the crank by the RIGHT main bearing. When Triumph changed to a roller LEFT main bearing the next year, they went back to the old system, so the internals of the 65 are unique. For me, I would fit the roller to the left and use non-65 spacers, sprocket, and pinion. Just because the factory makes a goof doesn't mean I have to.

[ This message was edited by: Mecchanica on 2007-07-12 11:32 ]
 

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Well Mecchanica, you learn something every day. Today I have learned about the 1965 crankshaft assembly. I had one, rebuilt it and never knew about this 'goof'................. ALWAYS need to learn and I am pleased there are guys out there who are willing to teach us. :)
Roy.
 

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It wasn't so much a goof as a change with no purpose. If both sides use ball bearings, then locating it by one is as good as the other, but I find it hard to believe that they didn't know they were going to change main bearings in 1966 when they decided to change the crank stuff. Just seemed strange.
The leaf spring detent is another one. Changed something which was nearly flawless and could be changed from the outside, to something which didn't work as well and couldn't be changed unless you pulled both the outer and inner covers. Duh.
 

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Unfortunately my friend, that was the BSA influence. I have had many a conversation with John R. Nelson (our club Patron) regarding the 'BSA influence' he is still very bitter about that time. That was really the begining of the end, SLUMBERGLADE......................................
Roy.
 

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Bsa

Agreed. I remember Jack Wilson raging at the Factory when they tried to get the Triumph dealers to also sell and service BSAs. He threatened to dump them and sell Hondas and, I think Bridgestones. So did a lot of other dealers. The factory relented.
 
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