1970 650 Gearbox Question

Discussion in 'Vintage Classics' started by Dave UK, Jul 20, 2020.

  1. Dave UK

    Dave UK New Member

    Jan 7, 2020
    23
    3
    Surrey UK
    I’m rebuilding a TR6P (ex police model) from 1970 (engine/frame numbers give July 1970 as build date)
    I thought that 1970 T120/TR6’s had a leaf spring arrangement rather than the earlier sprung plunger on the cam plate..... but on stripping my gearbox, my engine has the plunger arrangement, not the leaf spring.
    It looks to be “factory” to me (but what do I know?)

    So, my question is; did all 1970 bikes come with the leaf spring, or were all police-spec models fitted with the plunger?.... or do you just think that someone has retro-fitted the plunger system.

    Or, have I got my facts wrong, and the leaf spring wasn’t fitted to 1970 bikes at all?

    I know there are people here who know LOTS about the 1960’s triumphs, and wondered if someone with more knowledge than me (ie; most on here) can increase my understanding on the changes that occurred during the lifespan of the pre-OIF models.

    thanks all.

    Dave
     
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  2. darkman

    darkman Crème de la Crème

    Oct 26, 2015
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    All 63-70 pre OIF bikes have the spring it was only later that Triumph simplified the design to save money.
     
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  3. darkman

    darkman Crème de la Crème

    Oct 26, 2015
    7,629
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    Sorry i just reread this reply and it should be spring/plunger for early type just to clarify as both have a spring, the later bikes having the leaf spring.
     
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  4. Dave UK

    Dave UK New Member

    Jan 7, 2020
    23
    3
    Surrey UK

    Thank you. For some reason I had it in my head that they put the leaf spring in from 1970, rather than afterwards. So 1971 bikes and onwards had the leaf spring rather than the spring and plunger?
     
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  5. Peter in Aus

    Peter in Aus New Member

    Sep 14, 2022
    0
    0
    Busselton West Australia
    Hi, I'm having the opposite problem, I'm working on a 68 TR6 gearbox that is jumping out of some gears, all the parts books & manuals I have, show the camplate with index plunger and coil spring, where as this one has the leaf spring.
    I have ordered a new leaf spring what I think is the right one from Draginfly listed as being for a T150/T160 68-75.
    My problem now is how to it get it to mesh with the cameplate and quadrant correctly when assembling, the two manuals I have don't show this with the leaf spring, I don't see how you can do this without moving the came plate when fitting the inner plate.
    Hope some one can give me some advice on how to do this.
    Thanks,
    Peter
     
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