Wednesday 16 March 2016

Triumph T300 starter-clutch fix (without repair-kit)

Quite recently a mate contacted me and told me that the starter-clutch was slipping on his Triumph T400 Tiger 900 (carb-model).

Now being quite experienced with starter malarkey of all sorts from both my Yamaha TR1, but also from my Kawa Zed days, I quite simply assumed that it would be a slightly tedious, yet cheap and inexpensive fix. I was wrong. There was a repair-kit, which was substantially cheaper (around 160 Euros) than the complete starter clutch assembly (250 to 280 Euros depending on the dealer), yet I didn't quite consider this satisfactory.

 This is the starter clutch in question. On T300-series Triumphs this little Renolds sprag clutch tends to give in as early as at fifty to sixty-thousand kilometers. As the actual teeth are of so-called logarithmic shape they hardly ever wear out, normally it is the spring, which provides the initial tension, that breaks and thus renders the starter clutch useless.

 Now the correct spring is quite easy to get as it hides in a 45x55x7mm fork seal and can be carefully extracted.
This is the little circular spring, it is a tad shorter and a bit stronger than the stock spring, yet maintains the same diameter.
 The sprag clutch has got a groove machined into it, in which the spring has to be slid in.
 Aside from the actual clutch bearing the starter clutch consists of the parts above.
 This picture is merely meant to help you with the question of which way round should it go in...
Cleaned and re-assembled starter clutch. Depending on whether you have an early T300 (with a cover) or a later model T300 (without a cover) this can now be a relatively quick job or a horrid and painful adventure, which includes splitting the cases and pretty much hacking the whole lower end of the engine apart. (It's doable in about a day - both assembly and disassembly.)


6 comments:

  1. Gudday from Wodonga Australia. I have an T400 with cover and need to replace sprag spring. I know it's a while since u did this job. But can u change it thru the cover and NOT split cases?

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  2. G’day to Wodonga!

    Sorry for the late response, but I was wanting to take my time and respond with a proper answer and not just the usual: “It depends, mate…”

    So as a matter of fact it actually depends on the modelyear of your Tiger. Early(-ier) models used to have a little cover right next to the starter and if so, you can actually do it. My mate Dominik’s bike didn’t, so guess what.

    I doubt that it’ll be a funny job, but a hell of a lot quicker than it was for us.

    Hope this helps
    Greg

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  3. Thanks for giving it some thought. I can confirm it will give access. I am waiting on parts. About 3 to 5 weeks from UK! I didn't pull it apart but it was pretty messed up inside. Aust$700 to get parts.

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  4. Hi,can you help me with some info please? I'm into this same job on mu 1995 Tiger.I've got 51 teeth on the clutch gear,10 on the starter gear.My supplier lists sprag clutches for the 1995 Tiger as 51-15 and 53-13 but not for 51-10.Somebody must be wrong here!
    How many teeth on your starter gear? (end of the starter unit)

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  5. Excellent overview, thank you very much! (-Cody: Recently resurrected 2003 Triumph Sprint ST ---> [Sprag = "clickety clack"])

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    Replies
    1. Glad to hear it. Seems like this was one of my most successful bodges of all time on this blog.

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