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  1. #1
    Member Mrkszoo's Avatar
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    Default Lotus 51 Half Shaft Help

    Greetings all,

    In the process of trying to install the half shafts onto my Lotus Mk. 51. And I am running into some difficulties and questions.

    First, Is there a proper procedure for installing those shafts?!? I can mate the outboard yoke (attached to the u-joint) with the splines on the stub axle. I can even slip the washer and nut into the space between the yoke and the u-joint. More amazingly, I can start the nut and tighten it somewhat by finger. How do I tighten the nut fully?!? (The entire halfshaft is assembled. The u-joint has been pressed into the both the yoke and the half shaft.) Is there a special tool required to tighten that nut?!? (It almost seems like the yoke must be assembled onto the stub axle, the nut tightened, and then the u-joint pressed into the yoke.)

    Second, Is there a "standard" length for the halfshafts on a Lotus 51 with a Hewland gearbox?!? If so what is it and how is it measured?!? In the assembly process, I have had to turn the upper and lower Heim joints out of their respective suspension members until there is but one-quarter inch of thread left engaging the threads on the suspension arms. This doesn't seem right. To say nothing of removing alot of the suspension's adjustment. It seems like the halfshafts are too long... They measure 15 and 1/2 inches in total length (from the outside edge of the stub axle yoke to the outside edge of the yoke that bolts to the drive doughnut).

    As always, any and all assistance is greatly appreciate.

    Have a good weekend.

    Sincerely,

    Mark Patterson
    Hesperia, Ca
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

  2. #2
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    Default

    "It almost seems like the yoke must be assembled onto the stub axle, the nut tightened, and then the u-joint pressed into the yoke"

    Yep, that's the way it works on my Brabham, except that it's a bolt head that needs to be tightened. Sometimes you can make a thinned-down open wrench work, for some cars.

  3. #3
    Member Mrkszoo's Avatar
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    Default

    Quote Originally Posted by timos View Post
    "It almost seems like the yoke must be assembled onto the stub axle, the nut tightened, and then the u-joint pressed into the yoke"

    Yep, that's the way it works on my Brabham, except that it's a bolt head that needs to be tightened. Sometimes you can make a thinned-down open wrench work, for some cars.
    That thought occurred... Which might explain the acrid smoke smell...

    Thanks for the suggestion.
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

  4. #4
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    Default Halfshaft Length

    Quote Originally Posted by Mrkszoo View Post

    They measure 15 and 1/2 inches in total length (from the outside edge of the stub axle yoke to the outside edge of the yoke that bolts to the drive doughnut).

    From the face mating to the donut to the centre of the universal joint yoke on the shaft is less than 12 inches on my 61.

    Hope this helps...

    Rob

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    Member Mrkszoo's Avatar
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    Quote Originally Posted by Rob McClelland View Post
    From the face mating to the donut to the centre of the universal joint yoke on the shaft is less than 12 inches on my 61.

    Hope this helps...

    Rob
    Rob,

    Thanks for the input.

    I measured the same dimension on my halfshafts... Almost 13 1/2 inches. :-/ I'm beginning to think they will need to be shortened an inch.

    Mark
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

  6. #6
    Member Skeeters's Avatar
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    According to Bob West, the Mk 51 had two different transmissions. Renault and Hewland. Perhaps you have a Renault halfshaft?

    You should give him a call;
    Bob West
    805.276.0046
    Tehachapi, Ca

  7. #7
    Member Mrkszoo's Avatar
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    Quote Originally Posted by Skeeters View Post
    According to Bob West, the Mk 51 had two different transmissions. Renault and Hewland. Perhaps you have a Renault halfshaft?

    You should give him a call;
    Bob West
    805.276.0046
    Tehachapi, Ca
    Thank you for the suggestion. I will call him.

    Mark
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

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    Member Mrkszoo's Avatar
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    Update:

    Had the half shafts shortened one inch at the beginning of the week. Spent the afternoon bolting them up along with donut savers.

    The half shafts fit up beautifully.

    However... How do I tighten the lock nut sandwiched between the u-joint and the yoke?!?

    Is there a special tool available that I need to purchase for the task?!?

    Any and all suggestions are greatly appreciated.

    Sincerely,

    Mark Patterson
    Hesperia, Ca
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

  9. #9
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    Default Attaching the Yoke

    Quote Originally Posted by Mrkszoo View Post

    However... How do I tighten the lock nut sandwiched between the u-joint and the yoke?!?

    Is there a special tool available that I need to purchase for the task?!?

    Mark,

    No special tool is needed, it rests simply with the order of completion. Bolt up the yoke to the outboard drive shaft in the carrier housing first. Then attach the universal joint to the yoke followed by the connection with the halfshaft. You work from the outside towards the centre line of the car.

    Rob

  10. #10
    Member Mrkszoo's Avatar
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    Rob,

    Thank you for the response. It is very informative.

    Herein lies the problem... The u-joints were already installed in the half shafts... :-/

    Mark
    1968 Lotus Mk. 51 Formula Ford
    VARA and SVRA West Number 35

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