Cammed VTS destroying gearboxes

  1. Newbie Joined: Sep 2013 Graz - Austria Posts: 28 Saxo 1.6 VTS (2000) Husqvarna SMS 630 (2012)
    #1
    Last winter i rebuilt my engine, fitted new driveshafts, wishbones, shocks, clutch and so on.

    Since then i had 3 broken Gearboxes in about 4kkm.
    Every time bearing issues from the input shaft or the differential.
    After two broken gearbox each lasted maybe 1kkm (input shaft play) i swapped the crank from my old engine in.
    Then put the crank on some bearings and measured 3/100mm radial "dimensional deviation" when you turn it.

    Now the gearbox lasted nearly 2kkm. then this happened.
    http://www.saxperience.com/forum/showthread.php?t=8547.
    The crown wheel came loose on the differential.
    One cv boot from the short driveshaft was torn, so replaced that one, but there was no damage inside of it and i cannot explain how the boot twisted itself?

    First Gearbox was a VTS Box, second was a 1.4XSI, third was a 1.4 Furio.

    Today i've fitted my 4th gearbox and i noticed that the driveshaft has play in the gearbox. (short one, drivers side for me and passenger side for you, beacause mine is lhd).

    The driveshaft shouldnt't have any play whatsoever? am i right?
    so had 2 other boxes lying around tried the driveshaft in every one of them and everytime the same play when its in?
    I'm not sure about my english here but maybe i bought some "reject goods" as new driveshafts.
    The first two boxes where damaged beacause of the bad crankshaft, but maybe they werent just not long enought in the car to have the same problem as gearbox number 3?

    Can the driveshaft with play be responsible for my 3th broken gearbox?
    The driveshafts where from the brand "cevam" cost me about 130 euros for both.
  2. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #2
    sounds like your 4th gearbox is very worn already, with massive play in the differential unit or bearings.

    throwing used MA boxes into a vehicle used hard with very little mechanical sympathy will inevitably lead to regular failures.

    fit a rebuilt unit and they will last longer, fit a BE4 gearbox and you wont have any problems.
  3. Saxperience Addict Joined: Dec 2009 Posts: 11714 A6 Le Mans tuned/A3 TFSI tuned
    #3
    Don't replace a worn box with another worn box, and this won't happen.
  4. Newbie Joined: Sep 2013 Graz - Austria Posts: 28 Saxo 1.6 VTS (2000) Husqvarna SMS 630 (2012)
    #4
    I allready ordered a new set of bearings for my 1.4xsi box, will rebuild that one with the 5th gear out of the 1.4 furio box.

    I'm going to post again when the new gearbox is in and if it solved the problem...
  5. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #5
    dont forget new planet gears or an lsd.
  6. Newbie Joined: Sep 2013 Graz - Austria Posts: 28 Saxo 1.6 VTS (2000) Husqvarna SMS 630 (2012)
    #6
    Why do i need new planet gears or an lsd?
    Everyone here drives standard boxes on their saxo vts with newman ph3.
    Havent got the time and and money to buy an lsd.
  7. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #7
    because they are a weak point.
  8. Regular Poster Joined: Sep 2015 Posts: 269 106 Rallye
    #8
    Adjusting your driving style would be the cheapest option. If you're mangling gearboxes that often you're not showing them much mechanical sympathy.
    2 users thanked this post: ,
  9. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #9
    quite true, I know there are quite a few 200 bhp + 150lbft+ cars still running MA casings, often with synchro gearsets too.
  10. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #10
    flipside of it is a Group N tarmac Rally car I used to service for broke 5 boxes, with quaife and peugeot sport internals, that was essentially stock blueprinted engine with cupcar cams.

    rally slicks and changing surfaces with an aggressive driving style introduces massive snatch loads which causes things to break very quickly.

    the higher torque engines cause the casings to flex which can break teeth off gears!
  11. Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.
    #11
    flipside of it is a Group N tarmac Rally car I used to service for broke 5 boxes, with quaife and peugeot sport internals, that was essentially stock blueprinted engine with cupcar cams.

    rally slicks and changing surfaces with an aggressive driving style introduces massive snatch loads which causes things to break very quickly.

    the higher torque engines cause the casings to flex which can break teeth off gears!
    1 user thanked this post:
  12. Newbie Joined: Sep 2013 Graz - Austria Posts: 28 Saxo 1.6 VTS (2000) Husqvarna SMS 630 (2012)
    #12
    Ok i hope that it will last at least one or two years.

    And how do i change that? I am not launching it hard, no burnouts, no no-lift shifts.
    i do drive fast on b roads and do rev it out to 7880 rpm...
  13. Newbie Joined: Sep 2013 Graz - Austria Posts: 28 Saxo 1.6 VTS (2000) Husqvarna SMS 630 (2012)
    #13
    So the new Gearbox is in, have been driving a few hundred km since then and no issues.
    I do not have any slicks on there, i'm running conti sport contacts 195/45 R15...

    If it breaks again, i will tell how long it lasted
  14. Regular Poster Joined: Sep 2015 Posts: 269 106 Rallye
    #14
    Are you using the correct weight MTF? As Welshpug said, a change of surfaces whilst driving hard will put stress on the gearbox.

    Are you engauging the clutch fully when you're shifting?

    Apart from that, if you're not being rough on it, I'm not sure what else could be wrong unless you've just had a bad run of already worn gearboxes.