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  1. #1
    Veteran Member Three Rings MarkChai's Avatar
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    1998 Titus Quasi-Moto
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    Lets' talk about what happens when someone doesn't put a pilot bearing back in...

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    ...After a tranny/clutch repair/replacement.

    Still investigating the circumstances, but a repair conducted before I bought the car resulted in the above omission.

    input shaft is f'ed up big time and will need to be replaced. Car hasn't been torn down yet, so I don't know what else was damaged. Car went up to 14,000 miles under this condition.

    All I know is last week I left the house, went from 1st to 2nd to neutral and back to 2nd, and when i got back to 2nd, the car wouldn't go any further. There was a scraping/squealing noise when I let the clutch out, but it wouldn't generate any friction to make the car go. I thought it seemed unusual for such a catastrophic failure, so I sent the car in for warranty repair.

    That was probably just my clutch going out, but the missing pilot bearing was discovered upon clutch removal. Could the missing pilot bearing have made the clutch wear out faster?

    I'll find out eventually, but what other damaged parts/components may be in store?

    Also, in pic #2 there is some other shaft sticking out of the tranny that looks chewed up as well, even maybe overheated, which the tech pointed out to me. What is that?

    some pics:




    input shaft:


    input shaft again:


    wide angle:
    Last edited by MarkChai; 01-02-2008 at 03:54 PM.

  2. #2
    Veteran Member Four Rings old guy's Avatar
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    '13 A5, '24 Tiguan SEL R-Line
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    Absolutely running without a pilot bushing will destroy your clutch as well as your input shaft. Quite honestly I find it hard to believe that it lasted 14K miles that way. It must have vibrated the whole time. By not having a pilot shaft bushing the pilot shaft doesn't stay on center which allows the clutch to clamp off center. I guessing you will find more worn parts in the tranny when you replace the pilot shaft. Probably the input gears to the lay shaft as well as the front case bearings are heavily worn. And the rod in your pic is the transmission shift rod that engages the shifter stirrups internally to allow you to shift gears.
    '03 A4 5-MT Motoza tuned Frankenturbo F21L With full supporting mods. Sold (and missed dearly).
    '13 A5 6-MT Needs more Fun Stuff: Neuspeed PM / 3.0 TDI Intercooler / H&R OE Sport Springs / Bilstein B8 Shocks / TyrolSport Brake Stiffeners / ECS Short Shifter / S5 Side Skirts / RS Grille

  3. #3
    Veteran Member Four Rings dougyfresh's Avatar
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    2 pedals 1FG
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    connecticut

    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    That is a shame to hear, but a first-hand lesson on what happens when people cut corners in automotive repairs. I hope nothing else in your AVant was repaired in a similar fashion..

    old_guy is on the money once again!

    Seeing the shifter rod protruding much further out of the transmission case as normal leads me to believe many internals are in bad shape.

    I suggest a full trans rebuild or source a new transmission.

    I am guessing this is a 6spd since the shifter rod is on the driver side of the trans? My 5spd is on the passenger side (but I've never seen a 6spd).

    Is there any way you can take a better picture of that input shaft? The second (close-up) is very blurry. Might want to try the macro function on your PointAndShoot (assuming that's the style camera you are using).
    Last edited by dougyfresh; 01-02-2008 at 05:11 PM. Reason: spelling
    -Doug
    2002 A4 Avant EPL tuned 2.7T K04 6spd

  4. #4
    Veteran Member Three Rings MarkChai's Avatar
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    1998 Titus Quasi-Moto
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    Quote Originally Posted by dougyfresh View Post
    .

    I am guessing this is a 6spd since the shifter rod is on the driver side of the trans? My 5spd is on the passenger side (but I've never seen a 6spd).

    Is there any way you can take a better picture of that input shaft? The second (close-up) is very blurry. Might want to try the macro function on your PointAndShoot (assuming that's the style camera you are using).
    Thanks for the info, gentlemen! One more question: what was the input shaft grinding against (which i presume is whatever else is usually in contact with the pilot bearing?)

    "replace transmission" did come out of the manager's mouth, so I kind of figured.

    Old guy, the car/tranny/clutch did seem to vibrate to me when I was starting off from a standstill, the entire time I've had the car. Multiple techs from different shops drove it and said they couldn't feel any problems. I also had a weird problem this summer with the clutch pedal losing stiffness and getting stuck halfway, and then changing engagement points, but it only happened for a week.

    dougyfresh, Yes, it is a 6-spd... Those pics were taken by the shop... I'll document everything myself at some point and post more images then.
    Formerly:
    B7 A4 Saloon CVT :P
    C4 A6 Avant Quattro
    B6 A4 Avant USP 6QM
    B5 A4 Saloon Q-Tip

  5. #5
    Veteran Member Four Rings old guy's Avatar
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    The input shaft was banging around in the back of the crankshaft and has probably wallowed it out a bit. The pilot bushing centers the input shaft in the back of the crank. Should be repairable. May need an oversized bushing if the crank shows excessive wear.
    '03 A4 5-MT Motoza tuned Frankenturbo F21L With full supporting mods. Sold (and missed dearly).
    '13 A5 6-MT Needs more Fun Stuff: Neuspeed PM / 3.0 TDI Intercooler / H&R OE Sport Springs / Bilstein B8 Shocks / TyrolSport Brake Stiffeners / ECS Short Shifter / S5 Side Skirts / RS Grille

  6. #6
    Veteran Member Three Rings MarkChai's Avatar
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    1998 Titus Quasi-Moto
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    Quote Originally Posted by old guy View Post
    The input shaft was banging around in the back of the crankshaft and has probably wallowed it out a bit. The pilot bushing centers the input shaft in the back of the crank. Should be repairable. May need an oversized bushing if the crank shows excessive wear.

    OK, That sounds familiar. Old Guy, where did the shavings from the input shaft most likely wind up? Should I be worried about that?
    Formerly:
    B7 A4 Saloon CVT :P
    C4 A6 Avant Quattro
    B6 A4 Avant USP 6QM
    B5 A4 Saloon Q-Tip

  7. #7
    Veteran Member Four Rings old guy's Avatar
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    '13 A5, '24 Tiguan SEL R-Line
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    Quote Originally Posted by MarkChai View Post
    OK, That sounds familiar. Old Guy, where did the shavings from the input shaft most likely wind up? Should I be worried about that?
    No worries. They just ended up inside the bell housing with the rest of the clutch dust.
    '03 A4 5-MT Motoza tuned Frankenturbo F21L With full supporting mods. Sold (and missed dearly).
    '13 A5 6-MT Needs more Fun Stuff: Neuspeed PM / 3.0 TDI Intercooler / H&R OE Sport Springs / Bilstein B8 Shocks / TyrolSport Brake Stiffeners / ECS Short Shifter / S5 Side Skirts / RS Grille

  8. #8
    Veteran Member Four Rings absolutegtr's Avatar
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    2001 BMW 540i M-sport
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    Charleston, SC

    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    /\ Good thing I remember to install my pilot bearing......lol

    This is EXACTLY why I do my own work...
    -Sami-

  9. #9
    Veteran Member Four Rings Papachristou's Avatar
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    Re: Lets' talk about what happens when someone doesn't put a pilot bearing back in...

    nothing like having left over parts!
    2018 Audi S6 Prestige Sport Sepang Blue/Lunar Silver
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