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Thread: Geartrain noise in 4L60E second gear causing "knock" retard

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  1. #1
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    Geartrain noise in 4L60E second gear causing "knock" retard

    I am about to pull my hair out with this one. Have any of you seen a transmission cause false knock only in 2nd gear??? I can hear a whine in the transmission at about 4,000+ in second gear. At 4,400 I start seeing knock retard that quickly peaks 8°. I can slightly reduce the "knock by retarding the timing to rediculous values but not eliminate it. I made a run from a standing start to better than 90 mph and practically no knock in 1st or 3rd gear but massive amounts in 2nd that vanishes quickly after a WOT 2-3 shift, despite the engine being under more load, with more timing and less rpm.

    Prior to the 0411 swap I ran a LT4 knock module and rarely ever saw knock retard even with 26-28° total advance.

    Edit---This was meant for the OBD2 board...Darn phone.
    Last edited by Fast355; 04-13-2013 at 05:12 AM.

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    maybe talk to Dana at Probilt and find out what could cause the racket in 2nd gear?
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    Moved your thread for you. Wish I had an anwer but never dealt with this before.

    Can you actually here some noise in second gear?

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    Quote Originally Posted by EagleMark View Post
    Moved your thread for you. Wish I had an anwer but never dealt with this before.

    Can you actually here some noise in second gear?
    I appreciate you relocating this for me. Posting from my phone gets me sometimes.

    Yes I can, sounds almost like a quiet gear drive the way it whines.

    I messed around with it today and it responded very well to a Ramjet timing map. 30-31* total advance, 11.8:1 PE air/fuel ratio and 93 octane gasoline turned it into a rocket compared to how it was running. On another note....I am out of fuel at WOT now. Guess that TPI is going on sooner than later

    The weirdest part of it all is sometimes it will retard the timing and other times it won't. I am seeing the same amount of retard at 18* timing as I am at 30-31*. I attached a few screen shots of 1st and 2nd gear runs and a WOT 1-2 shift.
    Attached Images Attached Images
    Last edited by Fast355; 04-13-2013 at 11:46 PM.

  5. #5
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    This is the stock spark map creating 8* of retard in 2nd gear! With this much knock on the stock tune, I do not feel this knock is actually knock, it has to be false knock.
    Attached Images Attached Images
    Last edited by Fast355; 04-14-2013 at 12:08 AM.

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    The weirdest part of it all is sometimes it will retard the timing and other times it won't.
    Sure it's not Cat protection?

    That log picture 3 looks like it may be trans torque reduction for shift?

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    Quote Originally Posted by Fast355 View Post
    I messed around with it today and it responded very well to a Ramjet timing map. 30-31* total advance, 11.8:1 PE air/fuel ratio and 93 octane gasoline turned it into a rocket compared to how it was running. On another note....I am out of fuel at WOT now. Guess that TPI is going on sooner than later
    Have a copy of that Ram Jet spark table I could eyeball? I googled around and found nothing.
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    Quote Originally Posted by brian617 View Post
    Have a copy of that Ram Jet spark table I could eyeball? I googled around and found nothing.
    It is on Thirdgen.org, the copy I made from that info was converted to work with the LS style timing map. I also have a Hypertech spark map for a L31 with 5 speed. They only really made WOT changes due to emissions compliance though.

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