Author Topic: 2-3 shift knock  (Read 3836 times)

0 Members and 1 Guest are viewing this topic.

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
2-3 shift knock
« on: July 17 2022, 07:20:51 PM »
Messing with kids car again. Seems like at the 2-3 shift the car is sensing knock. 1-2 & 3-4 are smooth but 2-3 is harsh. I dropped tranny pan to confirm tv cable is adjusted correctly. Any ideas what else this might be??
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline nocooler

  • Administrator
  • Turbo Street Eliminator
  • ******
  • Posts: 1786
  • PSI: 3
    • View Profile
Re: 2-3 shift knock
« Reply #1 on: July 17 2022, 07:22:45 PM »
Is the converter locked in 2nd gear before the shift?
IhaveaV8

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #2 on: July 17 2022, 07:48:52 PM »
Nope
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #3 on: July 17 2022, 09:17:40 PM »
Could it be the rear end. If I remove the driveshaft how much "play" should be there? Like if it is engaging the gear at a marked 12 o'clock forward, how far backwards should I turn it before it engages backwards...if that makes sence
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Scoobum

  • Turbo Street Outlaw
  • *******
  • Posts: 5549
  • PSI: 3
  • YOU CAN'T HANDLE THE TRUTH!!!!
    • View Profile
Re: 2-3 shift knock
« Reply #4 on: July 17 2022, 10:02:03 PM »
Post the PL file.
Hard work pays off, dreams come true. Bad times don't last, but BAD GUYS do!

RIP Scott Hall AKA Razor Ramon

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #5 on: July 18 2022, 12:03:33 AM »
Don't have a logger for this car
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: 2-3 shift knock
« Reply #6 on: July 18 2022, 10:02:51 PM »
If the 2-3 shift is hard, I am guessing that the ecm is pulling timing because it heard that thump, or maybe felt that thump is a better term.  Other than being sure the engine mounts and tranny mounts are in good condition followed by making sure the idler pulley is not hitting the AC clutch and the exhaust is not hitting somewhere along the line from the upper A arm back thru the rest of the run, I guess live with it.  If it's not slipping, I don't think I would spend any money on the the transmission at this time.
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline 1 RARE T

  • Bone Stock
  • **
  • Posts: 95
  • PSI: 2
  • Boost n00b
    • View Profile
Re: 2-3 shift knock
« Reply #7 on: July 19 2022, 09:58:17 AM »
You could be on the raged edge of lean and the load from going into 3rd gear is too much.

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #8 on: July 19 2022, 11:23:33 AM »
Thanks guys!
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #9 on: July 21 2022, 03:06:00 PM »
Mark put new motor and trans mounts in car but they are cheap so replacing them. We just put a Pypes dual exhaust on the cars and no clearence or hitting issues there.
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: 2-3 shift knock
« Reply #10 on: July 21 2022, 05:01:07 PM »
Video the scanmaster as it shifts into third.  If it shows timing retard and then immediately goes away, it is most likely just hearing/feeling the shift.  If it hangs on and diminishes more slowly, it might be lean on the shift. 

Watch the timing retard and O2s on the video.
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline Scoobum

  • Turbo Street Outlaw
  • *******
  • Posts: 5549
  • PSI: 3
  • YOU CAN'T HANDLE THE TRUTH!!!!
    • View Profile
Re: 2-3 shift knock
« Reply #11 on: July 21 2022, 06:07:26 PM »
Don't have a logger for this car

PL is cheaper than changing headgaskets. Guessing is never a good idea.
Hard work pays off, dreams come true. Bad times don't last, but BAD GUYS do!

RIP Scott Hall AKA Razor Ramon

Offline Shimy87

  • Turbo Street Eliminator
  • ******
  • Posts: 1238
  • PSI: 2
    • View Profile
Re: 2-3 shift knock
« Reply #12 on: July 21 2022, 11:44:36 PM »
The video is a great idea

I know a PL would be good but I like to live dangerously :icon_lol:
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Scoobum

  • Turbo Street Outlaw
  • *******
  • Posts: 5549
  • PSI: 3
  • YOU CAN'T HANDLE THE TRUTH!!!!
    • View Profile
Re: 2-3 shift knock
« Reply #13 on: July 22 2022, 12:17:58 AM »
The video is a great idea

I know a PL would be good but I like to live dangerously :icon_lol:

I have vids on how to change head gaskets.
Hard work pays off, dreams come true. Bad times don't last, but BAD GUYS do!

RIP Scott Hall AKA Razor Ramon

Offline Steve Wood

  • Turbo Street Outlaw
  • *******
  • Posts: 9882
  • PSI: 34
    • View Profile
    • http://www.vortexbuicks-etc.com/
Re: 2-3 shift knock
« Reply #14 on: July 22 2022, 09:17:14 AM »
The video is a great idea

I know a PL would be good but I like to live dangerously :icon_lol:

Assuming you are running your usual near stock boost levels, this should work fine.  You might say "Now" when it shifts so you can go back and better pinpoint the shift point as it will be about one frame before you hear "now" (or maybe  less since you are younger and don't have thought to mouth lag like me.
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

 

SimplePortal 2.3.7 © 2008-2024, SimplePortal