Hard shift into 2nd sometimes
Hard shift into 2nd sometimes Any ideas why my car will shift hard into second sometimes? Trans is A4.
Everything is stock as far as i know but i can be driving it and it will really hit into 2nd just driving normally or sometimes it will be so smooth you hardly notice but most of the time it shifts pretty hard into 2nd.
The car has had mods done to it by previous owner so if he did do something to the trans is their anyway I can tell or find out what it was?
Everything is stock as far as i know but i can be driving it and it will really hit into 2nd just driving normally or sometimes it will be so smooth you hardly notice but most of the time it shifts pretty hard into 2nd.
The car has had mods done to it by previous owner so if he did do something to the trans is their anyway I can tell or find out what it was?
Well a firm shift into second is not atall a bad thing , I would really only be worried about why its real smoothe sometimes and why it intermitant either way , but things that come to mind are.
1-CHECKBALL GETTING STUCK IN THE PLATE
2- SOME ACCUMULATOR ISSUE
3- FAILING OR STICKING PCS IF A 4L60E
1-CHECKBALL GETTING STUCK IN THE PLATE
2- SOME ACCUMULATOR ISSUE
3- FAILING OR STICKING PCS IF A 4L60E
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well car is a 98 z28 so i have no idea what specific trans it is. Also about the only time it shifts smooth is if i let off the gas right before it shifts or i am beating the heck out of it but most the time its a pretty firm shift.
Well thats sounds normal for a stock trans , I have noted that even with a stock trans there are ceetain conditions where you can get and ovely agressive shift, Though there is nothing wrong. I would not worry to much , Have you had this car long?
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I'm fighting a similar problem in my 00 WS6. I have HPTuner, but am pretty new to it so I don't really know much about what I'm doing. I HAVE noticed that as tranny temp goes up, the shift gets smoother.
In my case, I've messed around with several things, but not getting the effect I'm looking for. Here's what I've done:
TO KEEP IT OUT OF PANZY MODE:
Transmission - Disable Abuse Mode
Transmission - Set RPM, TPS, Speed =0
Transmission-Torque Reduction - Set all values =0
TO SOFTEN THE SHIFTS AT LOW RPM:
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 1->2 - All positive values =*.5, all negative values =*2
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 1->2 - Subtract 20 from entire table
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 2->3 - Subtract 30 from entire table
I've been monitoring pressure and force motor desired current but haven't been able to figure out how to soften the shifts. I'm going to try to play around with shift times and see what happens. If all else fails, I'll turn on torque reduction for the lower torques.
PERFORMABUILT, are you suggesting that age/wear could cause a harder or softer shift?
In my case, I've messed around with several things, but not getting the effect I'm looking for. Here's what I've done:
TO KEEP IT OUT OF PANZY MODE:
Transmission - Disable Abuse Mode
Transmission - Set RPM, TPS, Speed =0
Transmission-Torque Reduction - Set all values =0
TO SOFTEN THE SHIFTS AT LOW RPM:
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 1->2 - All positive values =*.5, all negative values =*2
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 1->2 - Subtract 20 from entire table
Transmission-Shift Properties-Shift Pressure Modifier-Upshift 2->3 - Subtract 30 from entire table
I've been monitoring pressure and force motor desired current but haven't been able to figure out how to soften the shifts. I'm going to try to play around with shift times and see what happens. If all else fails, I'll turn on torque reduction for the lower torques.
PERFORMABUILT, are you suggesting that age/wear could cause a harder or softer shift?
Well of course they can. But the main point I am making is that a firm shift is not nessesarily a bad thing as long as its not teeth rattling,
firm equals longer clutch life. less heat and wear.
soft or sliding equals more heat and wear from the slipping of the clutch, Soft equals slipping clutch thats how the soft shift happens.
This is the whole reason a shift kit is installed which makes harder shifts to reduce slipage in the clutches and bands
firm equals longer clutch life. less heat and wear.
soft or sliding equals more heat and wear from the slipping of the clutch, Soft equals slipping clutch thats how the soft shift happens.
This is the whole reason a shift kit is installed which makes harder shifts to reduce slipage in the clutches and bands
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If you have the corvette servo and the harsh shift is intermitant and second only. Try this,
Remove the corvette servo. Remove the metal plate from the large side. Grind four notches in the place deep enough to amke four small openings past the retainer ring.Reinstall the plate and servo , This make help.
Sometimes fluild will become trapped behind the plate in a sort of hydraulic lock and eliminate the cushion springs affect. This can cause and intermitant slam shift from first to second and this mod can help
Remove the corvette servo. Remove the metal plate from the large side. Grind four notches in the place deep enough to amke four small openings past the retainer ring.Reinstall the plate and servo , This make help.
Sometimes fluild will become trapped behind the plate in a sort of hydraulic lock and eliminate the cushion springs affect. This can cause and intermitant slam shift from first to second and this mod can help
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My main concern is wear and tear on the drivetrain. This has been my daily driver for 7 years; most of which has been spent shifting it manually (becasue as it came from the factory, it would hit the rev limiter HARD from 2-3 and 3-4 if I let it shift itself).
In my case, the shift form 1-2 is pretty hard even at 10% throttle. Putting it into gear from park (rpm is 800 when cold) shakes the car pretty hard; even with the below changes:
Transmission - Enable Abuse Mode
Transmission-Abuse Mode- Set RPM =2000, TPS =15%, Speed =50
Transmission-Abuse Mode-Torque Reduction- Set all values back to STOCK
Transmission-Torque Reduction-Normal - Set all shifts =20 up to 120 lb/ft torque
I know that I had a mis-calibrated MAF (I've done a lot of work on the stock induction pieces and the MAF is now lying about the amount of air coming in). When I turn the MAF back on (setting the fail freq. back where it belongs), I noticed that the PCS Desired current is about 50% higher than with the MAF disabled (from .780 with the MAF off to 1.2 with the MAF on). Any idea why that would be?
When the desired current is at 1.2, the shifts are nice and smooth.
In my case, the shift form 1-2 is pretty hard even at 10% throttle. Putting it into gear from park (rpm is 800 when cold) shakes the car pretty hard; even with the below changes:
Transmission - Enable Abuse Mode
Transmission-Abuse Mode- Set RPM =2000, TPS =15%, Speed =50
Transmission-Abuse Mode-Torque Reduction- Set all values back to STOCK
Transmission-Torque Reduction-Normal - Set all shifts =20 up to 120 lb/ft torque
I know that I had a mis-calibrated MAF (I've done a lot of work on the stock induction pieces and the MAF is now lying about the amount of air coming in). When I turn the MAF back on (setting the fail freq. back where it belongs), I noticed that the PCS Desired current is about 50% higher than with the MAF disabled (from .780 with the MAF off to 1.2 with the MAF on). Any idea why that would be?
When the desired current is at 1.2, the shifts are nice and smooth.
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Verdad Gallardo Well if your case I think you are certainly dealing with some odd tuning issue . The MAF does affect the trans performance. Though the mod I listed may help a little on the low throttle shifts, I think you are going to have to keep playing with the tuning which I am no expert at .
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This thread solved MY problem: https://ls1tech.com/forums/pcm-diagnostics-tuning/707511-hard-1-2-shift-sd-mode.html
Transmisison Diag-Max Line Pressure DTC- Set all 3 to disabled
When the system sees a MAF failure (DTC P0101, P0102, P0103), it sets max line pressure, which overrides all other settings, it appears.
Transmisison Diag-Max Line Pressure DTC- Set all 3 to disabled
When the system sees a MAF failure (DTC P0101, P0102, P0103), it sets max line pressure, which overrides all other settings, it appears.
