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Old 11-22-2004, 09:09 AM   #11
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I had no idea it would be benificial to leave the tranny in drive for that, I thought that it was bad for the tranny to leave it in drive when over 45mph.
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Old 11-22-2004, 04:34 PM   #12
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This "hunting" you talk about.. is it when the tranny is slow to shift? Mine isn't slow, but when WOT in 1st, shifting at redline to 2nd [manually], it is very harsh. Not to mention before I put in some transtune, it would take like 5 seconds to down shift, manually.


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Old 11-22-2004, 06:28 PM   #13
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hunting refers to when the car doesn't know which gear to be in, so you get a constant upshift/downshift/upshift, and repeat.
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Old 11-22-2004, 09:41 PM   #14
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The 2000+ models with the 4T65E HD are different too.
If you leave it in 3rd or drive, it will shift at wide open throttle at a lower rpm than if you leave it in Drive which is really Overdrive.
Best to just leave it in D.
1,2,3,D,N,R
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Old 11-23-2004, 01:39 AM   #15
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in my car manual for my 91 le it says for best feul economy it is best to keep it in od all the time
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Old 11-23-2004, 11:26 PM   #16
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Quote:
On most of the NA'd 4T65-E'* isn't the torque converter applied at varying degrees to reduce slip and improve the fuel effiency?
You must mean the lock up feature of the torque converter. There is a clutch pack in the torque converter that effective locks it up so it acts like a direct connection between the engine and the rest of the drivetrain. It is electronically controlled.

A non lock up type of torque converter, like in my TurboHydramatic 350 that my Firebird has, will always slip a little, about 3-5% slippage at higher speeds.

When a lock up type locks, the rpm will drop noticeably, like going into a higher gear, improving fuel efficiency.
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