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| 4T60 + Performance Shift odd behaviour http://www.pontiacbonnevilleclub.com/forum/1992/topic14034.html |
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| Author: | repinS [ Fri Sep 04, 2009 2:55 pm ] |
| Post subject: | 4T60 + Performance Shift odd behaviour |
I hadn't really used Performance Shift since getting the car, so I can't attest to how well it works. Today though, for *shoot* and giggles, I decided to try it out for fun. I notice that I get TC lockup in 3rd gear with performance shift ON, at about 40mph. I don't get it when it is off - for the past year I've been getting my normal 1-2-3 shift, 4th at 40mph on light throttle, and then TC lockup at 48-50mph. It seems kind of backwards for "performance" sporty driving, generally you wouldn't want lockup when you're pushing it. Is that normal? Should I be getting 3rd gear TC lockup all of a sudden when I turn on Performance Shift? It *is* a fresh rebuild. |
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| Author: | alec_b [ Mon Sep 07, 2009 4:17 pm ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
My guess it more likely that you're hitting lockup at 40 no matter what, performance shift or not, and that the performance shift just holds 4th gear out longer. My understanding is that the performance shift really only raises shift points a few hundred RPM anyways, so my best guess is that you're feeling lockup and just think it feels different because you haven't gotten much chance to use the performance shift. Drive it around for a week and see if it doesn't start to feel more like the regular normal program. |
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| Author: | repinS [ Tue Sep 08, 2009 12:07 am ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
There doesn't appear to be torque converter lockup with Normal Shift on when I hit 40mph. Never was, before or after rebuild. Any twitch of the throttle and the revs change freely as if it were unlocked. And no, it's not slipping. After driving around for a couple more days, when I have Performance shift on, I will see full TC lockup at 40mph, but it won't be until 53mph that it will shift into 4th, with the TC still locked. In sequence: NORMAL SHIFT Stopped 1-2-3 shift, TC unlocked Shift into 4th gear @ 65km/h (40mph), TC unlocked TC lockup @ 48-50mph This is how I've driven the car since getting it a year and almost 20,000 miles ago, and it's been like that both before and after rebuild. It's only now that I actually bother to play with Performance Shift: PERFORMANCE SHIFT Stopped 1-2-3-shift TC lockup in 3RD gear @ 63km/h (39mph) Shift into 4th gear @ 85km/h (53mph), TC STILL LOCKED (even during shift) I thought the 4T60-E never had lockup in 3rd? |
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| Author: | GoldenBullet [ Tue Sep 08, 2009 12:14 am ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
Ive had a similar experience Jerry. I know mine wouldn't lock up in normal at ~38 mph but does in performance shift. I will do some testing to see if the same thing happens still, I haven't had it in normal shift in a long time so I don't remember. |
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| Author: | repinS [ Tue Sep 08, 2009 12:18 am ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
Thanks Matt. I'm not sure if either scenario is proper, because in Normal shift I'm not getting lockup, and in Performance shift it's locking up at lower speed. Seems counter-intuitive to a "Performance" mindset. FWIW, when I have normal shift on there is NO illumination at the button. The button lights up for Performance Mode. |
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| Author: | RJolly87 [ Tue Sep 08, 2009 7:42 am ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
It was my understanding that when it was set to performance mode, it will shift like any other 4T60-E driven vehicle, and when in normal mode, it backed off on the shifts. With that being said, under easy acceleration, this is what mine does: 1st gear to 10mph 2nd gear to around 20mph 3rd gear lockup happens before 40mph, I am thinking it is before 35, but this is verified by just barely nudging the brake pedal and feeling the revs go up 4th happens around 48mph, lockup unknown. |
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| Author: | Jrs3800 [ Tue Sep 08, 2009 8:58 pm ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
Most 4T60-E's through 1995 will hit lock up at 36 Mph in 3rd gear with light load.. All 4T60-E have Lock up in 3 Gear.. Actually all THM440-T4's( 4T60 ) and all 4T60-E's as well as 4T65-E's have 3rd gear TCC Lock |
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| Author: | GoldenBullet [ Tue Sep 08, 2009 9:50 pm ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
Just went for a drive and had the exact same results as Jerry. No TCC lockup in third at the normal 38ish mph in normal shift although it does in performance shift. |
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| Author: | RJolly87 [ Wed Sep 09, 2009 7:47 am ] |
| Post subject: | Re: 4T60 + Performance Shift odd behaviour |
Jrs3800 wrote: Most 4T60-E's through 1995 will hit lock up at 36 Mph in 3rd gear with light load.. This is actually spot on. I verified it this morning |
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