K9crew Posted March 3, 2004 Share Posted March 3, 2004 Since buying my '99 LS in November I've been less than thrilled with the shifting strategy so I've been experimenting this past week. Normally I start the engine, put the shifter in D (transmission has L, 2, 3, 4 and D) and for the most part leave it there all the time (not if I want to go backwards :) ). The problem is that if I'm driving in traffic around 15 to 20 mph (stop and go) with the shifter in D the car tends to surge i.e. I'm braking then I get back on the gas and nothing happens for a second or two, then it feels like something engages and I surge forward. If I'm on the freeway doing 60 mph and I want to accelerate around another vehicle I press harder on the gas and for about 2 seconds nothing happens then suddenly the transmission downshifts and the power comes on. For the last week or so I've kept the transmission in 4 and only shifted into D when I'm cruising on the freeway at 60mph. My conclusion is that the car drives so much better that way. It's considerably more responsive for general driving such that when I need to accelerate the performance is immediate vs. a significant delay if I'm in D. The surging sensation in stop and go traffic is non-existent if I keep the transmission in 4 vs. D. I'd really appreciate some feedback in terms of how you drive your car and have you experienced any of what I've described. Thanks to 99lsguy and 1990LS400 for listening to my PM ramblings. I'm in your debt. :) P.S. Even though these transmissions are supposed to have "intelligence" they aren't the sharpest tools in the shed. As far as I'm aware, the Allison transmission found in the Silverado is one of the few transmissions that approaches the driving capability of a manual i.e. it downshifts automatically in turns or when descending steep grades. Quote Link to comment Share on other sites More sharing options...
99lsguy Posted March 3, 2004 Share Posted March 3, 2004 k9, I've always left in in D an off I go...............but I drive EASY. I would agree there's a little lag. I'll experiment with your procedure :D Your attention to detail is appreciated - no stone must remain unturned! 99 Quote Link to comment Share on other sites More sharing options...
K9crew Posted March 3, 2004 Author Share Posted March 3, 2004 99, Thanks for the input and for offering to help. 1990LS400 raised the issue of the torque converter locking and unlocking. Does anyone know when, in what gears or under what conditions the TC locks up? I had an F-150 that would lock the TC in 2nd, 3rd and OD if the vehicle's speed was above 35mph. The Tundra has a similar strategy. :) Quote Link to comment Share on other sites More sharing options...
SW03ES Posted March 4, 2004 Share Posted March 4, 2004 Have you tried driving in ECT PWR mode in D? I always found that got rid of the hesitation on my dad's old 98. Quote Link to comment Share on other sites More sharing options...
VMF Posted March 4, 2004 Share Posted March 4, 2004 i drive on 3rd in the city, car is much more responsive when i need sudden acceleration. as to the D.. in my case its same as 4th and this power/etc button doesnt do anything. i mean it does raise the rpm bar for shifting but same thing happens when you push the pedal to the metal. tranny uses same logic in both ways. Quote Link to comment Share on other sites More sharing options...
98 LS Posted March 4, 2004 Share Posted March 4, 2004 I really enjoy the "Snow" setting when I'm in the mood to drive very smoothly around town and in stop and start conditions. It also reduces the "Surge Effect" many folks have described. When driving through the park on winding roads I downshift manually and use 2nd and mostly 3rd since the Big Lex will just roll and pickup speed so easily in "D" on a downhill. On the highway I use the "Power" setting since it more rapidly downshifts to "4th" and produces the desired results. Quote Link to comment Share on other sites More sharing options...
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