4L60E 1-2 shift in drive is weak
#1
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4L60E 1-2 shift in drive is weak
Car is a 33K mile 2001 Formula, recently installed a Yank SS3600 that works great. When in Drive (or 3rd) at WOT it does not shift hard at all. If you manually shift 1-2 at 90% throttle at 4000-5000 RPM it shifts firmer.
No mods to transmission except Tune and I trust the guy. We have other LS1 auto cars that shift extremely hard and I want this one to do it too. On the 2-3 shift mine is firmer. I am open to suggestions to pass to my tuner.
One of our other cars has a Yank SS4000 and slams 2nd gear. And this convertor (SS3600) which we bought new slammed 2nd gear in the other car I had it in first. The convertor only has 500 miles on it from new.
So any suggestions, do I just need a few parts/servo/adjustment? Strange to me that manually it is firm but in drive it is just normal.
No mods to transmission except Tune and I trust the guy. We have other LS1 auto cars that shift extremely hard and I want this one to do it too. On the 2-3 shift mine is firmer. I am open to suggestions to pass to my tuner.
One of our other cars has a Yank SS4000 and slams 2nd gear. And this convertor (SS3600) which we bought new slammed 2nd gear in the other car I had it in first. The convertor only has 500 miles on it from new.
So any suggestions, do I just need a few parts/servo/adjustment? Strange to me that manually it is firm but in drive it is just normal.
#2
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The 2-4 band could be getting weak/worn...proper way would be to go in there and replace it along with the sunshell
Or, you "CAN" drop the pan, check the 2-4 band clearance with valvebody off, extend pin to tighten clearance, also remove 1-2 acc. housing , replace stock plastic 1-2 acc. with aluminum unit and STIFFER 1-2 spring, do not block it off....all this can be done with trans in the car...If the separator plate is in good shape, open up the 2nd gear feed hole to .090 and the 4th feed hole to .120
you will get a better 1-2 for sure...
Also want to add that MAF being dirty fro K&N oil can jack with transmission pressures, make sure its clean
Or, you "CAN" drop the pan, check the 2-4 band clearance with valvebody off, extend pin to tighten clearance, also remove 1-2 acc. housing , replace stock plastic 1-2 acc. with aluminum unit and STIFFER 1-2 spring, do not block it off....all this can be done with trans in the car...If the separator plate is in good shape, open up the 2nd gear feed hole to .090 and the 4th feed hole to .120
you will get a better 1-2 for sure...
Also want to add that MAF being dirty fro K&N oil can jack with transmission pressures, make sure its clean
#3
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Brad, you know you know me, Aarons dad. Will you be at the track tmro, we'll be there. I know its possible, but with the low miles I doubt anything is worn out yet. If you have ideas pass them on to Shane please.
Last edited by 79TAKid; 10-23-2012 at 11:51 PM.
#4
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I have seen more broken shells, output shafts from harder 1-2 shifts vs just a nice bump...Thats how I setup the Rams 60E, just a good 2-4 band, and stiffer acc...shifts smooth at part throttle then a bump at WOT , hasn't missed a beat with even the nitrous hits.
Shane is very good with the trans tunes, I have talked to him before about what my builds would like as far as trans pressures and shift request times.
If you dont want to pull the trans and still want a bump on the 2nd gear shift the 1-2 acc. springs I have on hand for my builds work great with that aluminum piston..easy to install
#5
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silverz28camaro's advice is of course spot on.
You might also want to replace the seals in the servo. (I understand getting the servo out is difficult in your car).
GM often used a plastic piston in the 1-2 accumulator; it can crack, leak and make the 1-2 shift sloppy.
You might also want to replace the seals in the servo. (I understand getting the servo out is difficult in your car).
GM often used a plastic piston in the 1-2 accumulator; it can crack, leak and make the 1-2 shift sloppy.