'01 Trans Am
4l60E
Circle D 3800
HPT 4.0.x
Experiencing issues shifting in my '01 TA. 4L60E, Circle D 3800, rebuilt 300+ miles ago. Fluid and temp are fine. Have been making changes and regardless of what is done I cannot get the 2-3 shift to work. Continues to bounce off the rev limiter. Able to get 1-2 ironed but no go on the 2-3. Suggestions? Much appreciated.
Shift Attempt 2.hptPoints 2.hpl
'05 GTO E40
'01 TA
I think you should start logging some trans and converter slip data.
its an internal issue most likely with pressure falling off at higher rpm so cant make the shift. Or that 3-4 drum is possibly cracked. I build for a living and run 4l60e in my 07 Tahoe with an lsa blown 5.3 on 14 lbs and its 6500 lbs truck so much harder on it then if was 3400 lbs and 800 plus hp. I also run them in my 850whp turbo firebird and a 94 z28 with a 392 stroker that turns 7800 rpm. Takes some special internals to get them to live and shift right in extreme conditions and live. PM me if have other questions or to tell me on the build as I fought the 2-3 for a long time in my 1994 as shifting it at so many rpm and kept burning it up.
First 9 second 6th gen lt4 zl1 stock blower SHC SBE boost only.
2013 cadillac ats 2.0t Big turbo-gone
2007 tahoe 5.3 lsa blower on 14 lbs boost 6l80e swap 2009 os
2017 zl1 a10 big gulp/2 inch headers/ 9.55 lower/ e85/bigger hx /103mm tb / Synergy trunk tank and underhood kit/methanol injection with torqbyte controller and prometh pump / Jokerz performance R&D ported stock blower/ lme cnc heads /GP tuning custom cam. So far 9.30@150
Thanks for the info. Trans has been completely gone through and only 300 miles on it. I do have the build sheet with the parts installed but not readily available in the office. Hoping it is a tuning issue, here is what I currently have the shifts set at: Shift Info.jpg
As far as logging pressure and converter slip data, I will see what PID's are available for the car. If there is anything in particular that would be good to log let me know. I have another points race tomorrow afternoon so will continue to troubleshoot the 2-3. Another bit of info is that during the shift the RPM's do not drop down very far. Maybe about 500 rpm's when the shift is finally made.
Found a thread from LS1TECH that another user found the lowering the shift MPH down to either zero or 2 was the key to making his trans shift.
https://ls1tech.com/forums/pcm-diagn...ear-issue.html
"Ok well a local tuner helped me out. I tried to adjust MPH all over and it didn?t work. He told me to zero out the MPH. It worked. It now shifts to third at WOT."
""Thats great but that doesnt always work , I find setting 1-2 shift at 5 mph and the 2-3 shift at 9 mph and depending on the flash stall, you can usually fine tune it to your desired shift points.""
Adjustments didn't remedy the shifting issues at the track. After the gates closed there was a gig on the street so figured attempt to lower the MPH down extremely low. Changed 1-2 @ 5mph/2mph and 2-3 @ 9mph/6mph from 94% TPS to 100%. Made a hit and the car actually shifted. Crazy. I will need to go back and adjust the normal shift time and up the RPM and limiter. For now, lowering the WOT MPH to 5 and 9 is working. Next points race at the track in two weeks so will be able to get a true final(?) test during the dial in passes.
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