4L80E Transmission tuning question
03-07-2008, 10:48 AM
#43
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With my TransGo kit I see a 200 to 400 difference in programed shift RPM , meaning if I command 5200 shift RPM it will shift at 5400 or 5600 WOT but PT (below 90% TP) shifts at commanded RPM .
Think that has something to do with the Shift Kit , line pressure and time it takes the PCM to command the shift .
Think that has something to do with the Shift Kit , line pressure and time it takes the PCM to command the shift .
03-07-2008, 11:24 AM
#44
Interesting. So, its not just me. You and Thuder550 have had the same issues. I am gonna wait until I get home and load this new tune and see what she does. If it fixes it, then I can adjust the shift rpm up until I get it where I want it.
03-07-2008, 03:15 PM
#45
I have been following this thread closely as I have very similar problems with my 80E. I do not have much valuable input because I do not have tuning software.
BUT... First, my trans with the HD shift kit shifts super hard even though my tuner has reduced a lot of the shift firmness. Second, when my truck downshifts from 2-1 at WOT, it will almost always hit the rev limter. When I take off in first, it is usually fine.
BUT... First, my trans with the HD shift kit shifts super hard even though my tuner has reduced a lot of the shift firmness. Second, when my truck downshifts from 2-1 at WOT, it will almost always hit the rev limter. When I take off in first, it is usually fine.
03-07-2008, 03:57 PM
#46
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I have been following this thread closely as I have very similar problems with my 80E. I do not have much valuable input because I do not have tuning software.
BUT... First, my trans with the HD shift kit shifts super hard even though my tuner has reduced a lot of the shift firmness. Second, when my truck downshifts from 2-1 at WOT, it will almost always hit the rev limter. When I take off in first, it is usually fine.
BUT... First, my trans with the HD shift kit shifts super hard even though my tuner has reduced a lot of the shift firmness. Second, when my truck downshifts from 2-1 at WOT, it will almost always hit the rev limter. When I take off in first, it is usually fine.
Yeah haven't really figured out why the TransGo kits do that but that is what I see also , seems the trans kit overrides the PCM and shifts off pressure .
Hope that helps !
03-07-2008, 04:47 PM
#47
Hard shift is from to large of hole in valve body plate , reduce the hole to .076 instead of .096 and it will be much tamer (have the tranny shop that did it do it) , then tune with software for desired firmness .
Yeah haven't really figured out why the TransGo kits do that but that is what I see also , seems the trans kit overrides the PCM and shifts off pressure .
Hope that helps !
Yeah haven't really figured out why the TransGo kits do that but that is what I see also , seems the trans kit overrides the PCM and shifts off pressure .
Hope that helps !
Sorry to hijack your thread.. 1slow.
03-08-2008, 06:53 AM
#48
No worries man. I have the same 1-2 hard shift. I have adjusted everything trying to get rid of it. I even hooked up a pressure gauge and ran it in the cab and drove around logging actual fluid pressure.
From what I have been told we will have to pull the trans, flip it upside down and pull the pan. I guess if you do it in the ruck the check ***** can/will fall out and its a bitch to get them back in right. Next pull the seperator plate and basically shot peen (hammer) the hole closed as much as possible and then re-drill with the smaller drill bit. Easy fix but a lot of labor and time.
If anybody else knows a better way I'm all ears.
From what I have been told we will have to pull the trans, flip it upside down and pull the pan. I guess if you do it in the ruck the check ***** can/will fall out and its a bitch to get them back in right. Next pull the seperator plate and basically shot peen (hammer) the hole closed as much as possible and then re-drill with the smaller drill bit. Easy fix but a lot of labor and time.
If anybody else knows a better way I'm all ears.
03-08-2008, 09:17 AM
#49
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No worries man. I have the same 1-2 hard shift. I have adjusted everything trying to get rid of it. I even hooked up a pressure gauge and ran it in the cab and drove around logging actual fluid pressure.
From what I have been told we will have to pull the trans, flip it upside down and pull the pan. I guess if you do it in the ruck the check ***** can/will fall out and its a bitch to get them back in right. Next pull the seperator plate and basically shot peen (hammer) the hole closed as much as possible and then re-drill with the smaller drill bit. Easy fix but a lot of labor and time.
If anybody else knows a better way I'm all ears.
From what I have been told we will have to pull the trans, flip it upside down and pull the pan. I guess if you do it in the ruck the check ***** can/will fall out and its a bitch to get them back in right. Next pull the seperator plate and basically shot peen (hammer) the hole closed as much as possible and then re-drill with the smaller drill bit. Easy fix but a lot of labor and time.
If anybody else knows a better way I'm all ears.
Yep shot peen the holes and re-drill , or buy a new plate about $20 and re-drill smaller holes (forgot , the new plate would have to have a couple of places blocked off) , what I use is a "drift" because of the flat end and tap it firmly a few time and then check the hole to see if it reduced in size .
I to apologize to DC_Justin and BlackGMC , did not mean to take over thread .
Last edited by HD6.0l; 03-08-2008 at 09:30 AM.
