Factory vs built trans tune differences
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
Factory vs built trans tune differences I have an oem 4l60e with a yank 3200ss converter. The car was tuned when the cam and converter was installed. There is nothing wrong with the trans currently. I plan to install a procharger soon so I doubt the trans will hold up very long.
My question is... If I install a built 4l60e trans and reuse the same converter am I likely to have any tune issues transmission wise? If so what are some possible issues?
My question is... If I install a built 4l60e trans and reuse the same converter am I likely to have any tune issues transmission wise? If so what are some possible issues?
Your built trans will not require any tune but you may need to have the converter restall for the pro charger. Then and only then, you may need a re tune as well for the pro charger and the stall.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Your shift points may need adjustment, as the built trans will likely shift a bit earlier (this was my experience - quicker shift times with less slop led to earlier actual shift rpms at WOT.) But, you'll likely want to adjust shift points anyway with the new setup.
You also need to be careful with the trans pressures. if the shop that builds the trans increases the pressures mechanically and the tune already jacks the pressures up, you could end up with too much trans pressure.
TECH Junkie
Joined: May 2012
Posts: 3,048
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From: Poplarville, MS
Like ddnspider said. Trans pressures can be raised with the tune and most "built" 4l60e transmissions have a larger boost valve installed that raises line pressure up into the 220 psi. range. As you can see installing a transmission that has a larger boost valve into a vehicle that has had the line pressure jacked up with the turn will put the line pressure dangerously high.
I usually suggest putting the pressure settings to stock if they have been changed, If the PCM was already tuned for the converter and shift point I do not think you will see or need to make any changes there .
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Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
My 1/2 light throttle got harsh with my upped pressure settings and HD2 kit. I knocked them down maybe 20% and it was fine. Everything else remained the same.
