JK hemi swap and 8 speed transmission
02-17-2023, 07:59 AM
#1
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Join Date: Feb 2023
Location: tyler, tx
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JK hemi swap and 8 speed transmission
I performed a DIY JSS hemi conversion on my 2007 6 speed JK unlimited in 2021-2022. It works great, but since then there has been a lot of talk about 8 speed transmissions. I used a 2008 5.7L from a RAM with the 545RFE transmission. Does anyone have first hand experience with the 8hp70 or 8hp45 matching up with the 2008 5.7? I have emailed Todd at JSS, but havent heard back. Thx in advance!
my conversion required converting to an automatic.
my conversion required converting to an automatic.
Last edited by jacobpac; 02-17-2023 at 06:16 PM. Reason: Additional info
02-17-2023, 01:23 PM
#2
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I do know that with my Chev LT 2016 conversion with 8 speed auto that the auto cannot be used with the LS series engine. As crazy as it may seem the 8 and 10 speed autos use a different throttle pedal than the 6 speed which both LS and LT had behind them. The LT with the 6 speed uses a different pedal than the LT with 8/10 speed. I believe there may be similar issues with the Mopar V8's or if you could fit them together then you are looking at some serious changes. The new transmissions work on the torque requirements altering the settings the motor runs on especially virtual VE and timing changes. All to do with emissions. There are technical guys on the internet that take questions on brand specific issues so you may want to reach out to them.