I'm working on my 63 Dart GT that's getting a 5.7 Hemi. It's getting to be transmission time and was wondering what is the best way to go? I have heard guy's using 4L65E's, NAG's, 727's, how about the 545RFE's ??? They bolt up to Hemi's, actually have 6 speeds (2nd Prime), what's the down side?
545RFE Pros & Cons
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dgc333
Well-Known Member
The 545RFE is a 4speed tranny with an alternate 2nd gear. It shifts through 4 gears with the choice of second gear controlled by the computer.
You have to do serious surgery to the tunnel to make the 545RFE fit and will need to use a factory computer to run it.
It would likely require less surgery and electronically it is much easier to use an A518/46RH. It bolts to the hemi with a spacer between the crank and flex plate. Only the OD is electronically controlled and that can be as simple as a switch or can be operated automatically with a home grown circuit or an aftermarket module.
You have to do serious surgery to the tunnel to make the 545RFE fit and will need to use a factory computer to run it.
It would likely require less surgery and electronically it is much easier to use an A518/46RH. It bolts to the hemi with a spacer between the crank and flex plate. Only the OD is electronically controlled and that can be as simple as a switch or can be operated automatically with a home grown circuit or an aftermarket module.
Max340
Well-Known Member
The 45RFE is the fourspeed variant that has 1,2,3,4, and has a 4, -> 2.5, downshift/kickdown. The 545RFE is a true fivespeed AT, with two OD ratios, rather than one.
If I understand this trans correctly, it could be fairly easy to set up electronic shifting for driver operation. However, if the car is already getting a 5.7 Hemi, its possible to use the original TCM, since it would plug right in to a stock engine management system harness. ALso, its worth noting that the 545RFE and the Allison trans used in the Chevy trucks are all but indistinguishable from one another in cutaway view, since they are very similar design.
If you go with the 4L65E, be sure that you can set up the electronics for the shift. Also, be sure its a 4L65, not the 60, as the 60 is prone to frying the OD clutch. Having built the 4L60E, I'd opt for the Mopar trans prior to putting the GM in any of my cars. The upside to the GM trans is that the shift design is progressive use of the elements, downside is those elements may not hold a lot of power. Get the Corvette version if you choose to go this direction.
If I understand this trans correctly, it could be fairly easy to set up electronic shifting for driver operation. However, if the car is already getting a 5.7 Hemi, its possible to use the original TCM, since it would plug right in to a stock engine management system harness. ALso, its worth noting that the 545RFE and the Allison trans used in the Chevy trucks are all but indistinguishable from one another in cutaway view, since they are very similar design.
If you go with the 4L65E, be sure that you can set up the electronics for the shift. Also, be sure its a 4L65, not the 60, as the 60 is prone to frying the OD clutch. Having built the 4L60E, I'd opt for the Mopar trans prior to putting the GM in any of my cars. The upside to the GM trans is that the shift design is progressive use of the elements, downside is those elements may not hold a lot of power. Get the Corvette version if you choose to go this direction.
Stacked360
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I was wondering about this very topic, I'm putting a 2005 5.7L out of a 300C in my 73' duster, and wanted to go with a 545RFE, instead of the NAG1 (because it shifts to smoothly) I am going to be running a high rear-end gear ratio so the steep overdrive ratio is very attractive to me. The questions I need answers to are:
1. Will my 2005 hemi from a 300C plug into a trans harness for the truck transmission?
2. My motor has the MDS package installed, will the 545RFE support it? (not sure if they offer it in trucks)
3. Just how much...surgery are we talking? I am willing to make room for it but, no tunnel bump like in F-body camaros:angry7:
Tough questions but I thought I would post here :-D
1. Will my 2005 hemi from a 300C plug into a trans harness for the truck transmission?
2. My motor has the MDS package installed, will the 545RFE support it? (not sure if they offer it in trucks)
3. Just how much...surgery are we talking? I am willing to make room for it but, no tunnel bump like in F-body camaros:angry7:
Tough questions but I thought I would post here :-D
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