545RFE shoppingg

I'll be shopping for a 545RFE or 65RFE for the auto trans to replace the 5-speed manual trans for my eventual 56 Dodge pickup build on my 2001 Dakota 4.7/RWD chassis. Shopping on CL and FBM makes it easy to find a lot of used trans, but many of them are for 4x4 chassis. My truck will be RWD only.

So if I buy a 545RFE or 65RFE with the transfer case attached can I simply remove the transfer case and install the u-joint for the driveshaft? Or is there an additional end cover/seal I have to use to convert a 4x4 trans to a 4x2 RWD trans?

Also, the build will require a new/custom length driveshaft when I get to that point. Should I use steel? Aluminum? Carbon fiber? My primary goal for the build is to create a totally modern and current/new chassis under my 56 pickup so it will be as "new" as a brand new truck for a LOT less money than buying a newer used truck.

most 4x4 transmissions with the transfer case attached have different output shafts than the regular transmission, so you would have to tear the 4x4 transmission apart and install the output shaft from a 2x4 transmission, as well as the 2x4 tail shaft and any other related parts.
at least that was the case with my experience with early [up to the mid 80's] transmissions in my junkyard ownership days.
i would say it's still the same today, or close to it.

The full sized Ram 4x4 to 2x4 transmissions were the same up through at least 2012. Had to change the output shaft (requires complete trans disassembly) and then install the rear drive tail shaft and whatever else was needed there.
You would probably be better off to spend the extra money to buy a rear wheel drive trans.

That's exactly what I need to know. So I will only shop for a 545RFE or 65RFE transmission from a RWD chassis. Thanks for the replies.

According to this it appears to be just a tail housing swap in the case of 4x4 to 4x2? https://www.yumpu.com/en/document/view/39531308/converting-a-dodge-45rfe-4x4-transmission

A post here seems to back up this claim as well. https://www.ramforum.com/threads/545rfe-transmission-questions.83751/

and this one as well. Not sure how accurate but, here is one last one post from another forum: https://moparforums.com/forums/f18/545rfe-differences-18325/

that's certainly interesting.
i would have thought you would have to change out the output shaft.
it's too bad there isn't a "short" tailshaft available that would allow an easier conversion in certain applications. [maybe there is ?]

I was thinking the same thing as well. Too bad an 8 speed wouldn't work easily with the 4.7L application just for the purposes of the torque multiplication.

I agree. If the newer 8-speed trans were mountable to the 4.7 I'd go for it. Better acceleration and gas mileage. But a 545REF or 65RFE basically have two overdrive ratios for highway driving so its still better than 5th gear with my current 5-spd manual trans. When I install the 4.7HO and 545RFE in my 56 Dodge pickup build I'll have to get a driveshaft made for it so the tailshaft length of the trans is not an issue that way.

I'll also have the option of going to an aluminum driveshaft or some other drive shaft options.

Have you throught about the 66rfe? Better first gear than the 65 and they share a bunch of parts with the diesel 68rfe.

Actually, based on the data shown in this video, the ratios for the lower gears is actually better in the 545RFE.

https://www.youtube.com/watch?v=GIEz_yWtQDk

Its worth a view.

The donor chassis for my 56 Dodge pickup is my 2001 Dakota with the 5-speed manual. When I change it over to a 545RFE automatic, what will I have to change chassis wise? Harness? Connections at the instrument panel? Controller? Connections to other systems? I plan to keep the floor shift console, use a Lokar or American Shifter to control the trans. I already have a different instrument cluster with the shift indicator.

I answered on the truck section thread.

I added a reply to the truck section as well in addition to his. I wasn't sure if I mentioned a couple of things but, it's there.