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I am looking to swap my 98 Chevy and have a rh47, I wnat to keep my push button t case which is a np243 will the rh47 bolt right up to it, and what will I have to do to make the speedo work?
 

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Well, that would be a place to start as well as people who make adapters, or look for a damaged on in a wrecking yard. GM has a lot if commonality as well as Chrysler, each in their own kingdom, so look extensively! Making up special splined shafts is a little awkward as well as replacement issues. Special adapters are not so complicated.

Many use GM trans., although none are as diesel friendly as torqueflites.

Ed in CO
 

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The input shaft spline count on the NP243 must be matched to the output on the 47RH. Then you run into input shaft length issues, because the NP243 needs to be clocked on the 47RH via a clocking ring, "shafts are not built to be used with clocking ring, so a longer shaft would need to be machined down to work in your configuration. The speed sensor output on the 47RH needs to be calibrated to GM speedo via a stand alone controller, the NP241 had a speedo output, on the rear case extension, with no need to convert dodge to gm speedo signal. Images are of a NP241c adapted and clocked to a 48RE OD unit.
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There were 2 different 241C transfer cases depending on what transmission they went with. The TH350, 700R4, and 4L60e used 27 spline input and the heavier transmissions used 32 spline. The Dodge 48RE (A618) has a 23 spline output so I don't see that matching without an adapter.
 

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Did the 241c and 48re splines match up, or did you have to make up special shaft? If they matched up, then that would be the way to go for Noa if he can stand a computer on the re!

Ed in CO
NO match, just determine the right spline count for the application.. The next issue is the thickness of the gear on the adapter be it thin or wide and the gear tooth pitch and width, finally machining for length.
I used the 23 spline shaft in the GM t-case to match the 48re.
 

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There were 2 different 241C transfer cases depending on what transmission they went with. The TH350, 700R4, and 4L60e used 27 spline input and the heavier transmissions used 32 spline. The Dodge 48RE (A618) has a 23 spline output so I don't see that matching without an adapter.
Later 4L80 series used the 32 spline shaft, that is what was in my truck.
 

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So, did you machine down a 32 spline shaft to fit the re spline count?
Ed in CO
Nope, I installed a long 23 spline used in the Dodge NP241 DLD w/short bearing race...then measured it, remove it and machined its length to fit my application.
 
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