Offroad Trailblazers and Envoys

Transfer case swap

Dumping ground for offroad Trailblazer or Envoy general discussion.

by NSBEAST21 » Sun Oct 01, 2023 8:20 pm

Hey looking for info on swapping my nv226 transfer case over to a np231c anyone with details is very helpful entirely
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by dirty anton » Mon Oct 02, 2023 10:48 pm

Check out Advance Adapters they help me out. I got a ring reluctor kit that went between the transfer case and the transmission and got my speed sensor from that.
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dirty anton
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by xXxSilveradoxXx » Tue Nov 14, 2023 10:39 pm

The NP231C swap should be quite easy. You'll need a transfer case adapter off of a 1500 series truck that had the 700R4 or the 4L60-E to convert the NV's 5-bolt transmission coupling to the NP's 6-bolt. Input shaft spline count should be the same since our NV is mounted to a 4L60-E and the NP was mounted to a 700R4. Both transmissions had the same spine output shaft (27-Spline if memory serves). Output shaft on the NP has a speed sensor. I would bet that if it wasn't the same spline count as the NV's, the NV's reluctor wheel would swap over. If it doesn't, a custom reluctor wheel could be made, or you can modify the count with an ECM flash. Only issue would be mounting a shifter, but that shouldn't be a deal breaker.
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