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Hello all I am a newbie and need some help/advise. I recently threw a rod bearing on my 2000 Civic EX (Auto). Had a lot of miles on it so bought a re-man motor. Dropped in the new re-man motor and now I am getting a humming sound from my transmission. It doesn't matter if in park, reverse or drive. As the transmission get closer to shifting point the humming gets louder until shift then it get quieter. Before I swapped motors there was no issues with transmission. Any help would be greatly apperiated.

Thanks
K