It would not be much more expensive to just replace the reverse bands and put it back in. As long as it still shifts nice, I would just do the reverse and reseal the front pump. As long as you change the fluid religiously every 30k, stick with it.

Otherwise the used tranny you put in is a crap shoot 16k from now. If your reverse gave out at 190k, you really want to risk only 50-80k before it needs to come out again with the used one? Your tranny could last up to 300k assuming everything else shifts nice other than the reverse issue.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k