put it in reverse count to ten before it moves 102 thousand miles
That’s an interesting statement. I don’t think I have driven anywhere near 102K miles in reverse.
1st stab at the cat a trans fluid and filter service.
Even if the OP doesn’t own a cat, I strongly recommend a trans fluid/filter change.
Even if the OP doesn’t own a cat, , No one own’s a cat the cat own’s you as I can atest to.
A 10 year old furrin’ car I owned only took a count to 5 to go into reverse.
As if you didn’t know it, the transmission is on it’s way out.
Three options: Find a good transmission shop and have it fixed, Shop for another vehicle, or, Live with it until it doesn’t go in reverse -or- drive.