DEAR CAR TALK: I recently bought a gently used Toyota RAV4, and passed on my 2000 Honda CR-V with 189,000 miles to my grandson. One day while he was driving, it developed “a loud banging noise right under me.”

He drove it a few more blocks. The U-joint at the front end of the drive line broke completely off, and the yoke was slightly damaged.

The tech at the shop said we could pay $65 to remove the drive line and support brackets, and turn it into a front-wheel-drive-only car, or pay $1,000 to order and install a new drive line. He assured me that everything would work fine, and since Junior doesn’t drive in snow or mud, I took the $65 option.

After about 1,500 or so miles, the car started having all kinds of issues: not wanting to get going after stopping in traffic, and not wanting to get out of first gear. One guy told me it’s the transmission; another told me to put the drive line back together and the problems would go away. What do you think? – Grandpa Jess

RAY: I would guess it’s not related to the front-wheel-drive battlefield conversion you did, Jess. Which is too bad, because then the Magic 8 Ball points to the “transmission.”

On some cars, you really can’t convert them from all-wheel drive to two-wheel drive. But this CR-V is really a front-wheel-drive car at heart. They added a viscous coupling in the rear that activates only when the front wheels are going faster than the rear wheels (like when the front wheels are slipping on ice).

So if you remove the rear drive shaft, it’ll simply never activate. So that shouldn’t affect your transmission. But 189,000 miles followed by a young, lead-footed grandson can affect a transmission.

My advice would be to go online and look at mechanicsfiles.com. That’s a database where readers and listeners of ours recommend mechanics they really like and trust. You can search it by ZIP code. And you can and should look for someone who specializes in Hondas.

It could be a bad transmission control module, a bad range sensor or a stuck valve or obstruction somewhere. Someone who works on a lot of CR-Vs may have seen this problem before, and may have a sense of whether it’s more likely to be something mechanical or something electronic.

He may want to try a transmission-fluid flush first, just in case it’s a stuck valve, since a flush can free it up. That certainly would be the best-case scenario, Jess.

But once you get a better handle on what’s causing the problem and what it’ll cost to fix, you can decide whether you want to repair it … or let Junior hoodwink you into kissing that gently used RAV4 goodbye. Just don’t give him a transmission warranty this time, Jess. Good luck.

Got a question about cars? Email Car Talk’s Ray Magliozzi by visiting the Car Talk website, www.cartalk.com.