tranny options

Just pulled M47; It had a weird noise, a grinding in first and second. Thought it was a throwout bearing but it but it was good. . Backing up here.

I repaired (M47) reverse gear about a month ago. After I repaired it, I reinstalled it and it performed great but developed and grinding noise going down the road. Just in first 2 gears; at a certain RPM. The tranny shifts great. I popped the cover off of it tonight but all seems good. Now Im stumped. Pilot bearing good. Carrier bearing good.

I dont want to put this tranny back in. So heres my options. I have a good m46 with everything I need to install it but it has 250000 miles on it. When I changed the fluid, it came out black. But the tranny seems solid.

Next option, I have a auto. with less than 100000 miles on it. Works great, shifts a little hard but seems solid. I have everything to make the swap. But?????

Just looking for advice.

Most people upgrade to a T5. Or swap with a good M47 if you can find one and only if you're not looking to increase HP

Hey, I figured out the grinding noise. It is the stupid carrier bearing. When I spun it under the car it seemed fine. Last night I pulled the driveshaft off and got it on my bench, pulled the rubber off of it. Then gave the bearing a whirl, first time seemed fine. But 2 or 3rd time it made a grinding noise. So M47 is going back in. Thanks for the help everybody.

What threw you off was that it was only in the first two gears. You would expect a bad carrier brg to complain in any gear.