Knocking sound with manual trans

[70CHRG]

I have a 1970 Dodge charger 440 RT with a 4 speed manual trans. Driving it home yesterday I noticed a knocking noise when accelerating in second gear. The knocking got faster as I accelerated and slowed down as I did. All other gears seem fine. Any suggestions where to start looking. Anywhere I can get info schematics of these transmissions.

 

[493 Mike]

I have a 1970 Dodge charger 440 RT with a 4 speed manual trans. Driving it home yesterday I noticed a knocking noise when accelerating in second gear. The knocking got faster as I accelerated and slowed down as I did. All other gears seem fine. Any suggestions where to start looking. Anywhere I can get info schematics of these transmissions.

It sounds like you have already diagnosed your issue.
Mike

 

[70CHRG]

It sounds like you have already diagnosed your issue.
Mike

Not yet. I guess its inside the trans. Is it likely to be a bearing or gears. I've never had one apart before. I haven't had the car for long and my understanding is the first and second syncros were done not long ago. When I strip it down is it likely to be obvious. Appreciate any thoughts.

 

[493 Mike]

When you pull it out, rotate the input and feel for the issue in second gear. Then pull the side cover and look for tooth issues.
Mike

 

[AR67GTX]

Kind of hard to figure out what could make noise in 2nd gear only but a damaged drive gear tooth is about it. I would order a factory service manual for your car from one of the Mopar parts dealers. Summit has a CD version for cheap but I like the hard copy versions better.

Bishko Automotive Literature 1210 Bishko Service Manual DVDs | Summit Racing

 

[gkent]

Keep in mind that every gear is free-spinning with the cluster at all times. Only when a syncro sleeve is moved does the particular gear lock to the main shaft to drive the output. The fact that its second gear only is strange but my guess would be another syncro not fully disengaging and the teeth are still in contact.