TH400 shifter issue

[65chevysub]

Good Morning. My 84 Sierra is having an issue with the shifter. About a month ago, the clip on the rod to trans yoke broke and I couldn't shift into Drive. I put a new cotter pin in it, but now my shifter wants to keep jumping into Neutral on it's own. I've tried several times to adjust the rod that goes to the shifter but it keeps jumping into Neutral while driving so i have to rest my arm on it to stay in Drive. Is there something I overlooked? I'm trying to avoid going to a trans shop if it's something I can fix.
I've enclosed a couple images of the rod to shifter connector and the rod to the yoke at the trans for reference.

[65chevysub]

Other 2 images

[65chevysub]

I forgot to mention there were no issues prior to the clip breaking. Shifting was good, and the shifter stayed in Drive while driving. Fluid and filter were replaced a couple months ago.

[AussieinNC]

Suggest you check the rear trans mount has not broken allowing the trans to move around...

[clinebarger]

Originally Posted by AussieinNC

Suggest you check the rear trans mount has not broken allowing the trans to move around...

X2....Check the engine mounts too.

[65chevysub]

I just put a brand new Energy Suspension trans mount in about a month ago. I'll check the engine mounts next.
Thanks guys