1994 400l 4×4 issue

Just picked up a 94 400l 4×4 last night, already have a 95 sportsman so figured it would be pretty similar.

Has one issue I cant figure out. It will go into 4 wheel drive just fine. Problem is if i back up then go forward while its in 4 wheel drive its like the right front wheel is binding up, pulls really hard to right and will pop and bang from driveline until I turn off 4 wheel drive stop and backup up then go forward again.

Checked fluid in front hubs, both seem to engage and diesengage just fine. Totally stumped….