Just picked up a 94 400l 4x4 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....

 

Could be front chain/eccentric related that you might want to check out.If chain is too tight or loose,bearings in the eccentic housing worn,can do this along a worn cv joint or u-joint popping when in reverse.Joints can wear even it the boots are not damaged.Plus another common thing is for armature plates in the hubs to magnetize and stick causing pulling to one side.
Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse
Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse