Network sync problem

Hi! I have two different player prefabs, they are tanks, first is T90, second is Abrams, they use same scripts with little bit different values. And now I have problem, only second player prefab have problem with sync.

There syncing code:

 function OnSerializeNetworkView (stream : BitStream, info : NetworkMessageInfo) {
     if (stream.isWriting) {
         pos = transform.position;
         rot = transform.rotation;
 
         stream.Serialize(pos);
         stream.Serialize(rot);
     } else {
         stream.Serialize(pos);
         stream.Serialize(rot);
 
         transform.position = pos;
         transform.rotation = rot;
 }

I tried a lot of things, like equal all scripts values of second player prefab to first and etc...

After long debugging I figured out two things: 1) In Update script I wrote next code:

 if (network.isMine == false) {
     Debug.Log(transform.position - pos);
 }

So I get next results, first player prefab gives me zero vector what means perfect sync, but second player prefab gives me (0.0, -0.5, 0.0), (0.0, -0.3, 0.0) etc.

2) If player prefab lie upside-down on terrain the problem goes away.

P.S. Sorry for bad language.