My 2005 S-type is making a weird sound when the gear shifts to 4th but 5th is fine and I sense a burnt smell when this happen. So when I did a little research I understood that this can be due to worn out clutch pads but for my car other gears shifts fine. So I am wondering if this could be wear or just solenoid timing issue or any other? Is there any way to confirm the issue without actually taking the transmission out?
Any relevant information is much helpful I cannot afford thousands of bucks to fix this.

Thanks

 

You can get at the clutches etc from beneath, without taking the trans out.

I can't say if you need to do so.

 

Is it possible to that worn out clutches can cause bad shift only for 1 gear?