Which bolt to remove to check oil level in transmission

[Iowaboy]

I have a 50 B2B, 4 speed manual transmission with fluid drive. I want to drain the trans and refill to correct level. On the passenger side of the case there are two 9/16 bolts that look like refill ports. One is about two inches above the other, which one is used to check and refill the trans gear oil level.

I have looked in the shop manual, no help. 

[Merle Coggins]

The pipe plug that angles up, just behind the PTO cover, is the fill/level plug

 

[Iowaboy]

Thanks. I did see that fitting. It has a recessed square in the end. I assume I add the gear oil until it overflows.  

 

[greg g]

While it out, paint it yellow for the next time.

[FlashBuddy]

Great idea!