Need Some Advice For Ol' Allis

I'm doing a lot of much needed maintenance and work on my FTP 6024 forklift ( S.N 1645 1000 who has affectionately been given the name Ol' Allis. She's an oldie but a goodie and my hopes are to give her many more years of life and a useful purpose as opposed to being junk yard art which is what she was when I brought her home over 10 years ago. My year and a half ordeal of repairs and upgrades all started with a leaking tilt cylinder and a steering cylinder that was weeping a bit but I am confidant that anyone who has owned and worked on old machinery that belongs in The Smithsonian Institute can appreciate, things are just never easy or simple. This has turned from a patch up to a labour of love but the old girl has certainly been faithful to a fault and earned some lovin'. I am about ready to drive her off the hoist and out into the sunshine and to back to work but I am in need some advice on some issues which need attention before she can go back into the fray, as it were.

Yesterday, as I near the end of my mini overhaul, I went to check the differential oil. I was laying on a creeper under the machine which is raised about six inches to allow me to get under her with a creeper as she sits on my four post hoist, I removed the bung ( threaded plug ) that is on the rear of the differential case and found myself frantically struggling to stem the flow of gear lube that came gushing out onto myself and the floor. After losing all of a gallon of lube, I got the plug back in which leads me to my question of where is the place where one checks the diff oil level and adds oil if needed? Obviously, I am now going to have to add lube but I have been unable to find the place on the housing where I do this.

More questions will be coming and any help or advice will certainly be appreciated.

Thanks for the smile. Man, can I ever identify with that guy in the background during the first several seconds. I can laugh about it today but I weren't doin' a lot o' gigglin yesterday. Kinda felt like Jed Clampett for a bit there.

I went out and looked at that diff and I can't see no way to replace the oil that was lost. I hope that someone has some answers.