First, Honda did not mak a "750" Goldwing. In 1976 the Goldwing was a 1000 cc machine known as the GL1000. As for transmission fluid, the 1976 GL1000 does not use transmission fluid. It has a wet clutch, and the engine oil provides all the lubrication that the clutch and transmission requires. For this reason it is extremely important to use the correct engine oil and change it at regular intervals. For detailed information check out www.randakks.com.
There is no dipstick on this bike. Instead, there is a sightglass on the right side of the crankcase. You may have to use a flashlight to see the oil level through the sightglass. With the bike on the center stand, the oil level should be around the middle of the sight glass "window". Some people have made their own dipsticks to use in these bikes.
I use Motul 10w40. Check with your local dealer.
No
Honda does not require Synthetic oil for the Goldwing. So it's up to you. BTW: I have never heard of a wing dying due to an oil related problem. Mine is still running strong at 110,000 miles changed every 8k per Honda.
Yes, it is. However, there is separate gear oil in the final drive of the Goldwing, as it is shaft driven.
There is no dip stick on these models. So, with the bike on the center stand, start the engine, look down around the foot brake area, you will see a little window with a screw in the center, that's the place. Use a flashlite and have someone turn off the engine, you will see the oil settle. The level must be in between the lines.
same as the engine oil
My owners manual for my 1984 Honda GoldWing says to use SAE 10W-40 Oil.
Honda does not require Synthetic oil for the Goldwing. So it's up to you. BTW: I have never heard of a wing dying due to an oil related problem. Mine is still running strong at 110,000 miles changed every 8k per Honda.
15W40
GL 1000, 5 speed, with clutch. The engine oil is all you need.