I just bought a 2005 Suzuki Vinson a few months ago and was gonna change the oil in the front and rear Differential. My question is what weight oil should I use? Ive been looking online and havent been able to find anything on it

 

90 weight gear lube should be fine.

 

Just make sure it has a GL-5 rating.

 

I changed mine using Honda gear oil

 

the manual states to use SAE90w hypoid gear oil with a GL-5 rating. if you operate under 0 degree temps to use SAE80w hypoid gear oil.

i changed mine with a synthetic 80w140 gear oil. if you use a regular SAE 80/90 weight oil, be sure to add some friction modifier to the front diff for the limited slip. i found some 80w140 Valvoline synthetic at advanced for $12/qt so that was just as good as ordring the high dolor stuff from summit or jegs!