last week i did my rear brakes changed the oil. an decided to change the rear diff oil on the drive. if i use a lower rating oil than suggested is that bad. because after i ride it for 10 mins it either make a noise or bad squeaks. i went for a ride recently and it made noises than stomped for the last hr of riding. now yesterday it made a different noise. but after it sat i asked my dad to look at it drive it etc to see what it was it made no noise. i drove it hard as well too see if the noise would appear. any ideas?

 

Don't know much about an ozark but could the oil be leaking into the brakes? Lower weight oil probably wouldn't hold up very long and probably wouldn't keep the gears from touching and wearing. Also lower weight oil might leak out of the seals onto the brakes.

 

what are lower weight oils i think i uesd sae 75-90

 

That doesn't sound bad to me.