Just bought a used f-150 w/ 265k miles, changing all the fluids and considering this for the rear diff since it's on sale for $5 a quart at AZ, the price is right just curious about the quality.

Anyone used this in the past or have any thoughts either way?

Castrol Syntrax Limited Slip gear oil SAE 75W-90 32 oz.

 

IF that lube meets the specs for your truck then it should be OK. Most any Major brand name will do that.