LSD differences

[HMNGSupraMKIII]

Hi, I have a 1989 Supra Turbo. I'm getting a whining noise from the rear and I'm thinking its my differential. I'm thinking of picking up a differential from a 1987 Supra Turbo but I don't know how its gonna affect the car. I know the gear ratio in the 89 is 3.73 and the in the 87 is 3.91, but i don't know how its gonna affect the car or which is better. So I need input if putting the 87 differential in my car would be a good idea. Thanks

 

[Midwest_Mudder]

your speedometer is going to be off, youll gain a bit of acceleration, your RPMS at say 60mph will be higher. if you understand what the rear end gear ratio refers to it gets pretty simple to visualize whats gonna happen. right now your driveshaft spins 3.71 times for every 1 turn of the tire, with the new rear end itll spin 3.91 times for every one turn. its not always one is better, obviously the lower ratio will give you more top end. its all about what you want/need out of the car

as for the whining, i doubt its the actual LSD, possibly a bearing somewhere, but doubt its the actual mechanism. id drain the diff, and refill with a good gear oil w/ lsd additive in it before you take any large leaps. could be low

you dont have 4wd so it wont HURT anything, just be different. drop the entire pumpkin so you dont have to reset the ring and pinion