Hi, I am new to posting but I have been doing a lot of searching and research concerning this. Anyway, I know a lot of guys are running aussie lockers. I just ordered one for my 89' pickup (rear). It seems like most people run a heavy gear oil once its broken in to keep it quiet. I have narrowed my choices down the redline shockproof heavyweight or amsoil severe 75w110. Anyone have any experiences with these oils or care to make suggestions? If it matters I live in New Mexico where the temp might be 115 in June and then 10 in december. Thanks for answering.

 

DON'T USE REDLINE SHOCKPROOF WITH A LUNCHBOX LOCKER!!!!!!!!!!!!!!!!!!!

It sounds good on paper- thick, cushioning, claimed temperature stability, "250W" film strength, BUT in reality it does not work. Maybe it doesn't have the proper viscosity of slipperiness to work with lockers. The locker jerks and clacks like you wouldn't believe with *Heavy* Shockproof.

Do yourself a favour and buy some good mineral oil (not synthetic) in a 80W140 or something like that. Its cheaper and because of the weight it will protect the gears just fine. It also quiets and smooths the locker down a lot.

Just trust me. I've tried lots of oils with my Aussie.

 

Where are you located in New Mexico?

 

Hey, matt, why not synthetic? Just curious?

Is it just the price difference or what? just wondering, since i have all new bearings and seals, so i was going to use some synthetic, but if its not that much of a difference in protection, then ill just get some valvoline since its like $5 a quart

 

Junkers88, I am in Alamogordo (Holloman). Matt, Thanks for the reply. Just curious, have you tried the amsoil at all. I will take your advice, I just wanted to know what you didn't like about it.

 

i have always heard that full syn gear oil is best in the rears due to it does not breakdown like conventional oil due to extended heat and friction.

 

Mostly cost. As oils break down, they become thinner. If you were running straight a 80W, even they smallest bit of oil degradation would cause trouble as you are left with maybe a 75W oil due to the oil molecule shearing.

80W140 is suitable for commercial trucks use (think dumptruck), so it offers amazing protection, whether mineral or synthetic. It is overkill for a diff on a 4000lbs vehicle.

With mineral oil in such a high weight, you get protection, and it smooths up the locker, all for $15/ 4 qts.