first differential fluid change
 

Just changed out the Differential Fluid and got some interesting notes. I originally bought just a 1 qt bottle of royal purple 75w-90 but couldn't get the last bit out the bottom of the bottle cuz of the tight space near the fill plug. Unfortunately the auto shop only had lucas oil and noone near had RP and I had no other ride with me. Bought a qt of Lucas oil which a mechanic recommended to me (15 bucks from them), it is a very thick, syrupy oil that's in a white bottle. It doesn't list a weight on the bottle (i.e. 75w-90) and only thing it says on the bottle really is made to smooth gear boxes.

So pretty much i put in 80% RP 75w-90 and 20% of this lucas oil and notice immediately that there's no more "buck" when changing gears! I had a smile on my face for the first couple miles from the relief.

Someone there who was waiting in line for the lift had mentioned the lucas oil as it sticks to the gears unlike royal purple which will just form a pool below the gears. Also, from what I've been told, they will not make a "water and oil" liquid conflict. Was really skeptical and was actually going to just drain and buy 2 qts of RP 75w-90 to prevent possible damage but so far I might just have to hold out on that thought.

So for anyone wondering if changing out the rear diff. fluid is a good idea I have to say that it is. :D

Not really sure if you can go 100% lucas oil though as it doesn't say anything about LSD additive. Any thoughts?

Put RP in mine yesterday. We were able to get the whole bottle in just took a little hose on bottle end and squeezing. For sure worth it though.

You guys ever think about turning the bottle over and allowing to drain to the tip, cutting the bottle 2/3rds the way down and filling the remainder?

If you ar worried about dirt, cover the top with a sandwich bag or saran wrap and a rubber band.

Great ideas! I will try this tomorrow when I do mine. I also bought the LSD additive since i didn't know the RP already had it in. So, if I run short, I'll just add that :)

Well, Hi, I am trying to change my differential fluid and don't seem to have the correct Allen or Torx heads. Can you please let me know what size they are and if the drain size is the same as the fill plug?

Thanks!

Ok, got it! Thanks guys! it was the end of the 3/8" ratchet! Torque: 24 lbs. My service guy had also gotten back to me. Easy change to do, even with the Zoomer's exhaust!

Thanks again!
Michael J.

You may want to go look at this

http://www.bobistheoilguy.com/images/lucas/lucas.htm



.

interesting read but it sounds like it would be good to use 100% lucas oil so it sticks to the gears and not trap air or just stay away from the Lucas oil all together?

I have noticed smoother transitions though after switching gears. Maybe the 80%RP and 20% lucas was a good mix? :iono:

Might end up changing out to 100% royal purple depending on replies

Edit: actually nvm, just read some posts on how RP and Lucas are lower rated gear oils. I'll be changing out the diff. fluid tomorrow with Amsoil when I find a store with some.

Anyone know what stores sells them? Seems like autozone and napa don't carry Amsoil

You can buy AMSOIL right from their web site and have it ship UPS to your door in a matter of a few days.

Synthetic 75W-90<---Have in my CTS and GMC
or
Synthetic 75W-110

Just a word on gear lubes. Use the 75W-90 Severe Gear Lube from Amsoil. Been in my Camaro since 2000 miles. Would not use anything else for FREE and would pay double for Amsoil. It is worth that much. That is how I became an Amsoil Dealer is using the gear lube back in 1981. A friend brought over 2 quarts to me. It was the only gear lube on the market that would quiet a 514 posi from chatter in a built '70 Monte Carlo. I was so impressed with the 80W-90 back then that it totally amazed me. It said 20 to 50 degree temperature reduction on the bottle. You could literally feel the difference putting your hand on the dif. I seen a guy at a tractor pull 6 months later with an Amsoil hat and flyers in his pocket and he did not have to say a word. Whatever they had I was trying it. They have FANTASTIC products.

PS. Amsoil sticks to gears like honey.

ps. Lucas oil is GARBAGE!!! The Lucas Oil sponsored Top Fuel Team doesn't run Lucas Oil even though they get it for free:sm0:

Thanks, thats all I needed to hear,will be putting it in my diff and tranny this week!

high horse power cars need to step up their game with good synthetic fluids:

http://www.amsoil.com/StoreFront/images/svg_350pxh.jpg



And if you are running high horse power, cams, exhaust, intake and tunned:

http://www.amsoil.com/StoreFront/images/svo_350pxh.jpg