Changing diff fluid..

**ls1fan74** · 06-13-2009, 04:26 PM

Anyone have a how-to on this? Sorry if it seems like a newb question but I searched and found some threads on "what fluid to use" but not actually HOW to do it.......it's prob ridiculously easy for most of you but this is my first RWD car and I haven't done one before.

**JB454** · 06-13-2009, 06:17 PM

Originally Posted by ls1fan74

Anyone have a how-to on this? Sorry if it seems like a newb question but I searched and found some threads on "what fluid to use" but not actually HOW to do it.......it's prob ridiculously easy for most of you but this is my first RWD car and I haven't done one before.

Make sure you use the additive for limited slip differentials! Besides that, use a good synt fluid recomended for your ride.

**cammed goat** · 06-13-2009, 07:20 PM

I changed over to AMSoil 75-140 Severe Gear and was good but a few days later my diff developed a low-speed chatter. I bought a tube of CRC True Gear diff additive and the chatter is gone now. Feels alot better.

**ls1fan74** · 06-13-2009, 07:22 PM

30 mm? day-um thats a big one....ok so that's it? 15 mm open and let it drain out, then plug it back up and open the 30 mm, add 3 quarts of 75w-90? I'm upstate ny...its pretty warm right now, I'm stock and drive fairly agressive not too bad though. Should I go heavier? (80w140?)

**CompSyn** · 06-14-2009, 03:03 AM

75W-110, or 75W-140 is a better rout to go as some have differential chatter issues with the 75W-90; a little too thin in some applications. Also, AMSOIL Severe Gear already has limited slip additives in it, but some do end up needing more. AMSOIL Slip Lock™ Differential Additive is compatible with the other additives in Severe Gear.

CompSyn

**Sarge** · 06-14-2009, 03:19 AM

Let me find a pic of my diff and I'll do a quick write up with some arrows for you....

**Sarge** · 06-14-2009, 03:21 AM

Hells bells...Ol RedGTO beat me to it....
http://www.redgto.com/KB/article.asp...7&cNode=5U4I3A

**ls1fan74** · 06-14-2009, 10:13 AM

that.is.awesome. thanks a bunch thats a huge help..i may do the trans fluid now too

**ls1fan74** · 07-03-2009, 11:28 AM

can i get this friction modifier from the dealer?

**Spikito** · 07-03-2009, 12:03 PM

I was gonna help but your rear end is way different than mine. I have one plug, on the side of the housing, above the axle. Only way to drain is to either pump it out, or pop the diff cover.

**ls1fan74** · 07-04-2009, 06:15 AM

No prob....I think I'm gonna go with mobil 1 from the auto parts store and that trans-x friction modifier....I'll leave it in for a bit, if i start to hear noise (theres none now...purely maintenance) I'll order some amsoil.

**Texas Jack** · 07-05-2009, 04:29 PM

ls1, Got mine at the dealer ship it is P# 43161, but make sure the bottle inside the wraper has 7089 on it. I used RP and really didn't have to use any but just for insurance used 1/2 oz. Just to let you know it smells like hell and use rubber gloves. Jack

**Sarge** · 07-05-2009, 05:40 PM

No shit...I think we should drop about 4 oz of that shit on them towel head sons bitches...they quit right there and join the Catholic Church....man that stuff STINKS!

**Texas Jack** · 07-05-2009, 06:12 PM

It's freaking nasty shit!!!

**ls1fan74** · 07-06-2009, 04:59 AM

umm is there any downside to too MUCH friction modifier? if there is such a thing?

**Sarge** · 07-06-2009, 10:49 AM

The modifier makes your lube less slick so your diff will engage in lockup (posi traction) so you are diluting your lubes ability to be slick....

**Hi-Po** · 07-06-2009, 06:38 PM

Dealership prices on the lube is way expensive. Evn the parts guy told me to go buy it from Chinazone,

And yes, it stinks badly. I honestly wear gloves anymore. Hate that smell.

**ls1fan74** · 07-08-2009, 02:29 AM

yea i ended up spilling some on my hands as well as the tarp i'd put down to work. then i rolled onto it, so it got my shirt too. I put about i'd say 4-5 oz of trans-x in before I filled the diff..too much? should I change it again?

**JAX04** · 07-08-2009, 09:07 AM

i used 75w 140 ROYAL PURPLE, it already had the friction modifier in it. and i used two quarts, gm said to fill it to the bottom of the fill whole. lol you cant fill it more then that. lol. i think my diff is alot smoother now with the RP. nice stuff.