Uhh, that's what the modifier dose, changing the friction and flow characteristics of the 90w to keep the friction discs cleaned and lubed. I've seen a lot of synth use and never any damage related to it's use. Some synth dose not have the LS additive you have to watch for that.

This is the first I've heard of this. Can you tell me which ones and when? GM has recommended it's use in G80 truck axles for years, FoMoCo offers a synth 75w140 for their axles And Chrysler also supports it's use.

The oil will foam regardless It has a high detergent content and is being agitated at high speeds pumping air into the oil creating foam. Slipping clutches allows you to turn with ease not foam the oil, most of the vehicles direction of travel is straight where the LS is not as active.

Some synth oils have the additive in it, some don't. the additive is compatible with synth oils.

Well, he did not say he was topping it off nor did he state whether he measured the oil he lost. He would not have been able to collect it all and measure it, third rule of mechanics "a little oil goes a long way". So, don't worry about the 3qts thing. It is possible to overfill a diff if you're using a pneumatic pump. Iffy lube sucks them out and pumps them full, at least around here.

 

The posi unit is a Eaton LSD and from the website it says its a clutch style...so you're probably right! So what kind of oil should I put in the rear end?

Nope. I might have used a "jk" and "lol" at the end if I was . I'm no car expert, which is why I came to the forum looking for incredible answers from you guys

Thanks for clearing things up for me. So, does it always stay open? Because that's where the oil is coming out from.

Oh it does? Well then, so I probably lost about 2 qts

Good to know. It hasn't done any of that...yet.


So it looks like all I have to do to fix this little problem is change the type of oil? Any oil recommendations? Thanks for all the help!

 

"Iffy Lube"....heh heh heh!
But still, if you were seeing an amountable oil loss every day for 7 days, wouldn't you check the level? I would. He was painting a picture of an eruption, not a dribble. Ok, I guess we can't presume the guy was immediately following up on an obvious problem. Let her go dry, then it won't leak!

 

Man, I'm getting quote overload! Just use conventional, non-synthetic gear oil, with the LSD additive. Yes, that vent stays open, it's supposed to be able to breathe to compensate for internal heat expansion.

 

I gotchya, I would also check the level, if I felt the fluid loss was sufficient enough to be a concern.

Sorry bout the joke thing, I was not sure how to take this thread, since it leaned more towards the qwick-to-crew-you lube places bad rep.

 

Off the subject, 78 those seats look pretty comfortable, where did you get them?

 

Camaro and 350 thanks for your help . Looks like I'm going to have to drain my rear this weekend. Yay me!

I purchased the seats off a website called Hyperformance. The seats are super comfy. However, the seat bracket for the sliders didnt line up with the camaro configuration so my dad and I had to make a custom adapter...which was a B$!&% to do.

 

Eaton (what 78 has) says to use conventional non-synthetic oil. So does Auburn: FAQ « Moser Engineering