jdcamaro99

i need some opinions on what gear oil to run in my 2001 SS. I just had 3.90's installed a few weeks ago. I'm almost at my 500 mile break in period. I was wondering what gear lube to put in when i drain the oil.?? I keep reading different things on conventional and synthetic. I read that Amsoil SG 75 110 is the way to go. I also saw to not use synthetic and go the conventional route to cushion the rear a little more since i still have the tiny 7.5" 10 bolt. What do you guys recommend?

Firebrian

There are lots of old posts on this topic to read through. Just do a search of this forum section for "gear oil" or something similar. A quality oil either way and you should be fine. If you're going to track or race the car then a synthetic might be better to keep temps down. The Auburns need conventional fluid.

https://ls1tech.com/forums/search.php?searchid=28458625

Per the rear axle sticky:

You can find this in the owner's manual. Otherwise, 75w90 or 80w90 will work fine. It is not necessary to use synthetic oil. Also if you have an auburn carrier you will need the limited slip additive.

dailydriver

I use a 75W-140 from any of the following companies; Amsoil SVO, Red Line, L.A.T., Valvoline Synpower, Motul, or Millers CRX/NT.

I use the 140 weight only because our 10 bolts are SOOOO over-stressed, and overwhelmed with power/torque (especially in a manual car), and think that it needs ALL of the help it can get to deal with the shear, and impact put on such a small ring and pinion.
I feel this outweighs the added heat/friction, and VERY VERY slight power and MPG losses over a 75W-90, or even a 75W-110 (which is really just an updated, slightly thicker, 75W-90).

What differential is in your car, as either you, or the original owner had a choice of diffs from SLP when ordering the car??

jdcamaro99

I'm not sure what is in it to be honest. I'm assuming whatever came stock that year in 2001. I'm the second owner and the previous owner didn't have too many things done to the car. I would expect it to just be a stock rear.
I do take it to the track every so often. Not an every weekend ordeal by any means. But i like to take it up there and run it a few times a year. I was just reading debates on synthetic versus conventional. It is so teeter totted though. I kept gettting torn in different directions on what to actually go with. I saw a good break down by "Sarge" and the clear victor was Amsoil 75 110. The 140 does make sense though for a soft cushion. So that led me towards redline shockproof. But then i read on it that it can gel up in cold temperatures. I'm in Pa, so not cold cold temps like Canada or anything, but it can get brutal here at times.

Thanks for the info/help guys.

allmotor1

I use 75w-90 non synthetic in my moser 12 bolt with friction modifier

01ssreda4

iTrader: (96)

You dont need anything but 75/90 dino oil. Meaning buy the cheapest **** you can find and roll with it. Your rear doesnt need any special oil.

SteveC

I use straight 140W dino oil, along with the LSD additive.

I am not a proponent of synthetic gear oil.

No problems whatsoever everything nice and quiet.

dailydriver

The Red Line Shockproof is really for spooled/NON limited slip cars ONLY since it has much moly in it, and that will cause both friction plates, or cones to slip too much, or even worm gears to not grab against the case and bias correctly.

You really cannot go wrong with Amsoil's SG 75W-110/140, but, if you want to save some coin while still running a full synthetic gear oil, the Valvoline Synpower on sale at NAPA stores this month is just a hair less of a fluid (is actually BETTER in some areas) than the Amsoil fluids, and will still flow very well in our Pennsyltuckey winters due to it's decent viscosity index.

jdcamaro99

Thanks for the comments guys. Appreciate the help.

RockinWs6

I use the Amsoil Severe Gear 75-140, dam good gear oil.

blackandgold

iTrader: (2)

I'm running schaeffer 80-90.

jdcamaro99

do you still run the additive with this? Or do you just roll with the additive that is mixed already?

dailydriver

Depending on your diff, you could just try it with the Amsoil SVO by itself, and IF you have NO chattering, or moaning/groaning on low speed, sharp turns (like pulling into a parking space/coasting around a 90* turn slowly), do not add any modifier.

IF you do, add 2 ounces at a time until it goes away, or if you do not want to bother with all of that, just add the full 4 ounces right away, the choice is yours.

I ALWAYS had to add at least the full 4 ounces of a l.s. friction modifier (even the potent Motorcraft XL-3!), to stop the Eaton Posi's low speed turn groaning/squawking, even in gear oils which claim to have the additive already in them, but YMMV.

jdcamaro99

good stuff man. Thanks.

RockinWs6

I'll be honest I can't remember what the 01 SS came with Torsen or Auburn carrier? But if you have the Auburn you CAN NOT use synthetic oils, It will ruin it in short time. Ask me how I know................

Easy way to tell is jack up the rear in the center wheels off the ground, leave car in gear or park. Try to turn either wheel, if its a torsen they will turn easily. If its Auburn they will not turn without a lot of force.

01ssreda4

iTrader: (96)

99 and up all got Torsen with one exception, SLP did install Auburn diffs in a very select few SS cars that were optioned with it.

paradigmGT

Is anyone here using the regular Amsoil 75W-90 Synthetic Long Life Gear Lube (FGRQT)?

Also do you need to add friction modifier to any of the Amsoil synthetics?

SSCamaro99_3

iTrader: (1)

Yep, AAM cover is a dead giveaway. My 99 SS is actually a non T-top cloth interior car. Do not see many like it.

paradigmGT

Took a pic of my rear diff, would you guys be able to tell me if it is a Torsen or Auburn? '99 Camaro SS 6MT, cloth interior but with T-tops.

dailydriver

That is very good stuff, but, if you are dropping that much coin already, why not just 'step up' to the Severe gear series, or even the Valvoline Synpower which is just as good, if not better??

Like I said before, with my Eaton Posi I ALWAYS had to add 4 ounces even to the Severe Gear which claims to have the FM already in it.

I would put it in and drive it, then IF you get any noise, or clutch/cone pack 'symptoms', add 4 ounces in after.

(IF you definitely have a Torsen T2 in your axle, you should not need any FM, even though the dealers were given a TSB about adding it to these to quell the 'rocks in a box' coast down/off throttle noise.)