TORCHD 02 TA

iTrader: (39)

I had a couple questions.

1) Do i want to put a bead of rtv silicon (black) down with a new gasket?

2) How many qts of gear oil do i need?

3) what weight is recommended? my car is not a DD see maybe 2,000 miles a year

4) What brand? I have seen Valvoline and maybe Mobil 1

5) Syn fluid or regular fluid?

6) for my 2002 Trans Am do i need the friction modifier? How do you know if you do not need it

7) Do i need to re torque the bolts or just nice and snug.

sorry for all the questions. I have done a search and got mixed result from people

Thanks

Z28LS1camaroguy

iTrader: (3)

if u wana put silicon then thats up to you for added seal but the gasket should be fine. Usually bout a quart will do just fill it up until you can stick your pinky in the hole and feel the fluid, and synthetic would be a good idea. as far as bolts should tighten them down pretty good and snug, but tighten down in a sequence evenly each time and you will get a good seal.

Black_Bird

iTrader: (6)

You can use a gasket or just silicone alone, I've always used silicone and never had a leak. Holds around 1.5 quarts, just buy 2. Synthetic, 75w90 is what I've done. Some nice brands (Amsoil, etc) have the limited slip additive built in, if it doesn't then you can buy a small bottle along with the gear oil at the store. Fill it up until it starts coming out of the fill hole, let it get even with bottom of the hole then put the plug back in. Sticking your finger in to check level is not a good idea for the most part, you want it extremely clean inside and as soon as you do it any dirt, contaminants, etc on your finger(most likely going to have dirty hands since you're under the car doing this) are now inside the housing. Space tightening the bolts out and snug them down.

TORCHD 02 TA

iTrader: (39)

I was going to buy 2 qts no syn (prolly valvoloine), go with 75-90 or 85-90 gear oil, get the LSD additive and go with black silicone and a gasket

vjo90rs8

iTrader: (9)

1) Do i want to put a bead of rtv silicon (black) down with a new gasket?
I used a new Felpro gasket dry and it was fine, just put a little bit of gear oil on it to help to seal
2) How many qts of gear oil do i need?
2 quarts
3) what weight is recommended? my car is not a DD see maybe 2,000 miles a year
75W90
4) What brand? I have seen Valvoline and maybe Mobil 1
Mobil1 is fine but the Royal Purple I picked up from Kragen had the friction modifier already in it...with a torsen style differential that you have the friction modifier is not required but recommended
5) Syn fluid or regular fluid?
use synthetic fluid, it states it in the owners manual, regular fluid is required for the auburn (or eaton) units (which you don't have unless it isnt stock)
6) for my 2002 Trans Am do i need the friction modifier? How do you know if you do not need it
See above
7) Do i need to re torque the bolts or just nice and snug.
I just tighten them snug, you dont want to overdo it. I believe the spec is like 10-15ft-lbs, so I just estimated it, hasn't leaked since I did it a year ago

TORCHD 02 TA

iTrader: (39)

i know being that i have a 2002 Trans Am with the Torsen rear. Is that a limited slip diff? or a standard diff?

accordign to the manual

Standard Diff: 75W-90 Synthetic

LSD Diff: 75W-90 Synthetic with 4oz with additive

vjo90rs8

iTrader: (9)

Torsen=limited slip differential, the additive is not required with the Torsen differential but it is recommended to reduce noise (I believe GM issued a service bulletin for this) but definitely use synthetic.

TORCHD 02 TA

iTrader: (39)

Again this was taken from my manual...

Rear Axle (Standard Differential)SAE 75W-90 Synthetic Axle Lubricant

Rear Axle (Limited-Slip Differential)SAE 75W-90 Synthetic Axle Lubricant. Add 4oz Limited-Slip Axle Lubricant Additive

And this is th GM TSB:

GM issued a technical bulletin adding modifier to the rear axle oil. This was done to quiet what we call a "Rusty Screw" noise that we heard in a very small percentage of vehicles. This does not happen in all cases, however to address owner's concerns we asked that the modifier be used in all instances to insure that the driver would not get this noise. When replacing the fluid it is at the owner's discretion whether or not to add the modifier. Elimination of the modifier does not affect durability of the differential.

vjo90rs8

iTrader: (9)

Yeah, I understand, I'm just saying that if you don't have the "rusty noise" issue then the friction modifier is not required but it is recommended. They probably updated the manuals some year to add the friction modifier to avoid the hassle of getting future complaints. I ran Mobil 1 without the additive in my 90 camaro with a take-off torsen differential and had no problem, and ran it on my current 02 Z28 with no problem but during my last gear oil change I used it (Royal Purple).

TORCHD 02 TA

iTrader: (39)

I have never changed my gear oil since i owned the car. I bought it in 2005 with 17K on it. It is now 2009 and i have 47K on it.

I have no idea if LSD additive was added in or not....

vjo90rs8

iTrader: (9)

odds are it has never been changed. Just go to you local auto parts store, get some 75W90 synthetic fluid (Mobil 1, Royal Purple) and pick up some GM limited slip additive (only a few bucks, might as well add it, definitely a job you only want to one once, might only be able to get it at the dealer, not sure). I used a Felpro gasket because the first time I changed the fluid I used RTV sealant to make the gasket but I didn't wait long enough for it to dry, so when I put the cover back on and added fluid it leaked, so I redid it with the gasket, and not a drop since.

TORCHD 02 TA

iTrader: (39)

That is exactly what i was going to do..

Get 2 qts of either M1 or Valvoline Syn. either 75W90 or 75W140 or 80w90, get the GM LSD additive, Felpro gasket with black RTV sealant....

TORCHD 02 TA

iTrader: (39)

Today i bought the following....

2 qts Valvoline no syn 80w90
1 LSD additive
1 Felpro Gasket
1 thing of black RTV sealant

how long do i need to let the RTV set up before i pour the gear oil in?

vjo90rs8

iTrader: (9)

You should use synthetic, if you didn't see it try another place, it is required! Not saying that something will go wrong but why risk it. Also, if you use a gasket you don't need any RTV, it is either one or the other.

TORCHD 02 TA

iTrader: (39)

I keep gettign mixed results.

https://ls1tech.com/forums/6945359-post8.html
https://ls1tech.com/forums/7011990-post4.html
https://ls1tech.com/forums/10136818-post2.html

vjo90rs8

iTrader: (9)

Well, the first link is referring to the auburn differential (which requires a bit more friction than a torsen differential to work properly) which you don't have but I guess others have used the valvoline stuff with torsens. I'm sure you won't have any problems. I just like using synthetic in a location that recommends it, less friction, longer life, less parasitic losses, and it is a location that you will only change out about every 20K miles.

TORCHD 02 TA

iTrader: (39)

My car is not my DD, so it wont see any harsh conditions. So i dunno i think i should be fine...

Like i said i have no idea what is even in there now

TORCHD 02 TA

iTrader: (39)

see here are some other answers about syn. I give up.

https://ls1tech.com/forums/7878344-post4.html
https://ls1tech.com/forums/7903746-post2.html
https://ls1tech.com/forums/7024808-post9.html

vjo90rs8

iTrader: (9)

Yeah, im sure it doesn't matter but my point is, the manual says to use it, so why not. And you have a Torsen differential, just like my 02 Z28. IMO the engine and differential are great places for synthetic oil, the automatic transmission is not.

airforcemanss

iTrader: (23)

i don't want to hijack. but its a quick question related to topic. when are you suppose to change your rearend fluid every what???