What you need for a rear differential fluid change - Page 3

Chris05STi · 04-07-2006, 10:35 PM

Was just on the website...which one is the BEST for the gearbox and rear diff? So many to choose from....

Arcticsun · 04-08-2006, 05:06 AM

stick with valvoline dino 75w-90 to avoid problems with synthetic, and motul 90pa for the rear diff

91TB78 · 04-08-2006, 07:10 AM

I'm doing this in about 10 mins. I bought the LSD fluid from subaruparts.com for the rear diff and then bought Valvoline 75W-90 for the front/tranny.

Do you think it's a must to get a fluid pump to remove the remaining fluid?

Rev · 04-08-2006, 07:20 AM

You'll need the pump to put the fluid in, at least it seemed hard to me to find a proper angle to tip in the bottle into the hole... no space in there...

91TB78 · 04-08-2006, 07:41 AM

so the pump is used to remove the remaining fluid left in the diff and tranny AND to fill it back up?

Rev · 04-08-2006, 07:46 AM

For the tranny I just removed both drain bolts, and jacked the car from the rear to push the fluid forward, I ended up filling 4.3 quarts, so that was enough. No pump needed for draining at least.

The pump is certainly needed for filling the rear diff, though.

A long necked funnel helps to fill the tranny, unless you're taking the IC out.

This time I'm taking the pan off and resealing (when I hit 40k miles, though)

StiManny · 04-10-2006, 12:59 PM

i used redline 75w90 gnl 1qt with friction modifiers and the trans used 4.50 qt of 75w90 without friction modiers.cleaner shifts.....i would change it every 12 k i changed mine at 18k and it was dark.......

91TB78 · 04-10-2006, 01:55 PM

I did the change for the tranny and rear diff this past Sat. The tranny was a breeze, but filling the diff was a messy pain. The pump I bought wasn't all that great. For those that have had good results, what type of pump are you using?

BHazel · 04-12-2006, 06:29 PM

Quote:

Originally Posted by EricK

You must use one of the three fluids listed above for the rear LSD diff.You need to use Subaru 90 wt. LSD oil or Motul 90PA LSD oil or Silkolene BOA90 LS.If you dont your rear diff. will lock up at strange times or be noisy.

I thought I had heard people using the Amsoil in the diffs with no issues. Why would this not work?

BHazel · 04-12-2006, 06:31 PM

Quote:

Originally Posted by Arcticsun

stick with valvoline dino 75w-90 to avoid problems with synthetic, and motul 90pa for the rear diff

What issues with synthetic?

solbergfan · 04-13-2006, 07:47 AM

Quote:

Originally Posted by BHazel

I thought I had heard people using the Amsoil in the diffs with no issues. Why would this not work?

Amsoil does not make a mechanical LSD specific oil.

BHazel · 04-13-2006, 03:07 PM

Quote:

Originally Posted by solbergfan

Amsoil does not make a mechanical LSD specific oil.

This is the Amsoil Severe Gear oil.

https://www.amsoil.com/storefront/svg.aspx

It states limited slip compatable.

Big Cam · 04-14-2006, 03:35 AM

do all STI's come with the magnetic drain plug or was it an option?

solbergfan · 04-14-2006, 04:07 AM

Quote:

Originally Posted by BHazel

This is the Amsoil Severe Gear oil.

https://www.amsoil.com/storefront/svg.aspx

It states limited slip compatable.

It is compatible with hypoid or helical gear type LSD's like the one found in the standard WRX. The STi has a mechanical (clutch type) LSD therefore it requires the mechanical LSD oil. Amsoil does not make anything compatible with a mechanical LSD, neither does Redline or Royal Purple.

BHazel · 04-14-2006, 03:15 PM

Quote:

Originally Posted by solbergfan

It is compatible with hypoid or helical gear type LSD's like the one found in the standard WRX. The STi has a mechanical (clutch type) LSD therefore it requires the mechanical LSD oil. Amsoil does not make anything compatible with a mechanical LSD, neither does Redline or Royal Purple.

Here is what I sent to Amsoil Tech Support:
I have heard some conflict about the application of the SVG gear oil. I have a 2005 Subaru Impreza WRX STI and was wondering if the SVG oil could be used in the limited slip rear differential. I plan on putting it in the front differential and the transmission. Also, is the SVG gear oil compatable with brass syncros? Thank you,

From Amsoil:

"Thank you for contacting AMSOIL with your concerns.

In response to your inquiry, the SVG is recommended for the transmission, front and rear differential. It is safe for the synchros.

Thank you again for the opportunity to respond to your concerns. As always, please feel free to contact us again if we can be of further assistance.

Darryn Wallace
Technical Service Department
AMSOIL, Inc."

I will email them again with specifics on the rear diff. I just got a case of the SVG oil and intend on finding out if I can use it.

04-07-2006, 10:35 PM	#31
Chris05STi I Has a Turbo Timer Car: 2005 Subaru WRX STi Fav Mod: Every single one! Location: NJ Posts: 9,381 Join Date: Jun 2005 Trader Rating: (24)	Was just on the website...which one is the BEST for the gearbox and rear diff? So many to choose from.... This ad is not endorsed by this member. Please register or login to hide this ad.

04-08-2006, 05:06 AM	#32
Arcticsun Junior STI Driver Car: 08 Aspen STi Location: Detroit, MI Posts: 114 Join Date: Jan 2006 Trader Rating: (0)	stick with valvoline dino 75w-90 to avoid problems with synthetic, and motul 90pa for the rear diff

04-08-2006, 07:10 AM	#33
91TB78 S204 Racer Car: 06 IX MR Location: Minneapolis, MN Posts: 3,667 Join Date: Mar 2002 Trader Rating: (12)	I'm doing this in about 10 mins. I bought the LSD fluid from subaruparts.com for the rear diff and then bought Valvoline 75W-90 for the front/tranny. Do you think it's a must to get a fluid pump to remove the remaining fluid?

04-08-2006, 07:20 AM	#34
Rev STI Guru Car: 06 V70R Location: Hoffman Estates, IL Posts: 5,544 Join Date: Dec 2003 Trader Rating: (0)	You'll need the pump to put the fluid in, at least it seemed hard to me to find a proper angle to tip in the bottle into the hole... no space in there...

04-08-2006, 07:41 AM	#35
91TB78 S204 Racer Car: 06 IX MR Location: Minneapolis, MN Posts: 3,667 Join Date: Mar 2002 Trader Rating: (12)	so the pump is used to remove the remaining fluid left in the diff and tranny AND to fill it back up?

04-08-2006, 07:46 AM	#36
Rev STI Guru Car: 06 V70R Location: Hoffman Estates, IL Posts: 5,544 Join Date: Dec 2003 Trader Rating: (0)	For the tranny I just removed both drain bolts, and jacked the car from the rear to push the fluid forward, I ended up filling 4.3 quarts, so that was enough. No pump needed for draining at least. The pump is certainly needed for filling the rear diff, though. A long necked funnel helps to fill the tranny, unless you're taking the IC out. This time I'm taking the pan off and resealing (when I hit 40k miles, though)

04-10-2006, 12:59 PM	#37
StiManny Junior STI Driver Car: 2006 Subaru Wrx STi Fav Mod: HKS CERAMIC COATED HEADERS Location: Long Beach Posts: 181 Join Date: Mar 2006 Trader Rating: (0)	i used redline 75w90 gnl 1qt with friction modifiers and the trans used 4.50 qt of 75w90 without friction modiers.cleaner shifts.....i would change it every 12 k i changed mine at 18k and it was dark.......

04-10-2006, 01:55 PM	#38
91TB78 S204 Racer Car: 06 IX MR Location: Minneapolis, MN Posts: 3,667 Join Date: Mar 2002 Trader Rating: (12)	I did the change for the tranny and rear diff this past Sat. The tranny was a breeze, but filling the diff was a messy pain. The pump I bought wasn't all that great. For those that have had good results, what type of pump are you using?

04-14-2006, 03:35 AM	#43
Big Cam Senior STI Driver Car: 02 RSX Type S Fav Mod: 4300 H.I.D. Kit Location: Fargo, ND Posts: 380 Join Date: Mar 2006 Trader Rating: (0)	do all STI's come with the magnetic drain plug or was it an option?