New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

Gear oil

Old 06-16-19, 02:55 AM
  #1  
Junior Member
Thread Starter
 
Join Date: May 2019
Location: WI
Posts: 6
Received 0 Likes on 0 Posts
Gear oil

What oil to use for transmission, and diff? Diff is a limited slip, and has manual trans. What Weight? Best brand?
Slowspoke_fb85-insta is offline  
Old 06-16-19, 07:22 AM
  #2  
10AE Restoration Guy
iTrader: (91)
 
mazdaverx713b's Avatar
 
Join Date: Oct 2003
Location: Vermilion Ohio
Posts: 16,773
Received 139 Likes on 135 Posts
Given your username, are you asking for an 85 GSL? There is a lot of debate on this as people prefer different brands and will deviate from the factory specified weight. I have used Redline MT90 in my manual transmission on my FB's for years and have had great luck! I have been running Motul in my Porsche 944 and the stuff is also amazing.

For the rear differential, if you have a limited slip differential, you will need a friction modifier or buy a gear oil with a modifier already added in to the gear oil. Amsoil 80W90 has treated me well over the years. I have also used Royal Purple 80W90 in the rear diff on my 85GS and its been fine and has given me 0 issues! If I need to add a friction modifier, I use BG LSII.
mazdaverx713b is offline  
Old 06-16-19, 09:25 AM
  #3  
Junior Member
Thread Starter
 
Join Date: May 2019
Location: WI
Posts: 6
Received 0 Likes on 0 Posts
Im asking for a gs on what oil to use
Slowspoke_fb85-insta is offline  
Old 06-16-19, 11:36 AM
  #4  
Out In the Barn
iTrader: (8)
 
KansasCityREPU's Avatar
 
Join Date: Mar 2005
Location: Liberty, Missouri
Posts: 4,289
Received 106 Likes on 101 Posts
The answer can be found here for diff: http://www.foxed.ca/rx7manual/manual...rear_axles.pdf

12A - Standard rearend (non-LSD) 1.3 quarts
12A - LSD rearend 1.6 quarts
SAE80W for 0 degrees or lower
SAE90W for 0 degrees or higher

Brand is up to preference

For LSD ensure to include LSD additive. Ford make a good one.

Manual trans uses same oil. About 1.5 Quarts from the top of my head. Ensure to remove filler bolt first before removing drain plug on trans.

Last edited by KansasCityREPU; 06-16-19 at 11:41 AM.
KansasCityREPU is offline  
Old 06-16-19, 11:41 AM
  #5  
Rotary Madness
iTrader: (2)
 
rxtasy3's Avatar
 
Join Date: Jun 2002
Location: Spartanburg, SC
Posts: 7,537
Likes: 0
Received 64 Likes on 60 Posts
any 80/90 weight gear oil will suffice. with the drum brake rear u won't need the additive necessary if it were an lsd.
rxtasy3 is offline  
Old 06-16-19, 11:44 AM
  #6  
malignant narcissist
iTrader: (2)
 
diabolical1's Avatar
 
Join Date: Feb 2002
Location: FL
Posts: 9,525
Received 61 Likes on 57 Posts
Amsoil here. i've always heard good things about Redline transmission lubricants - since the 90s, and would like to try it someday, but so far i have only used their motor oils.

80W90 is good and as Mazdaverx713b said, you will need an additive for the LSD.
diabolical1 is offline  
Old 06-19-19, 06:08 AM
  #7  
Junior Member
 
Realr's Avatar
 
Join Date: Aug 2013
Location: Trinidad
Posts: 21
Likes: 0
Received 0 Likes on 0 Posts
Amsoil 80/90
Realr is offline  
Old 06-19-19, 02:58 PM
  #8  
Junior Member
 
Join Date: Nov 2016
Location: Fairfax Station, VA
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
Redline MT90 in the manual trans, Redline 75W90ns (NS has no lube additive) then I add 1-2oz of additive in the rear. I find the one with the additive in it have too much, and can make the rear slip. None at all will lead to binding in the rear (you'll hear it). You want enough to stop the binding but not make your rear end crazy loose. I race my 85 GSL, so maybe for regular driving the slippy rear won't be as noticeable. Dunno. I do know I change trans and rear fluids annually, and the rear smells horrible when I do... I don't know why it stinks so bad.
Shoal07 is offline  
Old 06-20-19, 11:55 PM
  #9  
Junior Member
 
Join Date: Jun 2019
Location: CA
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by mazdaverx713b View Post
Given your username, are you asking for an 85 GSL? There is a lot of debate on this as people prefer different brands and will deviate from the factory specified weight. I have used Redline MT90 in my manual transmission on my FB's for years and have had great luck! I have been running Motul in my Porsche 944 and the stuff is also amazing.

For the rear differential, if you have a limited slip differential, you will need a friction modifier or buy a gear oil with a modifier already added in to the gear oil. Amsoil 80W90 has treated me well over the years. I have also used Royal Purple 80W90 in the rear diff on my 85GS and its been fine and has given me 0 issues! If I need to add a friction modifier, I use BG LSII.
cosign on this. minus the royal purple. had a bad experience with that brand a while back and never used them since (im old)
marshun is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dragger
3rd Generation Specific (1993-2002)
8
06-19-19 02:56 PM
glemmers
Rotary Car Performance
1
07-12-02 01:43 PM
TainoIndian
3rd Generation Specific (1993-2002)
0
04-15-02 11:12 PM


Thread Tools
Search this Thread
Quick Reply: Gear oil


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: