Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Gear Oil...

  1. #1

    Gear Oil...

    Hello Guys,

    What grade gear oil should be used? Mine car is a '67S and will I need GL-4 oil or will GL-5 do fine. I've read that GL-5 contains 50% more sulphur and it tends to etch the synchros, causing them to wear prematurely....

    Also is there any good using a LSD oil in a non-LSD tranny? Some have told me that the LSD properties is good to help the synchros....

    So, GL-4 or GL-5? My VW calls for GL-4. How about the early 901 box?

    Thanks!

    Sprint.

  2. #2
    Goldmember ttweed's Avatar
    Join Date
    Oct 2002
    Location
    La Jolla, CA
    Posts
    1,429
    Sprint-
    There is a lot of debate about this and no real consensus about what is best. The difference is in the friction modifiers used in oils for LSD clutches. They are not recommended for non-LSD trannys, only for ZF LSD types, to keep the clutches from chattering. See this link at Paragon Products.
    I use Swepco in my non-LSD 901 and Mobil synthetic gear lube in my LSD-equipped 915 (which has a Torsen type LSD.)

    TT
    Tom Tweed
    Early S Registry #257
    R Gruppe #232
    Rennlist Founding Member #990416-1164
    PCA National DE Instructor
    Read my surf novel!

  3. #3
    Moderator Chuck Miller's Avatar
    Join Date
    Oct 2002
    Location
    Reseda, CA.
    Posts
    12,418
    This is how it worked out for me in my old 'crunchy' (soon to be rebuilt) 915/LDS gear box…

    Always put Swepco + LSD additive until about 2 years ago when I tried the highly recommended Torco synthetic.

    ..."put this stuff in your old tired boxes and they'll be like new"

    Again, this WAS an old tired box, and the synthetic was TERRIBLE ! … even with a LSD additive it was hard shifting plus ALLOT of diff. chatter.

    I immediately switched back to Swepco + the Kendall LDS additive and all was well again.

    An old Porsche mechanic said that with the 'old' 901 and 915 gear boxes the new synthetics were TOO slippery and the syncros needed a slight bit of resistance to work properly…

    ... go figure

    My two cents,
    Chuck Miller
    Creative Advisor/Message Board Moderator - Early 911S Registry #109
    R Gruppe #88

    TYP901 #62
    '73S cpe #1099 - Matched # 2.7/9.5 RS spec rebuild
    '67 Malibu 327 spt cpe - Period 350 Rebuild

    ’98 Chevy S-10 – Utility
    ’15 GTI – Commuter

  4. #4
    And..I've been running TORCO synthetic in my 915 with factory limited slip, and love it. Gordon ledbetter "freshened" my gearbox a few years ago...to as new. 75-140 TORCO, GL6 with limited slip additive. So, I'd say choice of gear oil may depend a lot on the condition of the gearbox? One plus here...it doesn't cost an arm & a leg, materials wise, to try various products until you find the one that works well for you.
    Paul D. Early S Registry #8 - Cyclops Minister of West Coast Affairs
    "Now, to put a water-cooled engine in the rear and to have the radiator in the front, that's not very intelligent." -Ferry Porsche (PANO, Oct. 1973)

  5. #5
    Originally posted by ttweed
    Sprint-
    There is a lot of debate about this and no real consensus about what is best. The difference is in the friction modifiers used in oils for LSD clutches. They are not recommended for non-LSD trannys to keep the clutches from chattering. See this link at Paragon Products.
    I use Swepco in my non-LSD 901 and Mobil synthetic gear lube in my LSD-equipped 915.

    TT
    Ok, the link says not to use FM in non-LSD cars, so that throws the theory my old mech (whom I've also thrown out the window) has that LSD oil is good for all trannies...

    He said something about his own 3.2 Carrera being 'locked' in 5th gear when he coasts to the lights and can't get it free (very difficult) till he put LSD oil inside and things got better... Makes any sense?

    My car is getting like that too... If I hold 4th gear for too long, it's hard to get into 5th. Not that I can't find the gear but it seems harder to slot it in?

    And after a long highway drive in 5th, I find some difficulty to go to neutral...

    Any thoughts?

    Thanks!

    Sprint.

  6. #6
    Originally posted by Chuck Miller
    This is how it worked out for me in my old 'crunchy' (soon to be rebuilt) 915/LDS gear box…

    Always put Swepco + LSD additive until about 2 years ago when I tried the highly recommended Torco synthetic.

    ..."put this stuff in your old tired boxes and they'll be like new"

    Again, this WAS an old tired box, and the synthetic was TERRIBLE ! … even with a LSD additive it was hard shifting plus ALLOT of diff. chatter.

    I immediately switched back to Swepco + the Kendall LDS additive and all was well again.

    An old Porsche mechanic said that with the 'old' 901 and 915 gear boxes the new synthetics were TOO slippery and the syncros needed a slight bit of resistance to work properly…

    ... go figure

    My two cents,
    I'm thinking of trying Royal Purple's tranny oil. Anyone tried it before?

    I'm in Singapore. Can't find any Swepco here...

    Sprint.

  7. #7
    Originally posted by pwd72s
    And..I've been running TORCO synthetic in my 915 with factory limited slip, and love it. Gordon ledbetter "freshened" my gearbox a few years ago...to as new. 75-140 TORCO, GL6 with limited slip additive. So, I'd say choice of gear oil may depend a lot on the condition of the gearbox? One plus here...it doesn't cost an arm & a leg, materials wise, to try various products until you find the one that works well for you.
    Sigh... Alas, I'm in Singapore. Too far away with too few good products.

    Sprint.

  8. #8
    Senior Member
    Join Date
    Feb 2003
    Location
    Corpus Christi, Texas
    Posts
    192
    A gear oil with friction modifier will work OK in a car without limited slip but it won't work as well as a gear oil without friction modifier. A transaxle design is unique in that the diff and gear box share the same oil. Normally a diffferential would want something very slippery and the synchro gear box would want something not too slippery for easy synchro engagement. Major shifting problems are likely an adjustment or synchro issue.
    Jason Burkett
    Paragon Products
    www.paragon-products.com
    Early 911S Registry #428
    R Gruppe #375
    1973 911S
    1972 911T
    1974 914 Limited Ed. Blk/Yellow
    1989 944 Turbo
    1993 968 Turbo RS
    1967 Shelby GT500
    1968 Shelby GT500 Conv.
    2010 VW GTI, Daily Driver

  9. #9
    Originally posted by Paragon
    A gear oil with friction modifier will work OK in a car without limited slip but it won't work as well as a gear oil without friction modifier. A transaxle design is unique in that the diff and gear box share the same oil. Normally a diffferential would want something very slippery and the synchro gear box would want something not too slippery for easy synchro engagement. Major shifting problems are likely an adjustment or synchro issue.
    Thanks Jason! Does it matter what kind of limited slip the tranny has? I think only the clutch type makes that clatter, right? So if we use a torque biasing one like GT or Quaiffe, we won't need LSD oil?

    Sprint.

  10. #10
    Sprint? I've heard nothing but good about royal purple products. I've never tried them personally. Perhaps you'd be willing to be our guinea pig?
    Paul D. Early S Registry #8 - Cyclops Minister of West Coast Affairs
    "Now, to put a water-cooled engine in the rear and to have the radiator in the front, that's not very intelligent." -Ferry Porsche (PANO, Oct. 1973)

Similar Threads

  1. WTB: B 1st gear and GA 2nd gear for 901 transmission.
    By RSwannabe in forum For Sale: 911 Parts
    Replies: 0
    Last Post: 01-20-2013, 10:25 PM
  2. 901“x” gear set
    By marankie in forum For Sale: 911 Parts
    Replies: 0
    Last Post: 01-31-2012, 05:42 AM
  3. WTB: I , O 901 gear
    By preS in forum For Sale: 911 Parts
    Replies: 15
    Last Post: 04-11-2011, 07:25 PM
  4. WTB 901 aa,, b, c first gear
    By Chris Pomares in forum For Sale: 911 Parts
    Replies: 0
    Last Post: 02-20-2011, 06:51 AM
  5. WTB gear sets for 911/01 gear box
    By 60surfer in forum For Sale: 911 Parts
    Replies: 1
    Last Post: 05-31-2009, 09:27 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.