10-40 engine oil used as gear oil!

1. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

   #1 26th November 2011, 17:53

   a few weeks ago a mate mentioned this as it was suggested by a local rally team. the idea being a much thinner oil releasing more power at the wheels.....
   
   apart from not being the recomended grade i can see it being prone to leaking as its much more thin.
   
   feel free to debate...
2. user_51379 Saxperience Forum Bum Joined: Mar 2011 plymouth Posts: 2921 mk2 VTS

   #2 26th November 2011, 17:55

   i thought thicker oil was needed because when the gbox gets hot the oil thins out
   correct me if im wrong
3. user_4681 Saxperience Post Whore Joined: Dec 2004 Grimsby United Kingdom (England) Posts: 5489 SUPERCHARGED saxo vts

   #3 26th November 2011, 17:56

   id like to hear oilman on this, can someone give him a nudge?
4. Bedford126 Saxperience Post Whore Joined: Jul 2010 Morley, Leeds Posts: 8469 Civic ep3 type r powered by TDI NORTH

   #4 26th November 2011, 18:29

   I know that on Subaru and Mitsubishi evo gearboxes it lets them run better because they have fibre washers inside and the thinner oil gets engorged in the fibre making them less prone to wear from friction. I have never heard of it being used in any other gearbox though. But in the evo's and wrx's the oil needs to be changed more often than the standard grade oil.
5. saxovtrmk1 Regular Poster Joined: Jun 2011 Wakefield Posts: 395 saxo vtr/vts 106 diesel

   #5 26th November 2011, 18:34

   i use 10w40 semi oil in all my gearboxs steven brears at leeds gearbox place told me to said its the best for it dont no how true but hs been re building gearboxs for years and i have had no issues
6. toger13 L-plater Joined: Mar 2007 Wakefield Posts: 54 Saxo VTS Turbo

   #6 26th November 2011, 18:35

   its quite common to run shit engine oil in boxes alot of gearbox places I know use 20w50 mineral oil in manual boxes
   
   Si
7. user_39821 Saxperience Forum Bum Joined: Dec 2009 Uckfield, East Sussex Posts: 3362 Citroen saxo 1.4 furio

   #7 26th November 2011, 19:11

   The main downside of doing so especially in fwd cars due to the diff being in there is that the pressure the oil will be put under buy a hypoid bevel gear is massive. the oil will begin to shear and cavitate
8. john-paul Frequent Poster Joined: Jan 2010 hetton/sunderland Posts: 662 250 BHP jp4 vts

   #8 26th November 2011, 19:35

   I ran half gear oil and half 10/40 and its the longest a gear box has ever lasted me
9. user_39821 Saxperience Forum Bum Joined: Dec 2009 Uckfield, East Sussex Posts: 3362 Citroen saxo 1.4 furio

   #9 26th November 2011, 19:49

   I'm still suspicious. after the millions invested in research and development of gear oils, i'm not sure why engine oils would be any better

   2 users thanked this post: raunchz, blackie_2k5
10. user_47680 Infrequent Poster Joined: Oct 2010 Cornwall Posts: 236 2001 Saxo VTR

    #10 26th November 2011, 20:01

    Quite interesting. You guys seen the wiki article?
    
    http://en.wikipedia.org/wiki/Gear_oil
    
    I'd like to hear what oilman says too. I can imagine its got to do with the life of the box, something like reducing the lost power but increases wear. Don't see why this would be that bad as long as you change the oil more often.
11. user_45322 Regular Poster Joined: Jun 2010 West Yorkshire Posts: 396 Saxo VTR. 1.4 Cinquecento.

    #11 26th November 2011, 20:57

    I have 10w/40 in my gearbox, never had any problems, no leaks and no failures.
12. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #12 26th November 2011, 21:11

    I can't see how engine oil is a suitable replacement for gear oil. For a start, there is no pumps in a gearbox, the viscosity of gear oil allows it to 'cling' to the inner workings and therefore transfer itself around the system. Once an engine oil gets warm it's going to be like water in comparison to a gear oil. Can't see a gearbox lasting especially when we're dealing with MA boxes that made of cheese anyway.
13. Barry123 Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS

    #13 26th November 2011, 21:12

    ... or I could've just read wiki and saved myself several strokes of the keyboard
14. user_36198 Saxperience Post Whore Joined: Aug 2009 ilkeston derbyshire Posts: 9823 C2 VTR stripped, 406hdi, clio 172

    #14 26th November 2011, 22:05

    plenty of gearboxes have oil pumps, LT85 and LT77, R380 land rover boxes all have them, 85 used to run on 20/50 engine oil latter 2 ran on atf until that was supersceded by mtf94