Wednesday, 29 October 2008

Which Diff Oil

About to fill my Marlin van axle with oil - anyone have any recommendations as to which is the best for the job ?

Thanks

16 comments:

  1. Having tried most types of oil, the best I have found so far is Millers fully synthetic CRX 80w140 Heavy duty Gear Oil. Its expensive but it works. The MG uses the same crown wheel and pinion set up as the Marlin/MGB but uses a four star diff running on steel to steel plain bearings. Dudley  

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  2. Millers CRX LS 80w140 BM, heavy duty gear oil with shock
    protection for LSD, datasheet 1208/1 works for me.
     
    I bought it a year or two  ago from Jeff Smith
    Classic Lubricants, York, 01430828453, I think it cost about £11 a
    litre.
     
    TTFN
    John Rhodes

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  3. John Oh. Why the shock protection? Are we running a lim slip, surely not? Dudley

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  4. I should clarify. There are two versions of Millers CRX 80w140. The version I have been using and the LS version with addatives for use with lim slip difs. I dont know but I doubt if there is any advatage in using the LS version in a none lim slip diff. Dudley

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  5. I use Redline transmission oil..the Heavy Duty Redline stuff......available from Demon tweeks, and maybe elsewhere.....in my skud transaxle.   said to withstand heavy shock loadings...its also very red!   Despite having a home-built final drive with seat-of-the-pants CWP setting-up...ie I guessed, not too tight, not too much play....[my engineers bloo actually rubbed off before I could see much, so I gave up...I think it was all the rain!]....so far no whining, despite an awful lot of road useage [skud is currently my only road car]....   I was advised to use Redline, I think, by Simon Woodall, bless his wooly socks!

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  6. Seconded for the Redline stuff - used in the Yeller Dutton also with a guessed CWP setup (by me) - so far no metal bits falling out, no whining, and seems to work rather well.    However - we don't tend to spend a couple of hours digging a hill up, smoking the tyres and holding a trial up for following competitors when one wheel starts to spin and forward progress slows to glacial rates, so we don't abuse the diff quite as much as some do.   John is using the Millers stuff in a sporting trials car - I could go into the highly technical tribology reasons for using an LS oil in a common or garden free diff and why I persuaded him to buy it, but you'd get bored.   Of course, if you beg nicely, I'll find the time to explain.   Bri    

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  7. No, the Yeller Dutton doesn't have an LSD, although our
    wonderful performance must sometimes give that impression, it was just
    what was on the stall at the time. (Shyness and self deprication have never been
    a problem for me). 
     
    Is it my imagination or did I hear of oil that goes solid
    when an electric current is passed through it? It may have been something I saw
    years ago on Tomorrows World, on TV. A few oils seals extra here and there
    to keep the half shafts freely rotating whilst the current is on and we may
    yet see the scrutineers looking for wires going to the back axle.
    Weeee.  

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  8. Dudley when we were both at Race Retro the other year I went and had a chat with the tech guys from Millers (or was it Redline?).  Anyway they advised the LS shockproof oil for a vw transmission...which was pretty much the opposite of what their blurb says.  I was quite surprised because presumably whilst it would be good for the diff it might not be so good for my syncromesh gears...?

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  9. Just to throw in another option! My Troll has a Ford English axle with a Fack diff and a low C.W.P supplied by Lotus Cortina spares in Somerset. Lotus Cortina spares were adament that I should use Castrol Product B373 oil. This is an oil specifically for limited slip differentials but they say its excellent for non LSD units. One thing that I do do is change the diff oil regularly by using a pump to suck it out. It always surprises me how dirty the old oil can get after just a few trials. Castrol Product B373 is available from Castrol Classic Oils. The only problem is if you get a drop on you it really smells for ages! Stuart Harrold

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  11.   Many years ago (the early Seventies to be more precise) when I started trialling the Dellow, I rang Castrol's technical wallah at Swindon and asked for advice on diff oil.   Having explained the scenario of prolonged wheelspin and the known problem of planet gears seizing on their pins,  his answer was :- "We have one gear oil into which we chuck all the best additives known to man. It is our competition grade LSD oil, Product B373. It is perfectly OK for non-LSD axles by the way." I used it from then on in the Dellow and never had a single diff failure. Also used it in the Allard and will be using it in the HRG.   Not too sure about the need for "shock protection" as such ? There IS a need for retaining lubricant on the planet gear bearings and pins under prolonged wheelspin. When these run 'dry', the surface friction causes seizure and then you strip the teeth off, diff jams up and quite often bits end up between the CW&P ruining that as well. The NTF boys used to turn down the pins, build them up with braze and machine back to size. Theory was that the new bearing material was less likely to "pick-up" and seize in the steel pinion. They also went to the trouble of spark-eroding extra lubrication holes between the gear teeth. Needle rollers are probably a better way to go if your pocket is deep enough.

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  12. I need to replace the diff oil in my 205, but as the gearbox oil is shared to the diff I need to choose something that will be compatible with the gearbox. I spoke to someone at the start of the Exmoor Clouds and they said they had used the Redline oil in a 205 but as its so thick when the engine was cold you couldn't put it into gear, so they had to leave it in 1st gear the night before.

    Can anyone confirm that the oils discussed will be ok for my gearbox ?

    Thanks

    James

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  13. After chatting to Dave yesterday I'm going to use the Redline stuff.

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  15. Hi James, Which Redline did you use, did it work ok, and did it make a blind bit of difrence?!! Cheers Jason

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  16. Hi Jason,

    Redline Heavy ShockProof Gear Oil. I haven't actually put in in yet, still running the regular oil. I don't know if i will even be able to notice a difference other than it being really thick when its cold. But if it makes the diff last longer im happy!

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