EP90 GL4 Diff Oil - or the lack of it on the market.

[Titanium7]

The only straight EP90 GL4 now on the open market appears to be the Castrol Classic mineral EP90 from Opie or Demon Tweeks.

Everywhere else just seems to have multigrade EP80W-90 or similar.

Would the more modern multigrade be OK as opposed to to the single grade for the Ford differential (with LSD) ?

[Jonathan Kay]

Which type of LSD?

Jonathan

PS: There's a vast amount of discussion on this in the archives. 

[Titanium7]

As far as I can work out the LSD is not the main factor in reference to the oil, the manual just says EP90 but it's getting like hen's teeth these days. Also GL4 is required. The LSD question seems only to matter in regards to the friction modifier, I believe but may be wrong but I think it may be an ZF LSD (2002 R500)

 

[DJ.]

Phil at Road and Race told me to use EP90 GL5 oil not GL4. I use Fuchs Titan Race 90 LS with my lsd

[Pendennis]

If you got the ZF you should be using GL5 mineral oil. I been using Comma LS80W-90 GL5 oil successfully but Halfords also do the GL5 same stuff

[cb4798]

Caterham sent me EP80W-90 as part of my first fill package for use on the BMW LSD.
 

[Titanium7]

Thanks everyone, have decided after some reading to go with  CASTROL AXLE Z LS 90 DIFFERENTIAL/DIFF/LSD OIL - REPLACES HYPOY LS 90 as its recommended by ZF. Now have to read more to see if it also needs the friction modifier as well. 

[7 wonders of the world]

Castrol LS (Limitied Slip) oils are specific for LSD's and will not require addition friction modifier additives.

[Titanium7]

Yes I spotted that with further reading. Thanks

[Paul Deslandes]

Just don't use GL5 oil in a Type 9 gearbox or you'll destroy the brass syncro rings.

[Nigel Riches]

Hi Paul, 

I don't know where you got the info about not using GL5 oil in a Type 9 'box, and knackering the synchros, but I have used Castrol Syntrax 75w/90 (meets or exceeds? GL5) in my BGH box for ages.

Not all synchros are equal, there are several different types of brass, (http://www.engineersedge.com/brass.htm)(http://drivelinenews.com/transmission-insight/dedicated-manual-transmission-fluid-can-significantly-reduce-running-costs/) some cost cutting, under speccing of material could give sub standard service components, which I have heard of from other people on these forums. 

Just now I am using Redline Lightweight Shock Proof in my Quaife 5 speed type 9, and the change action is crepe, so will be looking at changing to something more old school (can't get the Quaife recommended oil here) this gearbox oil business is a bit of a black art, which can be costly. 

Did you slog out some synchros by using GL5 oil? 

Regards, Nigel. 

[elie boone]

If your gearbox gets stiff in gear change action and u run GL5 and are not low on oil level, change to GL4 mineral and normally all will be ok. They sell now semi synthetic GL 3,4,5 witch they claim to be fine but as long as i can find mineral GL4 that is what i will use. 20 years ago i did use ATF in a type 9 for racing as it would have superior caracteristics when cold and i never had a problem trashing the box. With GL5 i did have a box that whent stiff in action when hot.

[Paul Deslandes]

Hi Nigel

if you Google the subject you'll find innumerable threads and postings around the various car marque sites where the armchair experts are split between GL5 being ok in gearboxes with brass components, or not.  My info came from the US Ferrarichat site from when I had a 1976 308 and it was strongly advised against.  Now, it may be that the warning relates to older design/metallurgy gearboxes and that newer designs aren't affected.  I'm not sure which camp the Type 9 sits but it must be a pretty old design by now and I suspect that some of the replacement parts are now of dubious eastern origin and metallurgy!

Interestingly, a lot of us use Redline MTL which, as I understand it, BGH don't recommend as they say it causes wear.  I've used nothing else for at least 10 years with no ill effects.

I guess you pays your money and takes your choice.  It would be interesting to hear Ford's recommendations.

HNY

Paul

[DJ.]

From the Haynes Sierra V6 manual:

Manual gearbox early models: Gear oil SAE 80EP Ford spec SQM 2C 9008-A

Manual gearbox late models: Semi-synthetic gear oil 75W/90S Ford spec ESD-M2C-175-A

Final drive: Hypoid gear oil SAE 90, API GL5

[7 wonders of the world]

GL4 for the gearbox as GL5 is in simple terms too slippery and does not allow the baulk rings to bite thro and equalise the shft speeds quickly resulting in a slow shift - which usually means the driver applies more force to speed the shift which cravke the nylon gearlever clip, braeks the baulk rings, mashers the blocker bars, burrs the teeth on the gear or a combination of all the above.

Standard wide ratio 5 speeders that are raced or driven with vigour suffer the worst failures as the aobcve problems are exentuated by the wide ratios and increased difference in shaft speeds

you need a degree of friction for a syncomesh set up to work hence GL4 is the correct oil, many late cars including BMW and Honda have had this problem with GL5 too.

As previously mentioned Redline MTL offers a supeior shift in both 5 and 6 speeders