Gearbox oil

[Malc]

Can anyone who has overdrive fitted please tell me what oil they are using in it and, ideally, how many miles they have covered?

There seems to be a lot of conflicting information out there, oil manufacturers such as Millers will tell you that their EP90 GL4 spec' product is correct but Laycock documentation says to use 20-50 and to avoid EP. I'd rather base my decision on real world experience if it's available.

Thanks

Malc

[Martec]

Hi, You don't say what year your car is or what type gearbox you have fitted?

The early cars had the horrible Moss box which used engine oil 20-50. I started with this box but it was so worn I fitted the later fully synchromesh but with an overdrive a very nice box to use and this I have run on EP90 for the last 10 years.

Both the diff and gearbox oils are changed every 4 years and are ready for it, the oil goes in straw coloured and comes out black.

Brian

[PPV]

Hi, my 3.8 with overdrive has the Moss box and besides being a bit 'butch' works fine and is a positive experience (touch wood). My service manual recommends a 20w/30 or straight 30 oil. Total capacity is 4 imp pints for gearbox and overdrive.
It says for the later all sync gearbox use EP 90 and this should be from chassis no 234125 for the 3.8, 169341 for the 3.4 and 119200 for the 2.4, all R.H drive models.
Not sure about changing frequency as it says every 10,00 miles with no time suggested. I ran mine for 10 years and it was almost as clean coming out as when put in, but it had only done about 6,000 miles.
Regards,

[Malc]

Thanks for the replies - actually my gearbox is from a 1968 420 with Laycock overdrive but I have just fitted it into my E-Type Series 1 4.2 2+2. From the various correspondence I have seen, the ideal solution seems to be EP90 in the box and 20-50 in the overdrive!

There just doesn't seem to be any consistency in the advice - Millers says their GL4 80w90 extreme pressure transmission oil is 'recommended for vehicles with overdrive', yet the Laycock manual says avoid EP90 and use 20-50. Have the spec of the oils changed since the Laycock manual was produced?

Malc

[Martec]

The gearbox and overdrive are one system, fill one it fills both (or atleast my fully synchro and overdrive box is).

You are luck to have a good moss box mine at 97,000 miles only had synchro on 4th gear, hence horrible to use.

I've emailed a number of oil companies Millers, Esso, Mobil, Comma and others about the MkII and the 'new' S type, some can't be bothered to reply, others have the incorrect records (only covering the popular models. For many years in the past I got no response for MkII but a reply if I said E type, One snotty yuf in Halfords proceeded to tell me there was no such thing as a MkII model, it had to be 'something' MkII (ie escort MkII, his example). Pointing to the car parked outside didn't shake his all encompassing knowledge.

So not surprised at your replies, You can contact the club experts for the definitive answer, I've always had a good response from Ken Jenkins for both the MkII and the S type.

Best wishes
Brian

[Malc]

Hi thanks for your replies - I appreciate that the box and overdrive are 'one' but it seems ironic that if you have a standard box (mine is not a Moss box by the way) then the recommendation is for EP90, but Laycock say that you should use 20-50 (mine has the Compact Type A overdrive). If you read the information from Millers on their 'Classic Gear Oil 80w 90-GL4', it indicates that it is an 'extreme pressure transmission oil to GL4 for classic transmissions from 1950s onwards. Recommended for vehicles fitted with overdrive'. However I have also looked in the Laycock technical manual which states that 'under no circumstances should extreme pressure gear oils be used, because the centrifugal effect of the planets may separate some of the additive from the oil and cause sludging'.

Where do you go from here? Have the specification of oils changed since the advice from Laycock was published?

Malc

[piman]

Hello Malc,

this is a question in which both engine oil and gear oil is used by different manufacturers for basically the same application. My Triumph with a manual 'A' type overdrive, like the Jaguar's, specifies 90 gear oil. Other (MG possibly?) specify engine oil. In practice both work well so take your choice, I follow the workshop manual in my choice.
I understand that viscosities of engine and gear oil are not directly comparable as different parameters and testing methods are applied? If using gear oil do stick to GL4 type (Not GL5)

Alec

[oldtimer]

Hi All, Talk about confusing.
Being an 'ole geezer knowledge is like lino it rolls up behind you. (Linoleam, an old fashioned floor covering,- ask your granny -that's for the benefit of the young ones)
Where was I - Oh Yes, listen to Uncle Martec he has got it in one, use EP90.

I believe the confusion comes in the early and late type Laycock Overdrive.
The early unit has a vertical solenoid and the later compact version has a horizontal solenoid sticking out the back.

The later o/drive version was fitted to a new G/box with baulk rings (synchro) on ALL FOUR forward gears. This G/box contained an oil pump at 5psi when used without an o/drive. When fitted with an O/drive the G/box is pressure fed from the O/drive pump

Information extracted from Jaguar Workshop Manual - Supplementary Information.
Also -Oil change every 12,000 miles

That's yer lot folks , past my bedtime

Oldtimer
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