"I have a UK 1986 Morgan Plus 8 with Fuel Injection and a LT77 gearbox, I have been told that the Castrol TQF oil originally specified for this car was the best on offer at the time, however with the latest oils available I would be better using Mobil 1 or EP75. What is your opinion and are there any disadvantages.
Regards, Stephen Clark


Chris Crane

Dear Lorne

First Rover recommended EP80 and was too thick so caused very notchy gear changes, especially when
cold.  Then they recommended Castrol TQF, a thinner automatic transmission oil but it had lousy lubricant properties. Lastly they recommended Castrol SMX, still an auto-tran fluid for a manual gearbox, but synthetic and supposedly better.

Most LT77's have problems whatever oil you use and they get no better with a rebuild. We all need to upgrade to the R380. By comparison, it is superb and not (at least) 17- 27 years old already

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Kindest regards,

Rpi Engineering

Bill Fink

The only oil we have ever used for the 5 speed gearboxes is automatic transmission fluid, type "F", which is used on the early Fords and readily available.
Bill Fink
Isis Imports Ltd.

To my recollection the gearbox is standard Ford, the gearshift linkage conversion is "Wooler," treat it like any other gearbox.

Bill Fink
Isis Imports Ltd.

John Sheally II


This fluid/lubrication goes on forever in every application. I am of the opinion that is it isn't broken do not fix it. If you have had no problems with your LT77 box with the required and recommended Castrol TQF  then leave it alone.

Ask others that have used other fluids and then make a decision of your own to stay with the factory recommended or change if you find better resulting "tried and proven results".

Technical advances have to be weighed against marketing of new products. The proven is just that, manufacturers put a lot of research into what they recommend and will usually update those recommendations if a better product enters the market.

Sincerely, John H. Sheally II

Rob Wells

We use EP 75/80 as the original TQF is a bit thin and not really suitable for gears that slide against each other and have higher momentary point loads than they do in auto boxes. This has been confirmed by our man who worked for many years in the Rover transmissions department!
Happy New Year to all.

Rob Wells