Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Oil and additive for MT82 gearbox on 3.7 Roadster

Having gained access to the filler plug on my Roadsters gearbox I'm keen to improve the shift speed and smoothness. A custom short shift mounted entirely to gearbox would probably solve the issue but looking at an interim improvement.

Scouring the Mustang forums provides quite a few revelations on this joint project Getrag/Ford gearbox. There were many complaints when first produced including poor selection of certain gears when cold. These rose to such a level a class action was taken out against Ford. They did make some improvements which included changing the recommended oil spec. to a dual clutch type. A Motorcraft oil additive XL-18 was also made available to improve selection but it's expensive, not available over here and often OOS in the States. It's also been speculated that from 2015 onwards the additive was used in the first factory fill but none know for sure.

Given above I'm looking towards a full oil change. Redline would be my first choice but they don't offer a dual clutch oil as per current Ford spec., and when questioned are keen to point this out. Having said that many have used Redline MTL to good effect over several tens of thousands or miles. This full synthetic GL4 spec oil doesn't have a displayed viscosity but is in the range 70-75W/80 with many attributes including slicker changes, so I'm tempted to try.

Just wondered on others thoughts especially anyone who has performed oil change on this particular gearbox. The righteous of course insist on adhering strictly to Ford oil spec. but given their changed recommendations and need for additive others are willing to look at alternates.

Incidentally the filler plug is not a combined level plug. The correct fill converts to 2.5 litres so three US quart bottles would be needed to cover.

All I would add Richard is to measure what comes out. The Getrag in the Series 1 doesn't give up all the oil when drained, a significant amount appears to stay inside, unless the quoted fill volume is overstated of course.

Thanks Dave good point. There was some discussion on this on a LR forum as apparently a variant also uses the MT82. I think the figures were 2.3 wet fill and 2.6 litres dry fill.

I switched to MTL on my 3.0 but the results were not outstanding. Shifting was a little smoother at first, but I find now that while there is a noticeable benefit when the oil is cool, at running temperatures the same old clunkiness creeps back in. Changing down from 5 to 4 is worst, and engaging First is not exactly smooth. I wish I could find something that would speed up the box.

Richard didn't Cain fettle John the FM's treasurers box. oooh Matron. Perhaps Cain or John has advice.

Yes JR not often on here and forgot to ask when I last saw him. Guessing they got hold of the Motorcraft XL-18 additive although it's around $50 for 0.9 fl.oz dose!


There is a Redline MT90 which is advertised as 75W/90 so a tad thicker and would have probably worked better for you.

Richard, I would have chat to the tech lads at Millers oils, they do some very clever stuff the WRC teams use in gearboxes

Thank you. We will give it a try.

Thanks Jon. Have checked and Miller's offer a dual clutch transmission oil DCT DSG which conforms to the latest Ford spec WSS M2C200-D2 as do unsuprisingly Ford. These are ATF oils though and obviously thin with no published viscosity. Furthermore it's not clear if the scarce Motorcraft XL-18 additive is required as well.

I note in my handbook that MMC suggest their tied brand Morris Lodexol FS75W/90 and even quote quantity. Particularly amusing as they offer no ex factory access for gearbox re-fill

Reading further on the subject I'm still tending towards the Redline MTL which falls viscosity wise nicely between DCT auto fluid and commonly available synthetic 75W90 both of which Ford have recommended for the MT82 over the years. It seems a popular choice and will at least give me the chance to put clean fluid in as the smear I saw from filler plug is starting to look murky.

Let us know how you get on Richard