Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing 2010 Roadster diff noise

There are pictures of a diff oil change here

The refill plug requires an Allen (hex) key, but there is limited clearance between diff casing and fuel tank. Fortunately I had a correct size key with short shank one end which could be engaged with plug. A ring spanner over the longer shank gave enough purchase to undo.

BTW the drain plug hex will likely be covered in underseal which will need to be removed to allow easy fit to correct socket.

If any garage refuses to change diff oil on one of the simplest cars around I would be concerned what work they could undertake

Thanks, I checked everything I could from above with the tooltray out. Gave the avo's a tug and looked for the anything loose or out of place/alignment. Found nothing wrong.
Also, its a familiar noise that has been there on sharp turns since new as far as i remember. Just louder now.

👍👍

The refill plug on the later LS diffs is a hex socket, however on the earlier Roadsters it can be a large hex head cap, almost 1" AF, sometimes easier to access with an adjustable spanner so long as it's a decent quality one with parallel jaws

Step 1. Check you can remove and refit the filler plug BEFORE draining the old oil.
That way you know you can refill and not have an empty diff and then have the hassle of sorting out the refill.
SOD’S LAW........there’s always one bolt/screw that fails to come loose easily or snaps off.

Inaccessible fixings sometimes need “ special tools”. These might be spanners adjusted ( ground slimmer, bent to fit etc. Keep them in a special tools toolbox! Keep it a secret so you can lend them to someone who you know will return them.

Quick update,
Got the car home safely. just a little bit of a whine on the Gotthard pass, no chattering. Much cooler weather and rain might have helped keeping the temp of the diff lower. I drained the oil from the diff and it looked pretty 2nd hand almost black. I looked for castrol SAF XJ but that seems to be an older spec. no longer on sale here and not on the Castrol website. On the Castrol site they now have Transmax Axle Limited slip 75W140 for this purpose. I confirmed with the Morgan dealer/importer here that this is what they use. So I bought this but I am still not sure if I should add a friction modifier to this oil. On the filler of the diff there is a plate (as a washer with a tab) with the text; "use approved oil & friction modifier" But is this friction modifier already in this latest Castrol oil? No reference to it on the product data sheet. It does say "It is approved for use in the high performance BMW-M Series and Mercedes Benz AMG limited slip differentials." "Approved - MB-Approval 235.61, ZFTE-ML 05C, ZFTE-ML 16G, ZFTE-ML 18, ZFTE-ML 21C BMW LS Rear Axles"

My guess is it will be OK but I thought I would ask here. Btw I also asked Castrol by mail, no reply yet. I will update here when I get an answer. (I think I know what it will be ;-)
Regards, JJW

Glad you are part way there. What does the Mog dealer say ?


GoMog has a dire warning about the wrong oil so I'd be very careful

"WATCHPOINT: Should you read or hear of any advice of ANY other lubricant for these axles, ignore it and sue the writer. (sad smile) In all the years of BTR use, the only failures heard of is from people who ignored this rule.The first sign of failure will be a clicks or light clunk with attitude changes. Damage will commence as soon as the wrong lubricant is used and will continue spreading at a rate depending on what was wrongly chosen. "

Here is what I and a few folk on here in the UK use. I ran on my S1 and now on my 3.7l roadster


They have 2 agents in Holland though the second I guess is the company office.

IWAH Import-Export B.V.
The Netherlands
export@morris-lubricants.co.uk
inKamerseven

Stichting Administratiekantoor
Netherlands
export@morris-lubricants.co.uk
in Hoge Zwalua

Website is here
Good luck.

Morris Lubricants is the little company that the MMC has had a deal with for ages for their oils and lubricants. I imagine they copy the fluids/oil they provide from the component manufacturers specification sheet.but as they don't piublish specific specification sheets themselves, there is no way to confirm. But considering the lack of problems for 30 years, we can be confident. Sadly, they had a limited network overseas, nothing in Canada and only a guy from a basement (IIRC) in the USA. And, of course, such lubricants cannot posted be posted by air.

BTR precisely called for only one lubricant, Castrol SAF-XJ Sadly, Castrol substituted other fluids over time and SAF-XJ became impossible to find. However. the BMW 300 series used a similar BTR and one can pick up the right stuff, very expensively, from any BMW dealer in the world. I am adding the BTR part label below. However, I now see the BTR fluid back https://www.ecstuning.com/b-castrol-parts/castrol-saf-xj-75w140-500-ml/001989520310/

Synthetic 80w140 is no longer a tough fluid to find. The key is the addition of a friction modifier BTR began to use in 1999, after experiencing noises from their axle. It is a bit more technical than that, but one can read more.To end the noise, they used a "friction modifier", I believe from an Italian company called Sturaco. It is sold under many names, even by GM and Ford. So one can buy a high quality 80w140 and add a bottle. But these fluids last so long that it is unlikely a change will ever be necessary. BTR/BMW recommend 50,000 miles (80,0000kms). I change mine at half that. The used fluid always looks hale and hearty.

As long as the BTR specification is followed, the choice is merely a matter of cost price and easy sourcing. You won't get BTR to agree officially but over a pint they will agree.

gmg