I’m looking for technical help or recommendations on: __
Just recently it’s developed a “noise” (a whine?), audible at low speed (Carpark manoeuvres - so 1st and reverse), it may be present at other speeds in other gears, but don’t hear it due to other road noise. I’m suspecting differential, but I imagine it could be gearbox too. The mileage is low (c2500 from new).
I understand the only recommended differential oil is Mazda SG1, and as it’s still under warranty have no desire not to use recommended fluids.
Has anyone else experienced the same with their ND 2.0?
A whine from the gearbox is normal, however it is usually under fairly moderate to heavy acceleration, not pootling around in 1st or reverse. How old is the car? It is recommended to change the differential oil annually (not something Mazda stipulate, but those in the know advise the differential and gearbox run VERY hot and therefore it is recommended), I change my differential every year with Millers Oils 75w90 LS and the gearbox every 2 years with Millers Oils 75w140, I usually do 2500-3000 miles each year depending on circumstances.
Yep, worse when stone cold, and I think it was the LSD, which when manoeuvring at low speeds will drag against the tyre grip. I wouldn’t have described it as a whine, more a rough sounding noise, however I changed the diff oil and no noise since.
I’ve had it on other cars with LSD’s so was pretty sure what it was. Nothing metallic came out when I drained it, although it was a dirty grey sort of colour.
If changing it make sure the new oil is specifically for axles with an lsd, as normal gear oils won’t contain the friction modifiers necessary to enable the lsd to work.
Hi O,
You say it is ‘still under warranty’ so take it to the dealer for their view before doing anything.
Neither of our NDs made any ‘strange’ noises from either gearbox or differential but both differentials were under filled. Apparently they all are. I used the SG1 to top them up.
Thanks for the replies; I had it into the dealers (and checked the noise was present as I reversed into a parking space), they had it in for the day but couldn’t replicate it on road test nor workshop, pronouncing it free of issue. Had I been thinking ahead I would have asked them to change the oil (ho hum), but it’s due an annual service in March/April (and unlikely to see a great deal of use between now and then, and the garage said it’s fine to use as normal), so I’ll ask for gearbox and diff oils changing then.
I noticed it a bit on my 2018 ND1 when it was warmed up at about 40mph, if you accelerated then backed off and accelerated again you could get it whining.
It had done 15k miles and I changed the LSD diff oil with the approved Mazda oil.
One thing I would say is the MX-5 is a small light sports car, not a luxury car, so there isnt much sound proofing, so you do hear a lot more mechanical noise, so it’s likely there isn’t anything wrong with your car, it’s just how they are.
Cheers, and I’m decided on having transmission and diff oils changed at the next scheduled service (if nothing else it would resolve a nagging doubt). I’d agree regarding small lightweight sports car, but the thing I keep pondering on is we’ve had 5, and never experienced this on any others (admittedly, the first MK4).
I’d seen the MX5parts bundle deal, and it’s nice they include fresh crush washers. I’ve previously asked a Mazda technician whether fresh crush washers are used (my father in law - an aircraft engineer - was always adamant that new washers are vital, and in mechanical things he was rarely wrong), and apparently they’re not - since then I’ve either provided my own, or asked that they are.
Agreed.
My NC diff leaked out the fill plug when they were “out of stock” on the new crush washer. The dealer refilled and used new crush washers; no more leak.
You really need to test it at the dealers with you driving it and a mechanic as passenger. Make sure you are hearing the noise and get the mechanic to confirm that they can hear the same noise and whether it is unusual. Limited Slip difs can whine a bit if you are maneuvering the car at slow speed with some steering lock. Does the car make the same noise when you drive straight ahead? Ask to do the same test in another ND2 if they say the noise is normal to confirm whether this is so. Remember you are much closer to the differential in an MX-5 than in a normal car so even the slightest noise will be much more audible.
It’s not steering lock related - does the same even when straight ahead. I did say I’d demonstrate it for a mechanic, but the current covid restrictions preclude it. I’ll change the oil (ensuring I fill it correctly) and see what happens, if they are often under-filled at the factory I could imagine that as the oil thins out it would amplify any noises.
Ah. Mine was noisy only when driven at low speed and manouvering, reversing off the drive or out of a parking space for instance, not in a straight line.
Sorry for the length of time it’s taken to reply; I had to wait for MX5parts to receive replacement stock of the approved diff oil, in the end it coincided with the 2 year service being due so for convenience I’ve waited until then and asked the dealers to change it at the same time (along with crush washers).
Definitely could hear the same noise as I reversed into one of the service parking bays; after the oil change (and admittedly short time in the car afterwards), I think it’s made a difference - couldn’t hear anything reversing out nor trickling round their car park, nor reversing down the driveway after driving home. I think this is resolved - more posts if I find different.
Slight update; I have an acquaintance who specialises in supplying performance oils (a lot for racing/hill climb, but also a lot for a variety of performance cars). I mentioned the ‘filled for life’ nature of the differential and he did some research; his feedback was that like most other differentials it benefits from regular oil changes and the flavour used by Mazda is akin to extra-long life engine
