Hello,
Does anyone have any idea what rear differential (if any) there is on the RF MX5 2.0 litre 2017?
I know it does not have the LSD of the manual version but does it have an open differential?
Thanks.
All MX5 automatics, since year 0, have had open diffs.
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The auto box diff is 3.583 and the manual is a 2.866. They may use the same casing but I wonder if the auto uses the NC diff. The Fiat certainly did so it is possible.
If you have an auto why not pop a picture up on here and let us have a look or does some one know the answer.
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Wow; quick responses.
The only reason I ask is when driving on the motorway I did a speed test and for some strange reason it felt a bit loose at the rear end as if it was struggling to put its power down. I could feel it snaking/skating. I did not expect this in a low-powered car.
I am coming though from a Toyota Aygo FWD.
I could take pictures when the weather gets better but where am I looking? Sorry not on top of my engineering.
Thanks.
Doubt itâs your diff. Even in the wet if youâre accelerating WOT in a straight line from say 30mph to 70mph you arenât breaking traction unless you have old/â â â â tires. If the car hasnât had an alignment done in your ownership I suggest getting one.
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Yeah I looked into this, apparently the Bridgestones are no good. They are coming up to some years now old. I only just bought the car from Mazda Used Approved.
Was not wet. Dry conditions.
I would suggest you get a 4 wheel alignment, a bad alignment would give the symptoms you appear to be experiencing.
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⌠for a lightly used car.
OK when new and if they are used a lot, but they âgo offâ far too quickly with age and not enough use.
When I bought my Niseko, 17K miles and six year old Bridgestones with 6mm tread, it was like driving on streaming wet roads; the DSC light was flickering by my knee ALL the time regardless of the road conditions. Scary.
New Dunlop Maxx and happy motoring. These did not âgo offâ anything like so quickly over time, so much so that I kept on putting off a change. The DSC might have stopped working because I never noticed it again!
Similar problem with the 25AE and its ten year old Bridgestones and only 11K miles.
Four new Conti 6 and it is quite simply wonderful.
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Yeah so I picked up a 2017 so that is nearly 7 years old tyres. Only done about 9800 miles.
I have heard good things about the Conti 6 and Michelin Pilot 4 S. Is the Michelin Pilot 5 available now for the MX5?
As I have just bought the car I think I will stick with these tyres and change when legal need arises.
Also this explains that drone noise and slight whine/hiss from the rear of the car when starting and driving at low speed. I think it is the diff; it is so loud though. Seems something wrong with the car. But I think it is the diff. Might have oils replaced. Both for the diff and automatic transmission. As a precaution.
Changing out the old bakelite-hard âlegalâ tyres reduced the road noise dramatically.
The exhaust became audibleâŚ
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Thanks guys responses were great and so many too.
Hope someone can chime in on the diff drone/whine.
I will be careful with this one considering it is RWD. You can feel the weight (feels more heavy towards the rear) and power delivery behind the car and the rear biased seating position. Very different to a FWD car like the Aygo.
Hi W,
You are coming from FWD where you can be quite âaggressiveâ with inputs so you will have to adjust to being much more âgentleâ. Once you get the hang of it you will be fine.
I would get the oil in the diff done as soon as you can. (Some of us change both diff and gear box oil on a regular basis. I am low milage and do it every 3 years.) It is important to get to the bottom of any issues before your warranty runs out. I would certainly take it back and report that you think there may be some issues.
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Hi Mad_Malc,
The oils for the rear open differential and automatic gearbox do not technically/legally need changing according to the service schedule but I will do them. Do you think my local official Mazda dealer will have the oils in stock? If it is not on the service schedule then maybe it is best I order them myself to ensure there are the correct oils to use in the first place.
Regarding reporting back to the dealer I donât think this is anything major? I mean the droning sound is not great but I have heard this is normal and you just hear more things in the MX5 as it has less sound insulation. I mean I could show the noise to my local Mazda service technician; see what he makes of it? Then take it from there. I didnât buy the car local, was quite some distance away.
Good to know though the automatic RF has an open-diff. I assume therefore this is the same diff in the manual 1.5 litre cars? Only the 2L manual (in homura trim?) has the LSD?
Thanks.
This Diff Oil, Genuine Mazda Long Life Hypoid SG1, 1 Ltr, Mk4 & RF â MX5 Parts is the diff oil for manual cars.
Are we sure the diff is the same on auto cars?
You need some more input about the auto gear box oil from those in the know.
All manual 2l cars have the LSD.
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A bit more digging shows this REAR DIFFERENTIALS (NORMAL DIFF.) | Mazda MX-5 Europe 10.2017 | Parts Catalogs | PartSouq so it looks like it is the same casing with just different gear sets within.
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I do know the automatic in the RF is the same as the NC.
Regarding the differential then it seems it is the same as the manual 1.5 Litre cars?
Found the original oil for the automatic transmission.
Mazda JWS3309
Shame I canât find it in the UK. Maybe the official approved dealer will have it stocked.
There is a Mobil make and in the link below it states the Mazda automatic transmissions it can work for but unsure what the code is for the MX5 RF automatic.
Just an update I think Aisin ATF-0T4, Toyota T-IV will also work as automatic transmission fluids. I would rather stick to the orginal Mazda one so hopefully my local Mazda approved dealer has it.
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I wouldnât be worried about the ATF at that mileage.
The differential oil I would change. I think it will be like new, but there is possible myth that they can be underfilled at the factory and that people have drained them and found a few teaspoonfuls of black treacle. Mine was full and clear at 20,000 miles and 5 years so I will do it after another 5.
Whilst it might be alignment, thereâs a good chance decent new tyres would get rid of the squirrelly behaviour. These cars are very sensitive to mismatched, out of shape or unevenly worn tyres and the way they are rotated to even out wear. Also to incorrect pressures.
If the rears have less tread than the fronts, Iâd move them to the front. But donât be surprised if that doesnât fix it.
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This is not a myth. Both our ânewâ NDs were short by some margin as was our friends ânewâ ND. Be warned.
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