Let's talk about reliability

[boodjohn]

In more recent news water is wet.

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[Jeff Lange]

FWIW, the S2000 transmission may be made by Aisin (I haven't looked into it), but it is completely unrelated to the transmissions in the 86/FR-S/IS200/RS200/S15/RX8/ND.

Jeff

 

[Nurburgring]

They look similar, but the S2000 using an Aising AZ6 derivative is internet myth. I´ve had them both open side by side when swapping an AZ6 into the AE86.

 

[HKz]

Yes it isn't the AZ6 but it is still an AISIN made box...Honda never had a FR setup prior the S2000 so it would make sense that they would heavily modify an existing gearbox and call it their own.

 

[MA617M]

Fairly confident that the GT86 is it's own Aisin box too, not the same as an S15 unit as the internet widely believes (not in response to anyone here, just trying to dispel myths)

Had one on my desk for many months trying to do a gear kit for it

 

[Jeff Lange]

Fairly confident that the GT86 is it's own Aisin box too, not the same as an S15 unit as the internet widely believes (not in response to anyone here, just trying to dispel myths)

Had one on my desk for many months trying to do a gear kit for it

I'm all about dispelling myths and how hard it can be. (Toyota's internal documentation for the 2016 Tacoma listed an 8GR engine and it took me months or more to convince people it was actually a 2GR and it was just a typo after I was the one who posted the original information! I was correcting myself and I had numerous people tell me I was wrong and used my own posts to prove it, so weird). That said, I've looked into it quite heavily and the S15 is definitely an AZ6 just like the GT86 and the others. There are a few minor differences, but the internals are all of the same design and sizing, etc.

I recently posted details about it on Facebook, including drawings and S2000 stuff. The S2000 uses a secondary reduction gear set and a completely different gear arrangement to the AZ6. Facebook sucks though, so I can't find anything.

This is the S15 FS6R92A transmission gear layout:

This is the SXE10/GXE10 J160 transmission gear layout:

This is the ZC6/ZN6 TL70 transmission gear layout:

Gear ratios for the FS6R92A ( :1):
1: 3.626
2: 2.200
3: 1.541
4: 1.213
5: 1.000
6: 0.767
R: 3.692

Gear ratios for the TL70 ( :1):
1: 3.626
2: 2.188
3: 1.541
4: 1.213
5: 1.000
6: 0.767
R: 3.437

There are major differences in the bellhousing, extension housing and a minor internal differences, but the overall design is the same for both for sure. Many parts are interchangeable (a useful fact given that Toyota/Subaru don't sell a couple of the bearings for the J160/TL70, but Nissan does for the FS6R92A).

Jeff

 

[Jeff Lange]

Yes it isn't the AZ6 but it is still an AISIN made box...Honda never had a FR setup prior the S2000 so it would make sense that they would heavily modify an existing gearbox and call it their own.

But what was the existing box? This is the question.

Jeff

 

[MA617M]

That's fantastic Jeff, thank you!! If you ever feel the need to move to Australia, maybe there'd be a job here in the engineering department for you - because clearly the information I was told wasn't as accurate as hoped.

 

[Jeff Lange]

That's fantastic Jeff, thank you!! If you ever feel the need to move to Australia, maybe there'd be a job here in the engineering department for you - because clearly the information I was told wasn't as accurate as hoped.

Interesting story: I am currently at University getting myself a degree in mechanical engineering and have been looking to do a 12-month internship/co-op work term in the fall of 2019. I've been considering looking for engineering work in Australia and New Zealand (among other places).

Shot in the dark, but if you ever come across someone looking to hire, let me know! Haha.

Jeff

 

[MA617M]

I'll shoot you a pm

 

[Jeff Lange]

Following up, for no real reason, I've been doing further research on the S2000 transmission. Released information from automotive manufacturers rarely state the component manufacturer, or what other vehicles may or may not have used a transmission, still from this release it does seem like Honda played a major role in designing the S2000 transmission.

Six-speed manual gearbox allows rapid shifting

A compact six-speed close-ratio manual transmission enables the driver to fully exploit the HONDA S2000’s engine to the full, while a low-inertia flywheel and lightweight gears ensure that its willingness to rev is not compromised. The gearbox, with integral oil pump, is designed specifically for the HONDA S2000 and shares no common components with the six-speed NSX manual transmission.

With the engine already moved as far back in the chassis as possible, space for the transmission was at a premium, so Honda engineers designed the transmission to be as narrow as possible. All six speeds and reverse are on two parallel shafts.

Both transmission shafts are coupled at the output end, a design feature borrowed from Honda's front-wheel-drive transmissions. This reduces the load on the gear synchronisers by as much as 40 per cent, which, in turn, allowed the gears to be smaller.

The use of the secondary output gears is a strategy Aisin would later employ in the AY6 transmission. Both utilize what is known as a tail-set arrangement where the gears are on the input shaft and the output shaft is short (vs. the common head-set arrangement that uses a short input shaft and a long output shaft). This arrangement spins the countershaft quicker, reducing the amount of torque applied to the gears and shafts and then has a final reduction from the counter shaft to the output shaft. The required gear faces can now be narrower, resulting in a smaller transmission for the same torque capacity.

The obvious downside is that when engaging gears you need to get them spinning more quickly. This puts more work in the hands of the synchro rings, a known issue on early AY6 transmissions (2005-2006'ish).

Often times with transmissions that use a tail-set design, you will find that there is no gear that provides a 1:1 ratio, and that is true for the S2000 as well, the closest being 5th at 0.970:1. (Though this isn't the case on the AY6).

So who designed the S2000 transmission, and who built it? Was it all Honda? Was it Honda designed and Aisin-built? Was it all Aisin with specs from Honda?

Jeff

 

[DesmoSD]

BMW fires

Do you think this will affect the MKV?

https://abcnews.go.com/US/mysterious-bmw-fires-continue-calls-investigation-grow/story?id=60843215

 

[XtremeMaC]

it's super shitty, but it seems they are older models as far as I can tell. let's hope they remedied on newer models. gotta research 2017+

 

[kona61]

BMW fires

Do you think this will affect the MKV?

https://abcnews.go.com/US/mysterious-bmw-fires-continue-calls-investigation-grow/story?id=60843215

I mean, the 540i, 335i, 135i, M3, other M3, or 328i that were in my family at different times ever caught fire. I am certain many of these issues stem from outside sources such as wiring corrosion/damage or neglected maintenance.

 

[Bryster]

BMW fires

Do you think this will affect the MKV?

https://abcnews.go.com/US/mysterious-bmw-fires-continue-calls-investigation-grow/story?id=60843215

I don't think so, the recalls seem to be for N Series BMWs

 

[Therealist]

For the sake of fairness:

https://www.reliabilityindex.com/manufacturer

Toyota rank 4th

BMW rank 31st

On the car list:

https://www.reliabilityindex.com/top-100

Toyota IQ ranks 1st

BMW does not appear on the top 100

This is why I don’t like BMW anymore and from personal experience. 2 blown engines later, never again. I still have the last one but only because it’s not worth selling after the amount spent fixing it....

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