NSX differential

[NoelWatson]

Anyone know what type of diff my 2004 coupe manual car has? Reason I ask is that my car was unable to pull away on an incline on the way home yesterday. The left wheel was on leaves and was spinning. The right was doing nothing. I am thinking it is a torsen type diff - if so I should've used the handbrake to transfer torque.

After 11000 miles, I think my RE040s on the rear have seen better days.

[NSXGB]

Sounds very strange. Firstly the LSD should have transferred power from the spinning wheel to the other side and then if either of the wheels are still spinning the TCS should have atempted to help (if you had it on).

[NoelWatson]

Sounds very strange. Firstly the LSD should have transferred power from the spinning wheel to the other side and then if either of the wheels are still spinning the TCS should have atempted to help (if you had it on).

The LSD did help, but we were on an incline so not enough torque was transferred (if I remember correctly, torsen types have a max transfer ratio i.e 4:1). Traction control (for later cars) is very aggressive - good for saving hamfisted drivers, but not good for pulling away on slippery surfaces. Had a similar problem back in April in the snow.

[simonprelude]

My Merc did the same yesterday :(

[markc]

I'm pretty sure it's not a Torsen diff. Torsen diff are not usually fitted to RWD cars as they're better suited to FWD or 4WD cars.

I don't think they changed the diff type for the 02+ cars so it should be a traditional LSD with friction clutches transferring the power when one wheel starts to spin.

This type of LSD relies on input torque (from the engine/gearbox) and driveshaft load to "lock" the output to both wheels though clutches which are fitted to each driveshaft. The torque/load causes the friction clutch packs together thus driving both wheels.

The NSX LSD is not a tight one (like the ones fitted to the S2000) so does allow some slip between wheels. Your description does sound quite extreme though. The clutches eventually wear out and require replacing or reshimming to restore correct operation.

When was the gearbox/diff oil last changed? Might be worth having it changed as it effects the operation of the diff.

Cheers

Mark

[NoelWatson]

I'm pretty sure it's not a Torsen diff. Torsen diff are not usually fitted to RWD cars as they're better suited to FWD or 4WD cars.

I don't think they changed the diff type for the 02+ cars so it should be a traditional LSD with friction clutches transferring the power when one wheel starts to spin.

This type of LSD relies on input torque (from the engine/gearbox) and driveshaft load to "lock" the output to both wheels though clutches which are fitted to each driveshaft. The torque/load causes the friction clutch packs together thus driving both wheels.

The NSX LSD is not a tight one (like the ones fitted to the S2000) so does allow some slip between wheels. Your description does sound quite extreme though. The clutches eventually wear out and require replacing or reshimming to restore correct operation.

When was the gearbox/diff oil last changed? Might be worth having it changed as it effects the operation of the diff.

Cheers

Mark

http://www.nsxprime.com/forums/showthread.php?t=92820&highlight=torsen

http://www.nsxprime.com/forums/showthread.php?t=84136&highlight=torsen

So I think both pre and post 97 cars use clutch plates as you say, but with slight differences. I will get all fluids changed at my next service - not sure when this was last done.

[Kaz-kzukNA1]

Just a follow up. This is what inside your LSD.
4657
As Mark stated, it is based on multiple friction disks (clutch) and not the ‘Torsen’ one.
These disks are soaked in the MTF and as NSX has quite small oil capacity considering its performance and with the ingenious way of circulating the oil for the mechanical parts inside the GBox, the MTF needs to be looked after very well.

Depending on how you drive the car, these disks will eventually wear out and loose the original locking torque. What you experienced was exactly the tendency of standard NSX LSD. The one on Type-R got higher locking setup.

If you have a big socket and torque wrench, you can check the status of your friction disks and understand the torque required to break the locking. You may find it quite low but servicing of LSD requires SST...

Regards,
Kaz

[NoelWatson]

Just a follow up. This is what inside your LSD.
4657
As Mark stated, it is based on multiple friction disks (clutch) and not the ‘Torsen’ one.
These disks are soaked in the MTF and as NSX has quite small oil capacity considering its performance and with the ingenious way of circulating the oil for the mechanical parts inside the GBox, the MTF needs to be looked after very well.

Depending on how you drive the car, these disks will eventually wear out and loose the original locking torque. What you experienced was exactly the tendency of standard NSX LSD. The one on Type-R got higher locking setup.

If you have a big socket and torque wrench, you can check the status of your friction disks and understand the torque required to break the locking. You may find it quite low but servicing of LSD requires SST...

Regards,
Kaz

Kaz,

Thanks for that. Not sure when my tranmission oil was last changed - I don't know when it comes up in the servicing schedule.

[Ewan]

Kaz,

Thanks for that. Not sure when my tranmission oil was last changed - I don't know when it comes up in the servicing schedule.

Noel: from memory, it's at the 6 year interval. Last service for me (5 years), I bought new transmission oil from OpieOils and got them to replace it because I was getting a notchy shift from 1st-2nd when cold. Replacing the oil made a bit of a difference though it's still a bit clunky at first.

cheers
Ewan

[NoelWatson]

Noel: from memory, it's at the 6 year interval. Last service for me (5 years), I bought new transmission oil from OpieOils and got them to replace it because I was getting a notchy shift from 1st-2nd when cold. Replacing the oil made a bit of a difference though it's still a bit clunky at first.

cheers
Ewan

I was going to ask about what I would need to a full fluid change after seeing OpieOil's latest offer. So in addition to engine oil and transmission fluid, is there anything else?

[nigel]

Try a fliud change and this time use the "Honda" brand "white cap" MTF. It should help with the notchiness and smooth your shifting all round. As Kaz said, it might be time to overhaul the LSD from lack of lockup pressure but it seems WAY to soon unless the car has been floged on the track or something in its past you don't know of. Still seems to soon for all that.

Cheers
nigel

[Kaz-kzukNA1]

Just a note on the transmission oil.

..... as NSX has quite small oil capacity considering its performance ....
Only 2.8L for such a high performance car (on MT, rev limit starts at 8,000rpm:)). This is really small compared to other high performance sport cars.

As this post is for the NSX differential (DF), I don’t want to go too much in detail but...

..... with the ingenious way of circulating the oil for the mechanical parts inside the GBox, the MTF needs to be looked after very well.
If you have a chance to look at the inside of the gbox, there are hollow section on the main, counter and reverse shaft. There is a meshed strainer (filter) and standard impeller type oil pump. This pump is driven by the DF. Yes, it’s by the DF and that means, the oil won’t be pumped around the gbox until the car has started to move.
In order to provide the mechanical parts with enough oil using such a small oil capacity under high rpm, the oil is actually pumped through inside the hollow section of the main, counter, reverse shaft and the passage on the gbox case.
Because of this design, the transmission oil for NSX requires soft viscosity with strong oil film. In fact, when NSX was first introduced to the market, it was recommending 10W-30 Eng Oil (quite soft) or Honda MTF as the transmission oil. I have the Honda MTF-3 and other aftermarket transmission oils in my garage. Compared to these other brands, you will be surprised to see how soft the Honda MTF is even in the cold winter. It dances like a water (may be too exaggerated...) inside the container.
So, if you put high viscosity transmission oil on NSX (like some of my friends), then quite often, you’ll notice notchy/stiff feeling on 1st/2nd gear on cold winter morning. On leaving the garage, you won’t notice it because the DF is not moving and thus no hard oil is delivered to any part of the gbox. Once you started to move, the DF/pump would try to circulate the very cold and hard oil causing the notchy/stiff shift. Eventually, the heat from the engine will be transferred to the gbox case and the rotating gears will raise the transmission oil temperature and thus, no more nothcy/stiff feeling. Obviouly, this is presuming that you don't have any mechanical failure as transmission oil won't be able to cure it.

So, unless you track the car, it is recommended to use Honda MTF-3 (I think this is the latest version) for your transmission oil. It is a very good and thought after oil. You can easily get it from your local Honda dealer. If you use your NSX on the track, depending on the shape of the track and the temperature, you may notice changes in shift/DF feeling within a short period... It’s getting too hot :eek: and thus you may want to search for the aftermarket oil with the trade off of nochy/stiff feeling in the winter.

Regrds,
Kaz

[dan the man]

Yup Honda MTF always been the bestb option on all honda forums for various hondas.

[Ewan]

Here's what I got from Opie last time...


Oil and Filter Service Pack HONSP24484
SKU: HONSP24484
x1

REDLINE Synthetic Manual Transmission Lubricant 75W/80w GL4 -1 x US Quart (0.946L)
SKU: REDMTL-1
x3

cheers
Ewan

[Papalazarou]

I tried at my local Honda garage and they couldn't get MTF4. I then spoke to the Honda UK technical guy and he said it's not imported into the UK by Honda.
I'd really like to try this product because I've heard some really good things about it.


Cheers,


James.

[TheSebringOne]

James, I thought you worked in a car related industry? So could easily source MTF or lubrication oils etc? Didn't you previously sell or adviced on Wyns products? Correct me if I'm miles off or just say nope? :)

[Papalazarou]

James, I thought you worked in a car related industry? So could easily source MTF or lubrication oils etc? Didn't you previously sell or adviced on Wyns products? Correct me if I'm miles off or just say nope? :)

I can definately get a variety of different products through the trade, but the stuff I've tried so far didn't help the notchiness when the car is cold so I wanted to try the MTF4 to see whether it was any better.


Cheers,


James.

[Kaz-kzukNA1]

Hi, James.
As you already checked with Honda UK, it seems that the latest MTF on the market is MTF-3. That is what I have in my gbox at the moment and as in my post, it is a very good oil for street and light track usage. Just try it as it is not that expensive for just about 3.0L from Honda. I think it was about £7 per litre...

Regards,
Kaz

[nigel]

The latest generation of MTF from Honda has a "white" cap.
It does smooth the gearbox and won't effect the sycronizers adversly. Some of the friction modifiers will smooth the gear box but at the cost of prematurly wearing the syncros.

Cheers
nigel

[Papalazarou]

The latest generation of MTF from Honda has a "white" cap.
It does smooth the gearbox and won't effect the sycronizers adversly. Some of the friction modifiers will smooth the gear box but at the cost of prematurly wearing the syncros.

Cheers
nigel

Hi Nigel,

I guess the latest MTF may be the way to go, but why would a friction modifer wear the synchros?


Cheers,

James.

[duncan]

If Honda specify a 10W30 or 10W40 'engine' oil, why would you put a 75/80 ,transmission' oil in?
The LSD for the pre 1995 M/T [5 speed] plus all years A/T compared to the 1995 on M/T [both 5 and 6 speeds] are very similar; the sun wheels are an enclosed set and are sandwiched between two clutch packs in the diff case, all lubricated by the gearbox oil. The later M/Ts have less plates/clutches in the sandwich but have in-lieu thrust races against the case itself. So whether the sun wheels have a 'torsen' style helical twist or not, the diff is relying on these 'wet' clutch packs to lock the diff.
My assumption being that as the diff spins the oil/ clutches heat and then lock, in a similar fashion to the steel on steel expansion of bellville washers in a Salisbury style 'Powr-Loc' LSD.
As Honda specify the gearbox and hence diff oil as 10/30 or 10W/40 'engine' oil, as opposed to [say] Castrol LS or B373, the plates/clutches have presumably been so engineered and optimised. A different grade or style of oil, or oil additives will surely alter the bite character of the diff.
So......10W30 or 10W40 SF or SG grade every 2 years......

[Silver Surfer]

If Honda specify a 10W30 or 10W40 'engine' oil, why would you put a 75/80 ,transmission' oil in?
The LSD for the pre 1995 M/T [5 speed] plus all years A/T compared to the 1995 on M/T [both 5 and 6 speeds] are very similar; the sun wheels are an enclosed set and are sandwiched between two clutch packs in the diff case, all lubricated by the gearbox oil. The later M/Ts have less plates/clutches in the sandwich but have in-lieu thrust races against the case itself. So whether the sun wheels have a 'torsen' style helical twist or not, the diff is relying on these 'wet' clutch packs to lock the diff.
My assumption being that as the diff spins the oil/ clutches heat and then lock, in a similar fashion to the steel on steel expansion of bellville washers in a Salisbury style 'Powr-Loc' LSD.
As Honda specify the gearbox and hence diff oil as 10/30 or 10W/40 'engine' oil, as opposed to [say] Castrol LS or B373, the plates/clutches have presumably been so engineered and optimised. A different grade or style of oil, or oil additives will surely alter the bite character of the diff.
So......10W30 or 10W40 SF or SG grade every 2 years......

:overhead:

SS

[NSX 2000]

:overhead:

SS

SS I think I might just second that.

Paul.

[NoelWatson]

If Honda specify a 10W30 or 10W40 'engine' oil, why would you put a 75/80 ,transmission' oil in?
The LSD for the pre 1995 M/T [5 speed] plus all years A/T compared to the 1995 on M/T [both 5 and 6 speeds] are very similar; the sun wheels are an enclosed set and are sandwiched between two clutch packs in the diff case, all lubricated by the gearbox oil. The later M/Ts have less plates/clutches in the sandwich but have in-lieu thrust races against the case itself. So whether the sun wheels have a 'torsen' style helical twist or not, the diff is relying on these 'wet' clutch packs to lock the diff.
My assumption being that as the diff spins the oil/ clutches heat and then lock, in a similar fashion to the steel on steel expansion of bellville washers in a Salisbury style 'Powr-Loc' LSD.
As Honda specify the gearbox and hence diff oil as 10/30 or 10W/40 'engine' oil, as opposed to [say] Castrol LS or B373, the plates/clutches have presumably been so engineered and optimised. A different grade or style of oil, or oil additives will surely alter the bite character of the diff.
So......10W30 or 10W40 SF or SG grade every 2 years......

"My assumption being that as the diff spins the oil/ clutches heat and then lock, in a similar fashion to the steel on steel expansion of bellville washers in a Salisbury style 'Powr-Loc' LSD. "

I don't think this is the case - the above to me sounds like a viscous coupling.

[duncan]

Definite answer anyone?;
if they were viscous then the discs could be paddles or vanes?, that they are clutches and plates made me think friction.
Whatever......the answer is MTF-3 or an equivalent?....
My final thought could you re-shim the clutch packs to a tighter assembly to either compensate for wear or to induce a more aggressive inital lock up?

[forumadmin]

Engine oil for the gearbox? Try it. Kowalski had it in his for a while and it made the car undriveable. The diff was locked solid.

Shimming and tightening up the diff is exactly what the Type R version is. Either the standard diff is loose, or after a while is not effective. I could spin an inside wheel at a track at will, with a trail of smoke behind me.

I have an OS Giken diff now. The spinning wheel syndrome has stopped but it is an odd drive on the road. It definately applies more lock as more power is applied (unlike the old diff). Halfway through a corner on the road, if I apply more throttle then the car straightens up. It's slightly worrying that its going to spit you into oncoming traffic on the other side of the road. At slow speed to get into parking spaces, or exits from junctions, it will have the car jumping as the clutch plates are forced to disengage. The amount of power that is now put to the road exiting bends on the track caused the clutch to start to slip. Everything has a side effect.

I thought just having both axles connected by a set of clutches just means there will be a small amount of torque applied to both wheels. Or, in other words if one wheel is in the air, the other will have the same amount of torque applied to it, the same as it takes to disengage the clutches. As the clutches take 100 lb/ft or so to break, then that amount of torque will always be applied.

[NoelWatson]

I'm pretty sure it's not a Torsen diff. Torsen diff are not usually fitted to RWD cars as they're better suited to FWD or 4WD cars.



I think the S2000 has a torsen (according to Wikipedia)

[Ewan]

... and http://corporate.honda.com/press/article.aspx?id=4096

[kowalski]

As Kevin mentioned, I had Engine Oil put in mine during a clutch change. The Diff seized up within a couple of days and the car was a nightmare to drive. It took 3 flushes of MTF3 to bring it back to normal.

The fault lay with the early service book which did say you could use Engine Oil, this was changed in later service book revisions.

Not recomended

leigh