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Rough shifting

Joined
1 February 2005
Messages
108
Location
Dallas, TX
I have a 2000 NSX with 14.3K miles on it.
I have noticed over the last week or two that when I engage into gear, it sometimes feels somewhat rough getting into gear (sometimes, not always). Not sure how to describe this, but what I mean by rough is that it feels like when you're riding a bicycle and you shift gears, and you feel like the gears need some oil. Prior to this, shifting has always been smooth for the last 3-4 months.
Well, I figured it was around the 15K service time, so I brought in my car to Goodson Acura to have the service done and I asked them about the shifting. My thinking was that this may be related to needing a transmission fluid change.
Well, they changed all the fluids and the tech said that they notice that many owners complain of rough shifting with their NSXs,and they noticed absolutely no problems with mine.
Taking it home, I still felt that it shifted roughly occasionally... nothing bad, but just like it could be better.
I'm just wondering if anyone out there also feels that their NSXs shift roughly... and if there is anything that can be done... Or am Ijust being overly sensitive to my car???
Thanks!
 
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You may need some energy to put in gears in a NSX but not too much - ever tried a stick in a Ferrari F 355? Now that's much.

The only problem that may occur is a worn clutch or a bad throwout bearing which makes gearing harder - try to change gears with engine off - is it smoother?
 
It seems to be the same with the engine off....
 
My 98's gearbox is really temp. sensitive. It's our weekend car so it sits in the garage under cover M-F. I find that my shifts into second (for the first few miles of driving) are "rough" and I have to be careful not to grind sometimes. Once the gearbox is warmed up... it's smooth as butter.

And for the record, I had just had all the fluids changed less than 500 miles ago (about two months).
 
I think that at times I have experienced what you are describing. When I upshift sometimes for example second to third I feel a slight thud in the rear when I let the clutch out to engage. This isn't all the time and it really isn't severe at all. I'm just wondering if this may be related to what you are describing. The actual task of shifting is fine it is just that when I am in the gear that I am upshifting to and I let the clutch out there is slight thud. Related? Not to sure? :confused: By the way I have a 91 with 75k miles on it.
 
Ironically, this post came up as I was contemplating changing my manual trans oil. I was thinking of trying the Royal Purple Synchromax to try to eliminate some of the rough shifting. I only get it once in a while when the trans is cold. Anyone try this yet?
 
Sean Williams said:
Ironically, this post came up as I was contemplating changing my manual trans oil. I was thinking of trying the Royal Purple Synchromax to try to eliminate some of the rough shifting. I only get it once in a while when the trans is cold. Anyone try this yet?

I have never tried it but I would definitely be interested as I use their synthetic motor oil and absolutely love it. Does their transmission oil have to be special ordered or can you find it as easy as the engine oil?
 
Stunner said:
Does their transmission oil have to be special ordered or can you find it as easy as the engine oil?

Good question. I see their motor oil at a lot of shops, but haven't noticed the trans oil. Before I start calling some distributors regarding the trans oil, I e-mailed Royal Purple and asked them which product we should be using in our manual trans NSXs, the Synchromax or the 10W30 like the service manual states. On their web site they have a transmission cross reference which indicates 10W30 for Honda/Acura MT, but they also state that Synchromax can be used in a trans requiring motor oil. I was a little confused, so we'll see what the say. I hope they recommend the 10W30, because it is easy to find. I'll keep you posted.
 
I have a 93, and the shifting was pretty rough when I first bought it.
I changed the transmission fluid to Redline MTL, and it really solved the shifting problem. Not sure if this is the case with your X, but it sure solved my problem.
Also, you can try a longer shiftknob, it makes shifting a bit easier.
 
Royal Purple got back to me and said they recommend 10W30. I'll be trying it soon and let everyone know how well it works.
 
Sean Williams said:
Royal Purple got back to me and said they recommend 10W30. I'll be trying it soon and let everyone know how well it works.

Great! I need to change out my transmission fluid soon so definitely keep us updated. How much are you going to end up spending for the oil?
 
Try some GM synchromesh transmission oil, I absolutely swear by it . My 91 Nsx shifts better than my S-2000 did. Do a prime forum search on the topic you'll see a lot of testimonials.
 
Da Hapa said:
My 98's gearbox is really temp. sensitive. It's our weekend car so it sits in the garage under cover M-F. I find that my shifts into second (for the first few miles of driving) are "rough" and I have to be careful not to grind sometimes. Once the gearbox is warmed up... it's smooth as butter.

And for the record, I had just had all the fluids changed less than 500 miles ago (about two months).

Yeah, I also use it pretty much weekend car only.. and I appreciate hearing your experience and it makes me feel mine may be related to not being warmed up.. its definitely most noticeable with shifts to second and third...
 
Stunner said:
I think that at times I have experienced what you are describing. When I upshift sometimes for example second to third I feel a slight thud in the rear when I let the clutch out to engage. This isn't all the time and it really isn't severe at all. I'm just wondering if this may be related to what you are describing. The actual task of shifting is fine it is just that when I am in the gear that I am upshifting to and I let the clutch out there is slight thud. Related? Not to sure? :confused: By the way I have a 91 with 75k miles on it.

This seems different from my experience. My experience is the shiftknob feels rough getting into the position of the gear, while the clutch pedal is depressed. Once it is in gear, and I release the clutch pedal, it shifts smoothly and I get smooth power. I never feel any slight thud - I wonder if what you're describing is more of a clutch issue (?perhaps related to releasing the clutch too quickly??), rather than a shiftknob issue.
 
heard lots of good things about GM Synchromesh. Not sure if it helps with the rough shifting, but it definitely got rid of my friend's (NSXDreamer) grinding problem when shifting into third gear at high rpm.
 
freelance201 said:
heard lots of good things about GM Synchromesh. Not sure if it helps with the rough shifting, but it definitely got rid of my friend's (NSXDreamer) grinding problem when shifting into third gear at high rpm.


My 91 had a slight grind going into 3rd gear and in general was very notchy,I refilled with GM synchromesh and immediately drove the car . I was disgusted because it didnt have any effect initially,then a couple of days later the grind was nowhere to be found ! And it started shifting like silk.
 
Stunner said:
How much are you going to end up spending for the oil?


I think my local shop carries a case of it (10W30) for around $70. I figure I'll do the engine oil change and trans at the same time.
 
Sean Williams said:
I think my local shop carries a case of it (10W30) for around $70. I figure I'll do the engine oil change and trans at the same time.

I can get Royal Purple at Pep Boys here, but anywhere else I have tried doesn't have it surprisingly. I checked and they didn't stock the tranny oil so I guess I am looking at ordering it. Redline products are practically unheard of here and nobody I know carries it... So frustrating.. :mad:
 
Aside from mechanical issues, number one reason for “rough shifting” is low transmission fluid level.

A lot of people overlooked the fact that the transmission fluid level should be checked under normal operation temperature (warm/hot). Fluid level is actually low if you top it off at ambient temperature. From my experience, after replacing the fluid, you need to drive around until the transmission is at normal operation temperature and then top it off while the transmission is warm.

If anyone of you experience “rough shifting”, check the fluid level before doing anything drastic.
 
If memory serves, I believe someone lost a transmission due to Royal Purple a while back. I seem to remember that Royal Purple claimed their transmission oil was not designed to be used in an NSX transmission (whatever that means). I use the motor oil and like it fine though. Perhaps someone can do a search for an old thread with Royal Purple and transmissions.

S.L.
 
V12NSX said:
If memory serves, I believe someone lost a transmission due to Royal Purple a while back. I seem to remember that Royal Purple claimed their transmission oil was not designed to be used in an NSX transmission (whatever that means). I use the motor oil and like it fine though. Perhaps someone can do a search for an old thread with Royal Purple and transmissions.

S.L.

Here's that thread

Makes me have second thoughts about using it as trans oil.
 
Zennsx said:
My 91 had a slight grind going into 3rd gear and in general was very notchy,I refilled with GM synchromesh and immediately drove the car . I was disgusted because it didnt have any effect initially,then a couple of days later the grind was nowhere to be found ! And it started shifting like silk.

People who swore by the GM Snake oil recomment using 2 bottle of GM Friction modifier and one GM synchromesh... I bought 7 bottles total, and I messed up and had 2 GM synchromesh with 1 friction modifier. I noticed the shifter had the buttery feel when cold, but my Hub selector still grinds... :redface: 2-third gear shift. Driving it for more than a month, it gets better but no noticeable difference on the problem I have.

Took it to one track day, but the time I got out in second session, I can shift faster and earlier with direct feel and no more grinding at 8000rpm. :biggrin: Except being a little norchy (2-3) shifting at redline... I had a completely perfect transmission... :biggrin:

Highly recommended.
 
Stunner said:
I think that at times I have experienced what you are describing. When I upshift sometimes for example second to third I feel a slight thud in the rear when I let the clutch out to engage. This isn't all the time and it really isn't severe at all. I'm just wondering if this may be related to what you are describing. The actual task of shifting is fine it is just that when I am in the gear that I am upshifting to and I let the clutch out there is slight thud. Related? Not to sure? :confused: By the way I have a 91 with 75k miles on it.

From what you describe, I think I have had this problem too. When I learned how to drive a stick on my mom's Focus, which the engine doesnt rev up or down very quickly, I got used to shifting slowly. When my dad got his NSX and started letting me drive it, I had that slight thunk with every upshift. Its nothing wrong with the clutch or transmission, you just have to shift a little quicker and make sure you let the clutch out before your RPMs drop too low. Also, feed in a little throttle while you let the clutch out. This might be your problem. Just look at your tach while you upshift. If your RPMs drop when you let of the gas and push the clutch, then jerk back up a few hundred RPM's as you let the clutch out, you just need to shift quicker. You've probably know about rev matching on downshifts, this is pretty much the same thing, only instead of revving it up to get the right RPM, you have to time the clutch release at the right RPM.
 
I decided to go with the Honda MTL instead of the Royal Purple 10W30. On a side note, Royal Purple e-mailed me twice saying to use their 10W30 instead of the Synchomax stuff. Anyway, the Honda MTL made a noticeable difference in shifting, not as notchy as before.
 
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