52,789 mi....I think the RING on my SNAP just FAILED!!!

[RobD]

It started about 2 weeks ago, while in 2nd gear the gear shift jumped forward out of gear. Hmmm that's strange but everything seemed to be fine after that incident. Yesterday was a beautiful day so I took her out all day and really pushed it at times. I started noticing a low whirling noise in 2nd gear last night on the way home from dinner. This am pulled out of the garage and immediately heard a grinding in reverse...moved to 1st and again heard the grinding....slowly moved to 2nd and the gear shift grinded and popped right out...I wasn't even 2 blocks from home so I turned around and she's back in the garage. NOW....

What's the best way to resolve this...I want to make the Turkey Run in Nov!

I'm going to reach out to Larry B right now and see if he can squeeze me in ASAP.

If Larry can't, I have a great independent Honda shop that has done the some small stuff for me but I want this done right.

What about the Dali Snap Ring Trans kit or the SOS trans repair? If I'm correct then it become more of a bolt off and bolt on type of repair. Your thoughts?



PS-I'm not obsessing about the $$$ to fix it. I got a great deal when I bought the car. At 44 I've learned enough about myself...I can obsess, be miserable and fix it or take it in stride, be thankful I can afford the fix and and move on:biggrin:

 

[Jetpilot3]

Hey Rob...you're much like me in that I too have a snap ring car and if it goes...well it goes.

I'd recommend either Larry or SOS. Have you considered short gears and the 4.23 final drive? I had it on my first 91 and the performance difference from stock was very noticeable.

Short Ratio/NSX-R 4.23 final drive:

http://www.scienceofspeed.com/produ...SX/ScienceofSpeed/transmissions/custom_5-spd/

 

[RobD]

Hey Rob...you're much like me in that I too have a snap ring car and if it goes...well it goes.

I'd recommend either Larry or SOS. Have you considered short gears and the 4.23 final drive? I had it on my first 91 and the performance difference from stock was very noticeable.

Short Ratio/NSX-R 4.23 final drive:

http://www.scienceofspeed.com/produ...SX/ScienceofSpeed/transmissions/custom_5-spd/

I'm actually selling the car to my cousin in the spring and "upgrading" to an 02-05...so I'll offer it to him if he wants to upgrade and I'll cover the stock cost and he cover just the upgrade....otherwise I'm just bringing it to stock for him.

What do you actually pick up in performance by changing the final drive?

 

[Jetpilot3]

Increased off line performance (very noticeable) and shorter gearing so quicker through the gears...

 

[nsxtasy]

What do you actually pick up in performance by changing the final drive?

Not much, less than you would get from minor mods like exhaust and headers:

Stock gears 0-60 5.31 seconds 1/4 mile 13.67 seconds
Short gears 0-60 5.09 seconds 1/4 mile 13.56 seconds
Stock gears with 4.23 R&P 0-60 5.18 seconds 1/4 mile 13.57 seconds
Short gears with 4.23 R&P 0-60 4.98 seconds 1/4 mile 13.48 seconds

However, it will seem like a big improvement because you will reach redline a whole lot faster. But most of that doesn't represent actual improvement because redline occurs at a lower road speed. Time to a given speed or distance isn't all that different, as you can see above.

 

[davidf]

Personally if/when I do the short gears I will leave the stock R&P ratio. I like the idea of the shorter 2nd/3rd for fun factor but I really enjoy my highway MPG's on trips.

 

[davidf]

Here you go:
http://nsxprime.com/forum/showthread.php?t=152854

 

[Honcho]

Rob, so sorry to hear about the snap ring- that sucks man. This is definitely a LarryB level repair- not something you want messed up. The good news is that now it's time for the short gear upgrade. It's too bad you couldn't drive my car before I left LI. In my opinion, short gears plus the stock 4.06 diff is just right. It really transforms the car.

The short gear stack adds about $1000 to the cost of the repair, which is simply a new upper trans case. I do not think the 4.23 is worth another $1000. While he's in there, have Larry inspect and replace anything else that is worn. He did that for me and now my trans is good for basically the rest of the life of the car.

 

[nsxtasy]

Personally if/when I do the short gears I will leave the stock R&P ratio. I like the idea of the shorter 2nd/3rd for fun factor but I really enjoy my highway MPG's on trips.

In case it's not clear to others, the short gears replace gears two through four and do not affect highway mileage while cruising in fifth gear. The R&P gear affects all gears.

 

[RobD]

Rob, so sorry to hear about the snap ring- that sucks man. This is definitely a LarryB level repair- not something you want messed up. The good news is that now it's time for the short gear upgrade. It's too bad you couldn't drive my car before I left LI. In my opinion, short gears plus the stock 4.06 diff is just right. It really transforms the car.

The short gear stack adds about $1000 to the cost of the repair, which is simply a new upper trans case. I do not think the 4.23 is worth another $1000. While he's in there, have Larry inspect and replace anything else that is worn. He did that for me and now my trans is good for basically the rest of the life of the car.

Hey Paul...thanks for the sympathy but I'm not really letting it bother me.
I knew there was a potential SNF in my future. I'm just glad I didnt get stuck in some remote place.

Larry actually got back to me yesterday and is squeezing me in this weekend. I already gave him the green light to replace whatever is needed.

I'm actually waiting for the right LBBP 05 to come along or for Mike B(Arista5) to find his Imola then I'm buying his Silverstone 05. The 91 is going to my cousin so I'm not looking to drop the extra cash into the shorties. I'll ask him if he wants to do the upgrade but he can barely get the car rolling in 1st. He actually drove the car last week and had it stalling and bucking all over the road. It probably aggravated the snap ring

 

[SFNSXguy]

I highly recommend the JDM gears and a low (high number) ratio diff. Much more fun to drive -- street or track.

(He steps to the line... he serves... It's a cross-court lob to keN... :biggrin

 

[ScienceofSpeed]

hi Rob --

Sorry to hear about this.

As you're probably aware, we offer a core exchange program which will allow us to send you a rebuilt transmission with all wear parts replaced (essentially making it like new):
http://www.scienceofspeed.com/produ...SX/ScienceofSpeed/transmissions/custom_5-spd/

This minimizes down time (literally, can be finished in one day).

Alternatively, we could also rebuild your own as well if you prefer.

With nearly 80 NSX transmissions built, we offer excellent experience with the NSX transmission.

Feel free to give us a buzz if you have any questions.

-- Chris

 

[BATMANs]

Not much, less than you would get from minor mods like exhaust and headers:

Stock gears 0-60 5.31 seconds 1/4 mile 13.67 seconds
Short gears 0-60 5.09 seconds 1/4 mile 13.56 seconds
Stock gears with 4.23 R&P 0-60 5.18 seconds 1/4 mile 13.57 seconds
Short gears with 4.23 R&P 0-60 4.98 seconds 1/4 mile 13.48 seconds

However, it will seem like a big improvement because you will reach redline a whole lot faster. But most of that doesn't represent actual improvement because redline occurs at a lower road speed. Time to a given speed or distance isn't all that different, as you can see above.

LOL. That's it?

Like splitting atoms. I rather save up and go for forced induction now as oppose to doing the gears, not being happy with it in terms of acceleration and then spending Forced Induction $$$.

 

[SMYLDOC]

Sorry,.....But think of this as an opportunity to upgrade to JDM short gears which is what I did when mine failed at 110,000 miles....or better yet, a 6 speed which is what I did at 145,000 miles when I did the 3.8 NA rebuild.
I liked the short gears a lot until I got the 6 speed, definitely a very nice upgrade for my daily driver. Just rolled over 180,000 and loving every minute of it!
Good luck

 

[NSX2play]

After many track days with no problems, the snap ring in my 1991 went at 70,000 km (~42k miles) while slowly cruising down the street. Go figure.

But what a blessing that turned out to be. It gave me justification to 'she who must be obeyed' to get an SoS rebuilt transmission with the JDM gears (sometimes incorrectly called 'short' gears when, in fact, only three of the five gears are shorter) and the 4.23 Type R differential. What an improvement! This is the way our NSXs should have come from the factory.

Ken correctly points out that the (estimated) acceleration improvements are not huge (although drag racers will tell you that 2 or 3 tenths ARE huge). But what is not being told by the numbers alone, however, is that the change in the feel and the driving experience are HUGE. My old second gear was sort of an 'it suits every condition' type of gear. It was fine for cruising around town or for buzzing up to the speed limit. But it lacked soul and didn't make me smile. Okay, I always smile while I drive my NSX but now with the new gears and differential my smile is ear to ear. The ratios are so well matched, that the NSX is transformed. Unlike the original setup, it now stays in the VTEC range when shifting from 1st to 2nd. The sporty, racy feel of the NSX is multiplied several fold.

This is, without a doubt, the best modification I have made to my car. Do not hesitate, you won't be disappointed. While you are at it, replace that crappy dual disk clutch with one of the SoS sport clutches that don't chatter and can handle more power, and you will be set.

 

[nsxtasy]

the close ratio JDM gears (sometimes incorrectly called 'short' gears)

It is incorrect to call the JDM gears "close ratio" gears, but it is correct to call them "short" gears.

The JDM gears and the USIM gears share the same first and fifth gears, so the difference in ratios between first and fifth is exactly the same, and neither one has "closer ratios". The JDM set has a closer ratio between first and second; the USIM set has closer ratios between third and fourth, and between fourth and fifth. The second and third shift is almost the same between the two sets.

The JDM gears have shorter ratios for second, third, and fourth gears than the stock gears in USIM cars, hence the moniker "short gears".

Unlike the original setup, it now stays in the VTEC range when shifting from 1st to 2nd.

Not true. When shifting the five-speed at redline, the revs after the 1-2 upshift are 4499 with the stock USIM gears, 5085 with the JDM gears. Both are below the VTEC crossover point of 5800 RPM.

The statement also seems to assume that there is better acceleration above the VTEC crossover point than below, which is not true either. The torque curve for the NSX (shown here) does not show greater torque above 5800 RPM than below. What VTEC accomplishes is, it keeps the torque curve level instead of falling the way it would do without VTEC. This enables the engine to reach higher revs with the same torque, so you don't need to upshift as soon. That gives you better acceleration by keeping you in the same gear, with the acceleration advantage coming from shorter gearing, and not from higher torque.

This gearing advantage is why the JDM "short gears" give better acceleration after the 1-2 upshift (between 40 and 70 mph, when both gearsets are in second gear) and why the USIM stock gears give better acceleration between 70 and 81 mph, when the stock gears are still in second gear while the JDM short gears force you to upshift to third. The short gears give an overall advantage between 40 and 70 mph, whereas the stock gears give an overall advantage above 70 mph.

 

[NSX2play]

When shifting the five-speed at redline, the revs after the 1-2 upshift are 4499 with the stock USIM gears, 5085 with the JDM gears. Both are below the VTEC crossover point of 5800 RPM.

Is this with the NAM 4.08 differential or the Type R 4.23 diff? I was referring to a driveline which has both the close ratio gearset and the Typer R diff which combination, I think, does keep the revs in the VTEC range.

It is incorrect to call the JDM gears "close ratio" gears, but it is correct to call them "short" gears....The JDM gears have shorter ratios for second, third, and fourth gears than the stock gears in USIM cars, hence the moniker "short gears".

If the JDM gears were all numerically higher ratios, they would be the shorter gearset of the two. But they don't, only three of the five are shorter in the JDM gearset, so even the term short gears is not entirely correct.

I prefer the term close ratio since the first to second shift with the JDM gears does not result in as large a drop in rpm as do the NAM gears and from first to fifth there does not appear (to me) to be an aggregate drop in rpm as great as there is in the NAM gears. I have never done the arithmetic to confirm, but suspect you have or will. :wink:

And it still the best mod that I have made to my NSX. :biggrin:

 

[nsxtasy]

Is this with the NAM 4.08 differential or the Type R 4.23 diff?

The revs after each upshift at redline are not affected by which ring and pinion (final drive) gear you use. They're determined only by the difference (ratio) between the gear ratios of the two gears, the one you're shifting out of and the one you're shifting into.

I was referring to a driveline which has both the close ratio gearset and the Typer R diff which combination, I think, does keep the revs in the VTEC range.

Which "close ratio gearset" are you referring to, the JDM short gears or the USIM stock gears? Either way, the revs after the upshift from redline in first to second are below the VTEC crossover point, as noted above. You can still believe otherwise if you like, but this is a mathematical fact, not opinion; 4499 and 5085 are both less than 5800.

As for the terms you want to use (but no one else does so you're only going to confuse people), you can try to engage in semantic arguments and waste a lot of time, but it won't change the ratios of the gears. The spacing of the gears is still as stated above.

I've driven NSXs with the short gears. With their advantage below 70 mph, I think they're fine for driving around town, especially if you're concerned with beating people out in the "stoplight grand prix". For the racetrack, where almost the entire time is spent above 70 mph, it's another story entirely. There, the stock gears are far superior because they provide better acceleration above that point, thanks to their closer ratios. In particular, they allow the use of second gear in twisty portions of the track when you're in that 70-80 mph "sweet spot" where they provide far better acceleration than the short gears do in third gear. The six-speed is an even better solution, better than the five-speed on both the street and the racetrack.

0-70 mph:
'91 with stock gears 6.59 seconds
'91 with short gears and 4.235 R&P 6.12 seconds
'91 with six-speed 6.26 seconds

70-150 mph:
'91 with stock gears 31.19 seconds
'91 with short gears and 4.235 R&P 33.70 seconds
'91 with six-speed 30.08 seconds

 

[NSX2play]

The revs after each upshift at redline are not affected by which ring and pinion (final drive) gear you use. They're determined only by the difference (ratio) between the gear ratios of the two gears, the one you're shifting out of and the one you're shifting into.

Thanks, Ken, as usual your answers are very helpful and eloquent. :smile:

As for the terms you want to use (but no one else does so you're only going to confuse people), you can try to engage in semantic arguments and waste a lot of time, but it won't change the ratios of the gears. The spacing of the gears is still as stated above.

.......and, at times, unnecessarily acerbic.

 

[ChrisK]

I just joined the snap ring failure club last night at 50,0XX miles. I could feel it was getting tough to shift into gears at times, but sometimes it was fine. Last night it was noticeably harder to get into gears more frequently, so when I got home I checked the snap ring and sure enough I had a small piece about 1" from the end of the snap ring that broke off. Looks like Science of Speed will sell another rebuilt trans in a few days. I would have loved to get the 6-Speed or JDM/NSX-R final gear trans which I loved in my first NSX, but at this point I think I'll just get the standard trans, drive the car for a while longer, then sell it for an NA2, or 2002+ NSX.

 

[RobD]

I just joined the snap ring failure club last night at 50,0XX miles. I could feel it was getting tough to shift into gears at times, but sometimes it was fine. Last night it was noticeably harder to get into gears more frequently, so when I got home I checked the snap ring and sure enough I had a small piece about 1" from the end of the snap ring that broke off. Looks like Science of Speed will sell another rebuilt trans in a few days. I would have loved to get the 6-Speed or JDM/NSX-R final gear trans which I loved in my first NSX, but at this point I think I'll just get the standard trans, drive the car for a while longer, then sell it for an NA2, or 2002+ NSX.

Sorry to hear that but we're sharing the same brain. My car is at LarryB's right now being repaired to stock specs. I've already got the buyer lined up for my car. The nice part is, it's staying in my family. My cousin who works with me is taking it. Then I'm buying an 05...I'm waiting patiently for 2 gentleman(they know who they are)to find thier new rides. They each have impeccable examples of an NA2 so either one and I'm very very happy. So to those two gentleman get cracking and find your new cars or my Uncle Vito is going to have to visit and make you an offer you can't refuse.

 

[docjohn]

you hawaii folks don't have a shop local to such work?

 

[NSX2play]

For an excellent thread on this issue that goes into much greater depth and canvasses the pros and cons by some minds much bigger than mine read this.