Snap Ring Played out topic

[pok8rok8]

Hey guys,

This Snap Ring topic has been read and read and read over and over again. I have asked questions about it numerous times as I know many of you had also.

My question today is this: My car is in Snap Ring range, but the car has 126,000 km on it....My guess is the casing and the ring has lasted this long and should be no problem. I do want to ask the experts here if since I have my engine out and the tranny sitting with it....if I should just change the ring or I should change the casing anyway. Im sure this question is or havent been asked much. Or is it that the snap ring is usually an indistructible item, and only breaks if the case is defective?

[Jimbo]

It's not the snap ring per se.

All indications point to improperly machined casings.

You need to get a new case.

If you have the engine out already I suppose it makes sense to change it now.

-Jim

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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
1976 Honda Accord 5 spd, 3 door Blue/Blue
1977 Honda Accord - Custom - Under Construction
2003 MINI Cooper S - On Order - All Black
1986 Chevy Suburban
http://homepage.mac.com/jimanders/PhotoAlbum1.html

[matteni]

I am sure Jim knows this but you might not understand completely.

You don't need an entire new case - you only need the top 1/2 and other assorted parts. Here is where you can get everything together - and at a good discount too: http://www.daliracing.com/v666-5/cat...cfm?focus=1019

In the FAQ's - here is the important information you need:

1. Transmission (inc. "Snap Ring" failure)
Score: 100
URL: http://www.nsxprime.com/FAQ/Troubles...ansmission.htm

Good luck

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Nick M

91' Red/Black with Many Mods
99' Honda Odyssey with Many Kids

[rrwildman]

I've always been under the impression that one could physically check the snap ring groove clearance to positively determine whether or not a given transmission is susceptible to the related failure. If so, given that only a certain percentage of in-range transmissions are actually susceptible, I certainly wouldn't arbitrarily replace the transmission case. Am I mistaken about that (like so many other things?

Richard
'93 Blk/Blk

[pok8rok8]

Originally posted by rrwildman:

If so, given that only a certain percentage of in-range transmissions are actually susceptible, I certainly wouldn't arbitrarily replace the transmission case. Am I mistaken about that (like so many other things?

Thats the same thing I was thinking....so since I have lots of miles in this car I would think its ok....should I still replace it??

[Jimbo]

I've always been under the impression that one could physically check the snap ring groove clearance to positively determine whether or not a given transmission is susceptible to the related failure. If so, given that only a certain percentage of in-range transmissions are actually susceptible, I certainly wouldn't arbitrarily replace the transmission case. Am I mistaken about that (like so many other things?

It is my impression and understanding that the snap ring groove clearance (dimensions) cannot be easily or readily ascertained. I suspect you could do the inspection if you had a CMM (coordinate measuring machine) but by the time you set up the case and tooling and did the inspection, it would be cheaper to get the case replacement.

There's also well-supported indications that it could not only be the dimensions of the snap ring groove, but other very small dimensions (i.e. radii) or machining finishes associated with the groove.

There have been failed cases sliced open to see the actual cross-section of the groove and it wasn't immediately obvious which dimension was out of spec.

If I had the tranny out and was in a position to correct a snap ring suspect tranny, I'd never use the old case.

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
1976 Honda Accord 5 spd, 3 door Blue/Blue
1977 Honda Accord - Custom - Under Construction
2003 MINI Cooper S - On Order - All Black
1986 Chevy Suburban
http://homepage.mac.com/jimanders/PhotoAlbum1.html

[This message has been edited by Jimbo (edited 23 March 2003).]

[nsxtasy]

I have not heard of anyone accurately measuring the dimensions on the upper transmission case to determine whether or not it needs replacing. Furthermore, to do so, you would need to go through the labor to open up the transmission, which is the expensive part of the repair. What are you going to do, pay for all the labor to open up the transmission without having a new upper transmission case on hand to replace it with?

Also, there have been quite a few reports of snap ring failure with miles as high as 100K miles or more, which is well beyond yours. There is definitely NOT reason to feel immune just because you have put a fair number of miles on your car.

The cost of opening up the transmission and replacing the snap ring and upper transmission case, which will prevent the problem for good, is roughly $630 parts plus $1000 labor. If you are having your transmission opened up anyway - such as for the replacement of the clutch or the installation of gearing mods - this is the perfect time to replace those parts, since you will be paying that labor already, and all you will have to pay for is the parts cost.

Just do it.

EDIT: Corrected parts figure for cost from Dali Racing.

[This message has been edited by nsxtasy (edited 24 March 2003).]

[Larry Bastanza]

You can accurately measure the groove. Trust me I have. The issue is not if you can measure it, but the fact that the groove width is not the problem. The problem is the chamfer, cut on each side of the groove to aid in the snap ring seating properly.

I had developed a jig, about two years ago, that mounts in the case and checks the end play of the countershaft.

This was an attempt to try to "predict" bad cases. After many hours of work, testing multiple transmissions, and spending a lot of time with MB it is clear the groove width is not the issue.

Change the case half and the associated parts in the TSB, as suggested above, while it is apart. You should figure about $600-700 total parts, maybe less depending on your choice of where to get them.

HTH,
LarryB

[nsxtasy]

Thanks for the clarification, Larry.

However, I still can't see the point of spending ten hours of labor to open up a snap ring transmission and measure it, without replacing the parts while you're in there. Even if they LOOK like they're okay, I would replace them and be done with it. In addition to the peace of mind, you'll get back much more than the $630 cost of the parts in resale value when you eventually sell the car.

[Larry Bastanza]

Ken,

I TOTALLY agree, I would not have it out and NOT do the replacement.

LarryB

[rrwildman]

From the sound of it, I'm with you guys. I thought I'd read very credible writeups indicating that one could, with high confidence, determine failure susceptibility by means of checks/measurements done through an access hole in the case, WITHOUT opening the transmission. Evidently I misunderstood, or those were old posts I was reading. If that can't be done then clearly, I'd do the case swap on any in-range box that was already out of the car.

- Richard

[matteni]

Originally posted by rrwildman:
From the sound of it, I'm with you guys. I thought I'd read very credible writeups indicating that one could, with high confidence, determine failure susceptibility by means of checks/measurements done through an access hole in the case, WITHOUT opening the transmission. Evidently I misunderstood, or those were old posts I was reading. If that can't be done then clearly, I'd do the case swap on any in-range box that was already out of the car.

- Richard

There is an Acura TSB on the snap ring issue and it described removing the access cover on the driver's side and inspecting the snap ring itself. There is no way to inspect the groove and predict failure. It is either broken - or it is not.

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Nick M

91' Red/Black with Many Mods
99' Honda Odyssey with Many Kids