transmission serial number

[Hugh]

Here is information regarding odd numbered tranny cases. This is from https://bringatrailer.com/listing/1991-acura-nsx-117/

Hello everyone…
As some may or may not know, the snap ring failure is limited to 1991 – 1992 transmission numbers: J4A4-1003542 – J4A4-1005978.
The snap ring itself is not the problem. The groove in the case was cut too wide in some transmissions, thus allowing the snap ring to twist under load.
Regarding transmissions with an SR8M prefix…
It can indicate both a 5 and 6-speed transmission in the following scenarios:
1. 1991 – 1992 NSXs that had snap ring replacements (likely entire gearbox), the 5-speed transmission that replaced the original one usually begins with SR8M-500xxxx.
2. 1995 – 1996 NSXs (5 Speed transmission) will have a number of SR8M-6100001 – ON FORWARD.
3. 1997+ 6-speed transmissions have prefix (SR8M) but are numbered from 6000xxx-7000xxx.
Thanks…

 

[Bram]

I have not heard of any snap ring issues with transmissions on 93-95 NA-1 cars, especially on the 6 speed transmissions installed on NA-2 cars.

Perhaps, someone have some more accurate information that they can share?

Bram

 

[Miner]

I have not heard of any snap ring issues with transmissions on 93-95 NA-1 cars, especially on the 6 speed transmissions installed on NA-2 cars.

Perhaps, someone have some more accurate information that they can share?

Bram

I believe there is anecdotal evidence on prime of snap ring failures outside of the range. I do believe it is part of the nature of the gearbox, just far more prevalent on the 91-92 boxes in the range.

 

[Lude_2_NSX]

Here is information regarding odd numbered tranny cases. This is from https://bringatrailer.com/listing/1991-acura-nsx-117/

Hello everyone…
As some may or may not know, the snap ring failure is limited to 1991 – 1992 transmission numbers: J4A4-1003542 – J4A4-1005978.
The snap ring itself is not the problem. The groove in the case was cut too wide in some transmissions, thus allowing the snap ring to twist under load.
Regarding transmissions with an SR8M prefix…
It can indicate both a 5 and 6-speed transmission in the following scenarios:
1. 1991 – 1992 NSXs that had snap ring replacements (likely entire gearbox), the 5-speed transmission that replaced the original one usually begins with SR8M-500xxxx.
2. 1995 – 1996 NSXs (5 Speed transmission) will have a number of SR8M-6100001 – ON FORWARD.
3. 1997+ 6-speed transmissions have prefix (SR8M) but are numbered from 6000xxx-7000xxx.
Thanks…

Really helpful post here, the only things that's strange to me is the prefix. The OP and myself seem to have an S4SP prefix. Only two of use have posted with that strange prefix. This supports the "factory replacement" theory, but I still don't know if this mystery has been completely solved with respect to the S4SP transmissions...:frown:

 

[DOHC5]

I purchased a 92 about 6 months ago and the trans code reads SR8M-5000111. Would anyone know if this is a replacement as well? The whole trans or is it just the one side of the case? or the whole case and same internals?

 

[Honcho]

I purchased a 92 about 6 months ago and the trans code reads SR8M-5000111. Would anyone know if this is a replacement as well? The whole trans or is it just the one side of the case? or the whole case and same internals?

There are two ways the snap ring repair was done. First, if the dealer had an experienced NSX tech, they would just replace the upper case. Because the trans code is on the clutch case, these repaired transmissions would keep their original J4A4 numbers. Unless you have service records, there is no way to really know if this was done because the new transmission cases are not numbered in any way.

If the dealer did not trust their mechanic to properly repair the transmission, Acura would just replace the whole thing with a new transmission. Those cars have transmissions starting with SR8M, since new 5-speeds coming off the line used that prefix.

Thus, your 92 has a new transmission as a result of a snap ring repair.

 

[DOHC5]

I greatly appreciate the insight Honcho! Thank you very much sir