Snap Ring Casing inspection

[drmikey]

Just about to strip and rebuild a gearbox within the snap ring range

I've searched around on Prime but found no tips on inspecting and measuring the groove tolerances.

Does anyone know the specs, sizes and tolerances of the snap ring groove and step to check if its within tolerance or not?

Thanks

Mike

[Kaz-kzukNA1]

There was no official tolerance for the step so it’s only guess work if judging the OK/NG on the trans case based on any measurements.

Even outside of the so called ‘NSX snap ring range’, the same issue could happen. Seen it on other Honda models as well.

Seems you are doing OH any way, best to replace the case now and do it properly or take the chance and hope it won’t smash the snap ring in the future.
Not all of the gbox within the snap ring range failed so it’s hit and miss as well.

Kaz

[drmikey]

Thanks Kaz,

So no way of measuring the step, or examining how the ring sits, or whether there is any play in the ring when forcing the shaft up and down?

[paulc]

My gears where jumping out of first and second, brought a new snapring, took the gearbox out, took it to a gearbox specialist who cleaned out the disintegrated snapring and put the new one in. The difference is fantastic, gear change is so light. Have now done about 400 miles and touch wood no problems.

The gearbox specialist have warned that a new casing and gear train will be required if the problem occurs again.

[drmikey]

Yes its a transmission case issue rather than the snap ring itself.

If its happened before, likely to happen again unfortunately.

But not every box in the range suffered as it depended where they were machined in the run (i.e when the tool was new, or when it was worn)

New casing is about £800

[Kaz-kzukNA1]

Hi drmikey.
It can be measured but as in my last post, there is no reference in the tolerance spec to say OK/NG. Addition to the case recess tolerance, the snap ring itself has tolerance factor as well.

Probably you can only do the guess work by opening several known good gboxes, measure the recess/step and machine your existing trans case based on the multiple data.
By the time you have done this, I think it would be cheaper to replace the case than going through all these process.

I don’t remember the trans case being so expensive.
When assembling the fresh 6MT (not the 5MT one), I thought it was more of GBP350 – 400 price tag. Obviously, I'm taking about the price in Japan.

If tracking the car and from gear ratio point of view, you may want to stay with 5MT depending on the shape of the track but if you are harsh of the gear shifting, you may want to consider getting later spec 6MT as an option instead of replacing the 5MT trans case or replace the case, overhaul and sell it to recover some of the cost for the 6MT. Early spec 6MT box can be upgraded to the later spec.


Kaz

[drmikey]

Thanks Kaz,

Do you think you could price me up a new casing for your next batch of parts from Japan?

Thanks

Mike

[AR]

Is that for a customer or for you Mike?

[drmikey]

For me. I have a box I've had on the shelf for a while that i want to check and rebuild

[AR]

Are building a special ratios box?

[drmikey]

Thats a lot of questions ;)

No this one will just be a standard overhaul of a 5MT box.