Snap ring fixed, total cost...£3.50

[mutley]

HI guys,

Now you can all relax knowing that I'm going to stop whining about having no first gear and a wiggle second gear as I have finally fitted the new snap ring into my gearbox, got the car back together and YABADABADOO it all works absolutely perfectly!!!

Total cost £3.50

Anyone need any info on how to do this, PM me or e-mail or call whatever, the job is a pain in the backside but looking back not really that difficult, the hardest part was removing/refitting the box.

Cheers

Jim

[rkanaga]

Great job!

One question, how quickly did you stop driving when it broke?

The horror stories are about the internal damage done by driving on once the snap ring has fallen in bits into the transmission necessitating at least a partial rebuild (the bits of broken ring can apparently really mess up the internals)

If your experience suggests that there is the option just (!) to fix the ring provided it is picked up quicky then many of us with early cars would sleep a bit easier!

Robin

[mutley]

Great job!

One question, how quickly did you stop driving when it broke?.................

..................If your experience suggests that there is the option just (!) to fix the ring provided it is picked up quicky then many of us with early cars would sleep a bit easier!

Robin

Hi Robin,

Well if you've seen my earlier posts, you'll know that not long after I bought my car (about 3-4 months) the clutch started slipping BADLY then one day the release bearing decided to explode, so having taken the box off to do the clutch, I wondered how easy it would be to see if I had the notorious broken snap ring, answer YES I did.

I too heard of the horror stories, and I though that my 1st gear problem was related to the clutch as they both got worse at the same rate. Anyway as the box was off the car and new clutch fitted, we opened it up to find out how "easy" it would be to replace the snap ring (and YES with the casing off found lots of bits of snap ring in the many recesse) but luckily most of the snap ring had jamed in the groove in the casing so I must say that very little damage had been done to the cogs.

I would advide that you don't drive at all, or at least very carefully if the snap ring does go, but apart from the hassle of the work, a very cheap repair for what could end up costing a new gearbox, Snap ring =£3.50....Second hand gearbox approx £1400.

With the new snap ring in place, the box feels new, sometimes first and reverse needs a little extra effort to get in, but that may be me being used to the way it was.
Out of interest my car has done about 97K.

If anyone needs more info, give me a shout.

Jim

[Accelera Comigo]

Where's the snap ring and what does it do? Do any of you have photos of the repair work you did?

AC

[NSXGB]

Where's the snap ring and what does it do? Do any of you have photos of the repair work you did?

AC



....this has been covered in depth on www.nsxprime.com (http://www.nsxprime.com) and I believe there are photo's in the FAQ.....

[AR]

Congratulations not only are you skillful but really lucky it did not mess up your transmission when it broke.

Cheers,

AR

[megahertz]

excellente!! congrats! i've just heard horrid stories bout The Snapring issues...

[mutley]

Thanks for your comments guys,

Looking back now, maybe I was lucky that the clutch went at the same time, so I had no option but to put the car of the road, and meant that I didn't do many miles in that condition. I have said this in another thread, but as most of us know the original problem (reason what the snap ring breaks) would appear to be a problem with the casing. I plan to do a fair bit of mileage next year (see ya all at japfest!!) and I'll see ow this new snap ring holds up, if it does, bonus, if not, back to the drawing board

But on the plus side, I'll be a good test case for this type of repair.

Cheers,
Jim

[rkanaga]

Sorry, I should have read your previous posts!

Good to hear that snap ring failure does not automatically cause major internal damage though (of course the next one to fail might be worse)

When you had the transmission apart, was there an obvious mismatch between the snap ring and the groove in the upper transmission housing in which it sits? (my understanding is that the problem is that the groove is cut too wide in the transmission housing leading to flexing of the ring, stress and eventually failure.)

My gearbox is out at present having some other unrelated work done. The snap ring hasn't failed, and I was going to replace it anyway, but I wondered whether I could determine the chances of later snap ring failure by examining the transmission housing and either inspecting or better measuring the width of the ring and its corresponding groove?

I understand that only some of the gearboxes in the snap ring range fail as the drill used to cut the grooves went gradually out of tolerance as the production run proceded, and as the drill bits were replaced every so often during the production run it's impossible to know from your transmission serial number whether your individual gearbox is at risk, only that if the serial number is within the range that it MIGHT be at risk (also the risk various continuously depending both on driving style as well as on HOW out of alignment the drill was at the time your box was cut, which explains why the rings can fail as early a 2000 miles and as late as your 97000 miles). As mine hasn't failed (but it has only done 30k miles) I don't want to replace the transmission housing for a fault that might not actually be there!

thanks and regards

Robin

[jaytip]

I think an important point is being missed here guys.Yes replacing the ring will be ok(if there was no damage done to the 'box)BUT ONLY FOR X AMOUNT OF MILES.It will go again if the casing is not changed.
rkanaga,if you 'box falls into the snap ring range and its already out of the car i would advise biting the bullet and replace the casing.It's more likely to be when and not if your gearbox will fail if it is in snap ring range.Remember the only ones that would be ok are the first 'boxes to be machined after the drill has been replaced.Every other one will have a degree of play in the fitting and will eventually fail.
All of the above is just my opinion though :D

[mutley]

Hi Robin,

If you have the gearbox out already, on the rear of the casing there it a small inspection cover with a square drive socket. Take this off and you will see the snap ring (or circlip) sitting. I don't think you can tell from here about the grove, but if you then turn the box manually you'll be able to see the shaft turn and the ring holding in place, but I have to admit that the groove was quite a good fit in mine, so I think my snap ring failure was due to normal wear and tear for the age of my car, and I don't think it was very well looked after by previous owners.

As I said, this little cover will allow you to see it (and if you are thinking about removing the casing, you'll have to open this up to compress the ring so that you can lift it off the shaft. But another little hint, if you don't have to open it, I wouldn't recommend it, it's a bit tricky to put back together. As the old saying goes, "if it's not broken, don't fix it".

If it does fail on you, you'll certaily know about it, 1st becomes very difficult to get (lots of nasty grinding noises and you have to hold the gearstick in) and in second, your stick wobbles about. This won't necessarily cause a lot of damage, but grinding gears and bits of snap ring floating about inside can never be a good thing.

[mutley]

I think an important point is being missed here guys.Yes replacing the ring will be ok(if there was no damage done to the 'box)BUT ONLY FOR X AMOUNT OF MILES.It will go again if the casing is not changed.
rkanaga,if you 'box falls into the snap ring range and its already out of the car i would advise biting the bullet and replace the casing.It's more likely to be when and not if your gearbox will fail if it is in snap ring range.Remember the only ones that would be ok are the first 'boxes to be machined after the drill has been replaced.Every other one will have a degree of play in the fitting and will eventually fail.
All of the above is just my opinion though :D


Hi Again

Jaytip does make a fair point, but as I said in my other posts (scroll up a wee bit) I am fairly happy that this repair has worked, and I will be a good test case to see if and when it fails again. I mean my car has now done over 97k, so if there are cars in a similar rage of gearbox with a lot lower miles, I'm sure they can sleep easily knowing that Yes it may fail, but on the positive side it may be a long way away if at all.

Don't worry, if mine does go again soon, you all know about it as you'll hear my cursing and swearing for about a 4000 mile radius!!

[megahertz]

Does anyone know the exact serial number gearbox casing 'range'? correct me if wrong, but it only applies to gearboxes in 1992s no?! (sorry if mentioned above, just too lazy to read/scroll through...bleh! :P )

Cheers!

[rkanaga]

Which Cars Are Affected?

The snap ring failure is limited to transmission numbers J4A4-1003542 through J4A4-1005978. These transmission numbers are limited to 1991 and 1992 model year vehicles. You cannot determine whether a car is in the range for possible failure by VIN number, you MUST check the TRANSMISSION NUMBER because the transmissions were not installed in sequential order by VIN number. See Locating Engine and Transmission Numbers for instructions on locating the transmission number.

see http://www.nsxprime.com/FAQ/Troubleshooting/transmission.htm

thanks for the info Mutley!

Robin

[jaytip]

Hi Again

Jaytip does make a fair point, but as I said in my other posts (scroll up a wee bit) I am fairly happy that this repair has worked, and I will be a good test case to see if and when it fails again. I mean my car has now done over 97k, so if there are cars in a similar rage of gearbox with a lot lower miles, I'm sure they can sleep easily knowing that Yes it may fail, but on the positive side it may be a long way away if at all.

Don't worry, if mine does go again soon, you all know about it as you'll hear my cursing and swearing for about a 4000 mile radius!!
If i'm reading this correctly then i think you may be wrong.A car of your age with half the milage would have half the mechanical wear and tear,so it would not nessasarily fail on age(not milage) alone.If you have alook on prime there have been cases of cars with very low milage through to high milage failures.The truth is if a car is in snap ring range then NO-ONE knows when or if it will fail.

[mutley]

If i'm reading this correctly then i think you may be wrong.A car of your age with half the milage would have half the mechanical wear and tear,so it would not nessasarily fail on age(not milage) alone.If you have alook on prime there have been cases of cars with very low milage through to high milage failures.The truth is if a car is in snap ring range then NO-ONE knows when or if it will fail.

True very true, I suppose there is no guaranteed way of knowing if it will fail or not, so I'll go with it's a case of suck it and see. The options are:

1: Change the casing as a preventative measure or

2: Repair it when/if it fails or

3: Pray to the NSX God that you have one of the lucky bowes that will be fine.



Jim

[rkanaga]

If i'm reading this correctly then i think you may be wrong.A car of your age with half the milage would have half the mechanical wear and tear,so it would not nessasarily fail on age(not milage) alone.If you have alook on prime there have been cases of cars with very low milage through to high milage failures.The truth is if a car is in snap ring range then NO-ONE knows when or if it will fail.

I agree 100% with you

the chances of failure depend on

1) How much the groove in your box is out of spec (this varies continuously from not at all to a lot depending on where in the production run it was made. You cannot tell this from the serial number or whether it is an early or late box within the whole run as they changed the bits every so often)

2) How you drive the car as this will affect the stresses on the transmission

3) How many miles you have done


If your box went after X miles (of you driving so you know hwo it was used), and you replace the snap ring and drive it in a similar fashion then it is reasonable to expect it to last for a similar number of miles. But beyond that its a total lottery unfortunately!

regards

Robin

[rkanaga]

Finally decided to order a new upper transmission housing. $690 from Dali, and as my gearbox is out and in bits anyway (having a new clutch fitted and a 5th gear synchro problem sorted) so that I'm paying for the labour already it seems sensible to fork out a bit more to sort out the snap ring uncertainty once and for all!


I'll let you know what if feels like once it's back together guys. Thanks for all the advice.

[Accelera Comigo]

I've seen the circlip and groove photos on Prime, thanks for the pointer.

That's not a drilled hole, nor is it a problem of gradual wear of the tool during production, wear would make the groove smaller until the circlip didn't fit. Some casing grooves are oversize because they were machined wrong, the problem will possibly be randomly distributed around those gearboxes in production before the fix was made. It could be related to a specific operator or machine.

As an alternative to replacing the casing, can you do one of the following?:

Fit a thicker circlip
Machine the groove bigger and fit a thicker circlip
Machine it then fit two circlips
Weld up the groove, machine it then fit the right circlip
Insert the area then fit the correct circlip

AC

[mutley]

HI AC,

I see where you are coming from, but the problem there is that it isn't just the circlip in the casing, the circlip (or snap ring) also has to fit into a groove on the secondary shaft in the gearbox, as the clips job is to hold the shaft in place in the gear box.

So I suppose if you were going to fit a thicker clip and machine the case, you would also have to machine the groove on the secondary shaft also. So I suppose theoreticly that's all possible, but sounds like a hell of a lot of precision work.

Jim

[AR]

HI AC,

I see where you are coming from, but the problem there is that it isn't just the circlip in the casing, the circlip (or snap ring) also has to fit into a groove on the secondary shaft in the gearbox, as the clips job is to hold the shaft in place in the gear box.

So I suppose if you were going to fit a thicker clip and machine the case, you would also have to machine the groove on the secondary shaft also. So I suppose theoreticly that's all possible, but sounds like a hell of a lot of precision work.

Jim

It seems that unless one was a machinist, or new one that was good an cheap ( unlikely ) it will cost more than to replace the casing. But never understimate the efforts of a determined individual with a dremmel tool :).

Cheers,

AR

[mutley]

It seems that unless one was a machinist, or new one that was good an cheap ( unlikely ) it will cost more than to replace the casing. But never understimate the efforts of a determined individual with a dremmel tool :).

Cheers,

AR

Ary,

My thoughts exactly, to do all that machine work, unless you work in that field, it probably would cost more......i wouldn't fancy a DIY job at that

Jim

PS new snap ring still working perfectly

[AR]

PS new snap ring still working perfectly

Fingers crossed for you mate, perhaps as sugested, the changing of it now will last for as long as the last one did.

Cheers,

AR

[rkanaga]

Exactly. The cost in the repair is mainly for the labour in getting the box off and apart. The upper transmission casing is $690 + shipping from Dali (a lot more from Honda UK of course) so unless you are VERY skilled at metalwork (not me!) then I don't think it's worth the effort. I did think about it as my box is with a good gearbox repair specialist at present, but really the confidence of having a genuine replacement OEM casing that hasn't been modified is worth a few hundred dollars over a repaired one.

IMHO

[jaytip]

Exactly. The cost in the repair is mainly for the labour in getting the box off and apart. The upper transmission casing is $690 + shipping from Dali (a lot more from Honda UK of course) so unless you are VERY skilled at metalwork (not me!) then I don't think it's worth the effort. I did think about it as my box is with a good gearbox repair specialist at present, but really the confidence of having a genuine replacement OEM casing that hasn't been modified is worth a few hundred dollars over a repaired one.

IMHO
I think you have made the correct decision.You will have sooo much more peace of mind knowing that the correct OEM part is fitted to the car.

[Accelera Comigo]

HI AC,

I see where you are coming from, but the problem there is that it isn't just the circlip in the casing, the circlip (or snap ring) also has to fit into a groove on the secondary shaft in the gearbox, as the clips job is to hold the shaft in place in the gear box.

So I suppose if you were going to fit a thicker clip and machine the case, you would also have to machine the groove on the secondary shaft also. So I suppose theoreticly that's all possible, but sounds like a hell of a lot of precision work.

Jim

Jim

I reckon that circlip retains the outer race of a bearing in the casing, the shaft will fit the inner race of the bearing so will be nowhere near the circlip.

I see where you're all coming from, the cost of having to redo the job should anything go wrong outweighs the savings made on a case. However ...... you can have a lot of machining done for $690+shipping+vat+duty (£550?).

I don't want to persuade anyone without doing it myself, for example I don't know where in the box this is, vertical access to the site of the groove can give machinists a problem. If you know any local machinists it may be worth a discussion with them though.

AC

[mutley]

I'll stick with the gereral consensus, that if you want true peace of mind then change the case, Having had my gearbox apart twice, I don't recommend it, it's a bit fiddly getting it back together, but on the other hand, all I did was got rid of the old broken bits of circlip and put in a new one, so all it cost me was my own time, £3.50 for the clip and some beer for my mate that gave me a hand. Although having said that IF I'm unlucky and it goes again, I'll shell out for a new casing, but as I mentioned already, the new clip is doing it's job and I'm the guinea pig to see how long it lasts. If it does last (as I hope that it does) then I've saved myself a hell of a lot of cash. :)


Jim

[rkanaga]

The difference is that you have the skills and patience to do this job yourself. I think that just replacing the clip is fine under those circumstances. But I need to pay for 10 hours + of someones labour to do this so I really don't want to do this more than once!


regards


Robin

[mutley]

HI Robin,

I know what you mean, there are places that will sting you for labour charges.............. I'll do it for £200 hehehe

If you are going down the new casing route (which is probably the wisest route, I'm just a tight arsed Scotsman that likes a challenge!!!) at least you know that you won't have to worry about any future probs in that department.


Jim