Unfortunately this person is wrong and following his/her advice will render damage to your manual transmission.

a) check the owner's manual
b) call the dealership
c) check the FSM

 

I will stop by this weekend and ask for you all, I have a busy week so I can't until then.

The weather has been between 20-50 here like a damn see saw, but even at lower temps I can't hear much. The whine IS gone and the whistle seems to be 90% gone as well, however, it is still not silent for all intents and purposes. I don't know if all Gs have some inherent noise in the manuals, ie I don't know if I'm trying to hear for something and any little noise is now abnormal or if there is some degree of "normal" sound. I will try to check with some local guys at our meet in the near future to see if anyone notices anything different from their car or vice versa. Eugene do you have any insight on the matter, is some degree of noise normal for our transmissions?

The swap did remove the whine altogether however, it remains to be seen whether the whistling is truly gone, or whether in the future it will come back.

 

if i'm reading the service manual right, it says GL-4 75w-90 for transmission and GL-5 80w-90 for the diff. BG Gear oil says it's 75W-90 and usable for all GL-5 applications and GL-4 applications that match the viscosity.

so i could get enough of this stuff and use it in both the tranny and the diff? plus the additive if we think it's useful.

also, to everyone, does gear oil brand matter this much, or is weight really matters? in theory, if we think that the issue is that the oil is too thick when cold, wouldn't dropping down a to thinner oil when cold be where we'd want to go with this?

 

I think if you use a GL5 compatible oil in your transmission where GL4 is required, you may compromise the synchros. There is something special in the way that GL4 oils are formulated that make them safe for yellow metals, such as the type of metals that synchros are made of....

As for the brand, I think any high quality synthetic gear oil will do - for viscosity, 75w90 is just fine to use instead of 80w90.. it's just like using 0w30 oil where 5w30 is recommended... the 0w30 is just a better product and is better to use especially in cold temps.

 

^glad i've got my head around it alright. thanks.

went to the local autozone and found 75W-90 Royal Purple Gear oil thats explicitly approved for both for GL4 and GL5 applications. anyone had any experience there? if not, i'll probably pick up 2 quarts and do my diff this weekend.

unless someone thinks its a must, i think i'm going to skip out on the additive. i just don't know about adding chemicals to the equation designed for helping out with a clutch-type LSD when we don't have one.

 

Its funny we're all talking about fluid changes. I bought the car in mid october with no whine. Had the dealership do the 30k tranny service and once it got cold I started getting the whine. One thing I clearly remember was when they gave me my receipt, the "parts" section listed ATF as the fluid used. I pointed that out to the SA and he ran out to check with the tech. Came back and said it was a "clerical" error and that they used the proper fluid. COuld it really be they're putting the wrong fluid in our cars?

 

there wouldn't be a whine unless it was cold though. If you only got the car in oct it may have always made the noise n you just didn't know yet.

That said I think I'd have made them at least get the car back up and prove to you it wasn't ATF.

 

Hey guys, I just got back from the dealership where I took the G for a drive with the tech there.

We got on the road and accelerated to about 40mph and the noise started. As I gained speed to about 60, the noise changed pitch and started phasing in and out after about 30 seconds, but never going away completely. The tech confirmed that he heard it too and told me:

"It sounds like it's your primary gear; just the way it's wearing."

And then the had this really sad look on his face, I couldn't quite figure it out. He mentioned a few ideas he had that he would try such as switching to a different type of lubricant, etc, but ultimately I think the look on his face indicated that he might have to replace my transmission...

Only time will tell - I'll keep you guys updated.

 

Cool, good luck. Oh and try and figure out what they use from the factory for the trans lube. I'm still interested in knowing but can't get a clear answer.

 

new trans going in from the factory .. I guess it's a good thing, but I loved the way my old trans felt and shifted... I hope this one is just as good. Does anyone know if they put in rebuilt transmissions or new ones?

 

^I've never heard of a rebuilt part of any kind going in as a warranty fix. I can't see it happening.

I agree. Adding it doesn't seem to have any purpose.

 

I'm almost certain that it is a new part. You can always ask and make sure that it is. My new transmission is shifting smoother than my old one, I can say that.

 

I don't know this car well, but RX-8s do use at least partially rebuilt engines when they've got one in with blown apex seals from the factory.

that's just one instance though. i have no idea how widespread of a practice it is in the industry. i can't imagine there's anything in the warranty contract preventing them from using refurbed parts.

everyone who's getting them replaced says they're getting new ones. i wouldn't worry too much. of course, they may just be assuming they're new... [shrug]

 

The weather is getting warmer so I haven't had the urge to change my differential fluid. Anyone else have luck with BG differential fluid?

 

^ changing mine with Royal Purple 75W-90 this weekend. i'll let you all know when i do.

ALSO: Update from the guy i've been emailing back and forth with about the issue - Got a cold spell here so took the car in last night and had it sit at the dealer overnight. They did some work this morning and were able to replicate the howl. Their best guess after using the stethoscope is a failed output shaft seal. They have ordered the part and will have it in by early next week. I don't have any more details on whether that's the output shaft coming from the rear diff as I only got a voicemail from them early this afternoon. I'll attempt to get more info when i pick the car up. I'll also let you know if this solves the problem.