I got my fluid put in, and I like it a lot. The shifting seems to be getting smoother, but I now have this weird smell in the car every once and a while. I am not sure what it is. Does anyone have this problem? Maybe its something else and it just happened to start showing up when I had my transmission and differential fluid changed.

Did you change it yourself or have someone else do it? The fill and drain are on the opposite side from the cat so there shouldn't have been any spills or dripping. Trans and dif fluid are pretty strong smelling. It wouldn't take much residue to have a noticeable smell especially after things heat up. Get underneath and wipe down around the fill plug. There's a ledge right under it that can be holding some fluid.

Did you change it yourself or have someone else do it? The fill and drain are on the opposite side from the cat so there shouldn't have been any spills or dripping. Trans and dif fluid are pretty strong smelling. It wouldn't take much residue to have a noticeable smell especially after things heat up. Get underneath and wipe down around the fill plug. There's a ledge right under it that can be holding some fluid.

Thats it. I watched them do it because I wanted to learn how. They did spill a little, but I didn't think it would be that strong, especially inside the car.

i have this problem too, do i just need to clean around there???

sorry if this is kidna old.

The main thread for this is here: Gear oil smell (http://www.rx8club.com/showthread.php?t=108672). Everyone have the same problem. I'd like to see what Mazda's fix will be when everyone hit 60k and change their transmission fluid. There are going to be some irate people when they get their car back and it smells like a giant fart inside.

my diff and transmission fluid has been changed twice now in my car's 40k miles. I have never had any gear oil smell.

Consider yourself lucky then. You can usually guesstimate how widespread a problem is by the frequency of people piling into a thread with "me too" type of response. In this case, there are tons of them. I think as more people go for their first transmission fluid change, the true extent of the problem will become more apparent. This is not an isolated problem.

me too... lol. yes it is a problem many seem to be having.

I noticed NO change in 'shift feel' going from OEM to RP @ 27K miles on the odo.

I noticed NO change in 'shift feel' going from OEM to RP @ 27K miles on the odo.

I changed at around the same interval and there is definitely a difference. Not night and day mind you, but the RP feels thicker and cushion the shift engagement better. You can only feel it when you're shifting gently and let the gears fall into place. It did nothing to solve my 2nd gear notchiness when cold.

I don't think transmission fluid change is all that necessary, but if you're swapping out the differential fluid, might as well do the MT too. And the rear diff definitely can use a change every 20k.

just replaced my tranny and diff fluid w/ RP maxgear 75w90 @ 60k miles. i had redline previously and i think the purple stuff is much better. it shifts slicker than a stick of butter that has been placed on top of the rx8's oem catalytic converter after many consecutive high speed runs without time to cool down =P

ive had the gear oil smell pop up a few times since ive swapped in the new fluids......but it smells kinda good i like it :)

I like the RP Maxgear, I used the Amsoil stuff before and it SUCKED. The tranny was insanely notchy and sometimes wouldn't engage 1st and 2nd, I'll never use their tranny/diff/engine oils again. Put in the RP and it shifted smoothly again like stock, no weird smells either. Make sure your fill/drain plugs aren't loose and it's not dripping and burning off.

just replaced my tranny and diff fluid w/ RP maxgear 75w90 @ 60k miles. i had redline previously and i think the purple stuff is much better. it shifts slicker than a stick of butter that has been placed on top of the rx8's oem catalytic converter after many consecutive high speed runs without time to cool down =P

ive had the gear oil smell pop up a few times since ive swapped in the new fluids......but it smells kinda good i like it :)

you like the smell of the oil? uh oh... haha

you like the smell of the oil? uh oh... haha

i also used to eat playdoh and sniff paint when i was younger. :ylsuper:

[QUOTE=djmano]just replaced my tranny and diff fluid w/ RP maxgear 75w90 @ 60k miles.

QUOTE]



so you can use the same material for both the tranny and differential??

My tranny's fluid has been changed 3 times already. No smell.

Im planning to do change no.4

crazy rx-8 driver,

a board member emailed royal purple and the representative said that we should use RP maxgear 75w90 in both trans and diff. he said he runs the same in his rx-7 fd3s!

so you can use the same material for both the tranny and differential??

yes.

crazy rx-8 driver,

a board member emailed royal purple and the representative said that we should use RP maxgear 75w90 in both trans and diff. he said he runs the same in his rx-7 fd3s!

Cuz thats what Mazda recommends

but Im thinking I might try 75w140 next time. for rear diff, Its going to rob some power but gives me better protection .... thinking ...

crazy rx-8 driver,

a board member emailed royal purple and the representative said that we should use RP maxgear 75w90 in both trans and diff. he said he runs the same in his rx-7 fd3s!


sweet deal! thank you so much you guys! off to the store i go! :wiggle:

The stuff is good, I tried Amsoil 75W90 and it was HORRIBLE. Immediately switched to RP and it shifts smooth just like stock. Also just put the same stuff in my Miata for both the tranny and diff.

I will be changing my tranny and diff with RP in a few weeks as well.. Just got the crush washers ordered in.. just need to get my jackstands back from my friends place.. should be a good thing from what i hear

holy damn, went to NAPA today and they had their RP up for 15 bucks per qt !!!! is that a rip off or what??

what should i expect to pay here?

Thats a RIP OFF !

Get it online, like rpmoil.com

http://www.rpmoil.com/index.php?main_page=index&cPath=7&zenid=45abcb8a090c2a1aeae73232d2454816

Not the cheapest, 10 bux each quart, 8.99 flat shipping. but their service is fast and very friendly.

how many quarts do i need all together for changing tranny and differential fluid?

how many quarts do i need all together for changing tranny and differential fluid?OMFG !!!!

SEARCH SEARCH AND SEARCH !

My 05, 28K miles running 9K rpm without any problems. I do it all the time

Synthetic Oil Rules ! :P :Peace:
edit: here you go: http://www.rx8club.com/showthread.php?t=35115
oh yeah, I heard that even Mugatu's dog searches? :cussing:
Laters!
Edgardo

how many quarts do i need all together for changing tranny and differential fluid?

just under 4. I think it's 1.8 and 1.6

holy damn, went to NAPA today and they had their RP up for 15 bucks per qt !!!! is that a rip off or what??

what should i expect to pay here?
I paid $10 per quart at the local Pep-Boys. No shipping that way either.

Yep, same here Royal Purple Maxgear for $9.99 at Pep Boys + tax.

Here's my total cost for doing the change including the tools (and thanks to all for DIY infos!):

RP fluids: 4 x $9.99 = $40
Crush washers (from dealership): 4 x $1.20 = $2.40
23mm socket: $4
15/16 socket: $4
socket wrench: $5
Flotool Tubing (to fill diff. fluid): $3
Vinyl Tubing 6ft. (to fill trans. fluid fed thru engine compartment): $4
Torque Wrench (big long clicker type... the rear diff. drain plug was seized and a PITA with a typical socket wrench... I needed more leverage!): $18
Jack-stands: 4 x $7.50 = $30
Stock car jack: Comes with your car!
Oil Pan: $3
Shop paper towels: $2
DIY Labor: 1-2 hours @ $0.00

Total DIY cost: approx $115.00 or approx $50 if you already have some tools.

I didn't have very many tools for this specific job so I went out and bought most of them. The most difficult part of this job was actually re-filling the trans. fluid! It's kinda tricky so you must improvise. I feel really good knowing that I probably saved a bundle doing this myself vs. going to the dealership.

I don't work on cars much at all, but was able to do this myself (with the help of info. found here). You guys are awesome! Many thanks for sharing your knowledge. I'm so happy with the results and my 8 now runs like new @ exactly 45K miles! (I also changed my oil while the car was up on 4 jack-stands)... even dropped in a Green Air Filter while I was at it.

addendum: Oh yeah, and no stinky smell in the cockpit... yet!

Yep, same here Royal Purple Maxgear for $9.99 at Pep Boys + tax.

Here's my total cost for doing the change including the tools (and thanks to all for DIY infos!):

RP fluids: 4 x $9.99 = $40
Crush washers (from dealership): 4 x $1.20 = $2.40
23mm socket: $4
15/16 socket: $4
socket wrench: $5
Flotool Tubing (to fill diff. fluid): $3
Vinyl Tubing 6ft. (to fill trans. fluid fed thru engine compartment): $4
Torque Wrench (big long clicker type... the rear diff. drain plug was seized and a PITA with a typical socket wrench... I needed more leverage!): $18
Jack-stands: 4 x $7.50 = $30
Stock car jack: Comes with your car!
Oil Pan: $3
Shop paper towels: $2
DIY Labor: 1-2 hours @ $0.00

Total DIY cost: approx $115.00 or approx $50 if you already have some tools.

I didn't have very many tools for this specific job so I went out and bought most of them. The most difficult part of this job was actually re-filling the trans. fluid! It's kinda tricky so you must improvise. I feel really good knowing that I probably saved a bundle doing this myself vs. going to the dealership.

I don't work on cars much at all, but was able to do this myself (with the help of info. found here). You guys are awesome! Many thanks for sharing your knowledge. I'm so happy with the results and my 8 now runs like new @ exactly 45K miles! (I also changed my oil while the car was up on 4 jack-stands)... even dropped in a Green Air Filter while I was at it.

addendum: Oh yeah, and no stinky smell in the cockpit... yet!

nice job.. good on you.

beers :beer:

just under 4. I think it's 1.8 and 1.6

thanks! cant wait till i get my tranny and differential fluid changed this sunday and hopefully ill feel a difference... ill let you guys know

you are not alone, the first service i did i replaced with RP for the transmission and diff. the smell was quite noticable in the car for 2 months.. even after that.. still some faint smell.. and i discovered there was a hole in the first rubber boot cover after the leather cover.... suspecting mechanic poked a farking hole when they put the tranns back up and the gear stick poked it.. when they change the rear diff bcoz of some noise... and this was done at mazda

HOWEVER i dont think is just bcoz the hole that is causing the smell to come in, from another thread of changing short shift kit some part of the shifter actually touches the trans oil too, so i am suspecting over filling would cause the oil to spill out a bit in to the area underneath the first rubber boot, because i discovered little bit of trans oil in the first rubber boot..

thanks swoope!

Okay, 130 miles since the tranny fluid change... happy to report that there's no "smell" yet. Perhaps it's being overpowered by the pina-colada car scent i have in my AC vents? Anyhow, I don't notice it so it's all good.

However, something I have noticed is that going into 5th gear @ 4000 rpm or higher seems to be a little notchy, and sometimes a slight griding sound occurs. That's never happened before, but it seems consistent now and I have to shift really slowly when going to 5th. At lower rpms it shifts very smoothly.. and when car is in idle, shifting is very smooth. Anyone have ideas or know why this might be happening?

changed the tranny and differential fluid to royal purple for about a week now and the shifting seems a little notchier than before and dont really understand why... any idea from anyone?

Just make sure you didnt overfill.

and your tranny is functional.

I just changed both my tranny and diff with RP maxgear 75w90 @ 15.5K miles. I love the feel of the shifting now. The tranny plug didnt have much on the magnet, but the diff was caked.

I also bought a case of 5w20, and changed that and put in a Mobil1 oil filter.

No smell.

Just make sure you didnt overfill.

and your tranny is functional.

my tranny was replaced by dealer about 7k miles ago and was quite smooth before i changed out the old fluid. the reason why i changed it out was because i thought it would be better. anyways i thought underfill would cause such problem? so how would you know if it is just right? thanks

One question for all you experts. Is there any danger in overfilling the tranny or diff. I may have overfilled the tranny by .3q, it took about 2.1q. The rear also took about 2q. What would the symptoms of a overfilled tranny and diff be? Are you suppose to wait till the dribbling stops before you plug it? Thanks.

One question for all you experts. Is there any danger in overfilling the tranny or diff. I may have overfilled the tranny by .3q, it took about 2.1q. The rear also took about 2q. What would the symptoms of a overfilled tranny and diff be? Are you suppose to wait till the dribbling stops before you plug it? Thanks.

Anyone have an answer?

I've had my auto transmission fluid changed and there is no smell.

Just wanted to add that I have had RP Max gear in diff and gearbox, then changed to Redline lightweight shockproof.

My RP MaxGear lasted me 4 track sessions and 9 months (I shouldnt have but I did :p:) before it started to feel yuck. It was filthy when it came out but that was my fault for leaving it to long. Changed to RL a month ago and felt better but 1 month later and 2 track sessions and its horrid again.

I am going back to MaxGear.

As for overfilling, I cant see any damage being done but, i believe there are breater holes in the diff and so possibly overfilling the would caue the smells people are getting.

Just wanted to add that I have had RP Max gear in diff and gearbox, then changed to Redline lightweight shockproof.

My RP MaxGear lasted me 4 track sessions and 9 months (I shouldnt have but I did :p:) before it started to feel yuck. It was filthy when it came out but that was my fault for leaving it to long. Changed to RL a month ago and felt better but 1 month later and 2 track sessions and its horrid again.

I am going back to MaxGear.

As for overfilling, I cant see any damage being done but, i believe there are breater holes in the diff and so possibly overfilling the would caue the smells people are getting.
RL lightweight shock proof is really a 70W140 oil and probably not the best choice for a tranny. Better for rear ends. In a tranny you would be better off using Super Lightweight which is a 75W90 GL5 gear oil, but with some trannies it may be too slippery and you may crunch syncros a little.

RL lightweight shock proof is really a 70W140 oil and probably not the best choice for a tranny. Better for rear ends. In a tranny you would be better off using Super Lightweight which is a 75W90 GL5 gear oil, but with some trannies it may be too slippery and you may crunch syncros a little.
Understood but I wouldnt have thought that would cause it to deteriorate faster?

Understood but I wouldnt have thought that would cause it to deteriorate faster?

Could be one of two things:

Probably the opposite actually happened. It normally takes about 50- 100 miles for the Redline gear oils to become meshed in with all the gears and force out the old lubes, when that happened you probably didn't have enough friction to keep the syncros from clashing.

Or

The weight when warm was too thick and exceeding 220F, so you were getting break down of the gear oil (almost all GL-5 gear oils start breaking down around that point).

In the old days of brass bushings and syncro gears (like the FC gear boxes), 220F and mobil1 or Valvoline synth gear oil and the lube starts breaking down due to the acid build up.

a test of the gear oil would show which one was the case.

BUT!!!!!! why the redline and not the maxgear? Excuse my realy uneducated knowledge here, but in theory as you said the redline is 80W140 and so should have better viscosity at higher temps. I would have thought it was better able to deal with the higher temps than the maxgear. I had never thought of testing the oil afterwards.

I have a friend who is an auto-transmission tech so will ask him if he is able to.

anyone know what the stock Tranny/Rear Diff lubricant is for the rx-8? I put Royal Purple in about 1K miles ago, and so far have experienced grinding downshift to 2nd & 5th gear, and notchy upshift into 5th above 4k rpm. I'm thinking about going back to stock fluids but not sure what Mazda uses.

The stock factory transmission oil is a straight 90 weight.

The stock factory transmission oil is a straight 90 weight.

thanks LionZoo... is there a particular brand they use?

thanks LionZoo... is there a particular brand they use?

No idea. As it is, it's difficult to find a straight 90 regardless of brand.

BUT!!!!!! why the redline and not the maxgear? Excuse my realy uneducated knowledge here, but in theory as you said the redline is 80W140 and so should have better viscosity at higher temps. I would have thought it was better able to deal with the higher temps than the maxgear. I had never thought of testing the oil afterwards.

I have a friend who is an auto-transmission tech so will ask him if he is able to.

There are quite a few Redline gear oils. The one he brought and was using was in the Shockproof line.

Shockproof oils have different flow and shear characteristics than even conventional Redline gear oils.

A unique lubricant containing a suspension of solid microscopic particles as an extreme pressure agent--unique solid dispersion which cushions gear teeth to help prevent tooth breakage and allows the use of lower viscosities. The viscosity characteristics allow the lubricant to resist throwoff and provide a film thickness greater than an SAE 250 grade, with the same low fluid friction as with our 80W140. Recommended for heavily-loaded racing differentials and transmissions, Off Road racing and problem gearboxes. Offers a "best of both worlds" balance of relatively low drag and the utmost in protection.

And from red line on the oil he was using (light weight shock proof):
A unique gear oil designed to lubricate racing transmissions and transaxles which see serious loads (not recommended for most syncro-type transmissions). It has excellent low-temperature flow which allows easier shifting when cold. May be used to obtain maximum power transfer in racing differentials which do not see high temperatures. Similar to a 75W140 gear oil, but with the lower internal friction of an SAE 30 motor oil.

Used in most road-racing differentials with moderate power and dogring racing transaxles.

He should have used Heavy Duty Shock proof, if he felt the need for shock proof:
A unique lubricant containing a suspension of solid microscopic particles as an extreme pressure agent--unique solid dispersion which cushions gear teeth to help prevent tooth breakage and allows the use of lower viscosities. Recommended for heavily-loaded racing differentials and transmissions, Off Road racing and problem gearboxes. The viscosity characteristics allow the lubricant to resist throwoff and provide a film thickness similar to a 75W250 grade, while providing the same low fluid friction as an SAE 75W90.

I actually normally use Redline MT-90 for most manual tranny applications requiring a 90W:
Popular in Nissan, Toyota and Mazda manual transmissions and transaxles as well as other selected applications, this is a 75W90 GL-4 Gear Oil that’s slightly heavier than MTL. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting.

I use MTL or a 50/50 mix of MTL and MT-90.
I've had that combo in every Mazda I've owned.

I was using MTL when #2 shattered, it's only a 75W80 fluid

IMO the problem is the trans oil getting too hot for the viscosity, so my recommendation is heavier fluids. It may come down to how hard you push it as the exhaust can transmit a lot of additional heat to the transmission.

Yeah, heat is the issue.
Modern trannies don't have much in the way of "impact" forces against friction components, so the oil is mostly for cooling and radial lubrication.
Thinner oils dissipate heat a little more quickly than thicker oils do, but you may be giving up some lubricity for that advantage.

maybe need to measure the trans oil temp---someone hook it up!
OD