Just an update, as expected since they didn't replace the rubber boot the new leather shift boot is slowly picking up the gear oil smell as well. I might be getting used to it though since it's no longer as apparent to me, or maybe it's fading, or maybe it hasn't fully permeated yet like before. I suppose putting in a new rubber boot along with a new leather boot will fix the problem, at least for the time being, but I'm going to wait awhile longer and see if the smell gets stronger as at this level I doubt the dealer techs will pick it up and so I would have to pay out of my own pocket for a warranty item that should be free.

 

While I was swapping the motor, I re-filled with MTL.
After everything was back together, I pressure washed the drive train.

No more smell.

 

I'm thinking about going to a MT90/MTL mix next time I change my gear oil.

 

How about an update on this type of fluid please, Team? You mentioned "significantly less" smell. So there is still some odor with the Shockproof? If the smell gets worse when the warm weather rolls in I'll probably swap.

I had the 30k service done by my mech ~6 weeks ago & switched to Redline. It smelled strongly for 2 weeks then went away. But, like CRH, it is definitely on & off since then, with the worst times being after running for a while.

Taking it to the mech tomorrow for a once over - though now that I've found it's fairly common I guess it'll be more of a leak check appointment just to satisfy my curiosity and make sure there's no mess on my stick.

 

I flushed my transmission (and differential) oil again and replaced the rubber boots as well as the leather boot. I went back to Redline MT90 for the tranny and 75W90 for the diff. The smell is of course gone from the boot area, but I'm currently getting it through the air vents when the car is warmed up. That smell is subsiding though and I expect it to be fully gone in a couple weeks just like the first time I changed to Redline.

The MT90 itself though, I'm not sure about. I filled about 1.75 quarts of that stuff in; considering capacity is 1.8 and there's probably still some oil in there I don't feel like I've underfilled. However, the shift quality is slightly crunchy at times when the tranny is cold so I have to be careful. This doesn't seem like how it normally is as my past two times flushing my tranny, cold shifting was fine until a few thousand miles later. I'll pay more attention to it, but for the time being I'm going to chalk it down to my synchros starting to wear out.

The MT90 seems to use the synchros in a different way from the Royal Purple though. Royal Purple offered less crunchy shifts, but more synchro whine. The Redline is crunchier, but synchro whine is less. I might try BG next time I flush, unless Team wants to chime in with how he's doing with the Shockproof.

 

I may have mentioned this in another thread on clutches or transmissions:

I noticed that when the car is cold if I pump the brakes before using the clutch the shifts are much easier till it warms up.

at first I thought it might be placebo but I don't think it is.

 

BG Synchro Shift worked wonders for my car. I was having trouble with a grinding shift into 2nd and 4th. It got so bad that virtually anything over 4k was a grind. It's completely gone with the BG in. Very smooth shifting in all gears now. Gear whine is more noticable, but there isn't a hint of grind. I'll take whine over grind any day

 

I hate you. Now I'll be tempted to get it.

 

The clutch and brakes use the same fluid reservoir...

 

I changed the trans and diff gear oil last spring with about 10K on the car. Refilled with Royal Purple. I had the gear oil smell the first few times I drove the car afterwards. The smell went away though before I got around to pulling the shift boot.

I'm not complety happy with the smoothness of the shift. Has anyone used any additive with the Royal Purple that they would reccomend?

 

That's probably just dribble on the transmission and differential casing burning off. My boots were actually contaminated to the point where they smelled like gear oil.

I can't help you with the smoothness issue. The factory fill has probably been the best for me; I want to know what they use from the factory.

 

anyone else noticed that you only get the gear oil smell when you drive with the windows down ?

 

^ I can smell it all the time. Sometimes it's so bad I have to open the windows even if it's single digit temps.

 

Mine was from the boot. Right now it's coming through the vents, but I didn't wipe my transmission and differential casing after changing this weekend so I'm thinking that's what it currently is.

 

yes,

mine is gone now, but it was only there with the windows down.

beers

 

I tried all the known (by me) gear lubes in my trans---ended up with 50% of 75/90W and 50% 75/140W RP Max gear(NOT the syncro shift stuff). The slightly heavier weight ( I have over 50K on my car) is what worked for me.
OSCD

 

Interesting combo. I'm beginning to suspect this gearbox might like a thicker cold viscosity than what a synthetic 75W90 gives. Factory oil is straight 90 weight.

 

My next transmission flush and fill is going to be with Amsoil Severe Gear 75w110.

I already received it. They had recommended it as an option.

The rear diff is going to be using the Amsoil Severe Gear 75w90.

 

As apposed to the front one seriously, why such a light weight in the rear?

 

Well I have a new to me 2004 that apparantly had the tranny flushed at 30k. It has 32k on it now. Its at Mazda for a display problem and the smell. I doubt they will be able to do anything about it if none of you guys have found a solution.

Should I put a different fluid in the car or try and check the shift boots or clean under the car with degreaser? At least you guys have assured me that it isnt engine oil.

 

Is the smell subsiding or staying the same?

 

i know i have seen this issue elsewhere on the forums however i don't recall ever seeing a reason / solution so what about oil / somewhat burning oil smell coming from the drivers side rear wheel? i notice it when i pull in my garage at night. anybody know the cause of that?

 

taek up the plastic trim that includes the cupholders... wipe away oil. only smells once it accumulates. i threw an air freshner in there and put eveything back. the smell helps.. but the air freshner can asord the oil .. also helpin

 

The smell is strong. Even in the morning after it has been sitting all night. The wife is complaining becuase of the smell and the fact that it didnt smell when we test drove it. The dealer had it in to repair the heater and they changed the spark plugs, coil and battery because of rough idle. The smell started when I picked it up.

They checked it yesterday and no leaks, smell cause unknown. They are doing the ac amplifier service recall and replacing the radio cage becuase the display scrambles when I tap the radio or hit a bump (unrelated to smell).

If they dont fix it, I will pull up the center console and look for spills.

Does the car smell that way if they overfilled the oil or trans?

 

Sniff around your leather shift boot. Does it smell like gear oil? A method I find is useful is rubbing your fingers on the leather shift boot where it's recessed as the oil will be first to collect there. If your fingers smell like gear oil after rubbing the boot, your leather boot is contaminated, which means the rubber boots covering the transmission is probably contaminated as well. In that case, both boots will need to be replaced, which should be warranty work, but is a bit of a fight to do it.

By the way, if the dealership changed the transmission oil, they could've possibly overfilled it. The spec calls for 1.8 quarts of oil in the transmission. Generally, the way to tell if the transmission is filled to capacity is to fill until oil starts dribbling out of the fill hole. However, we've found that even when there's fully 2 quarts of oil in the transmission, there is no dribble. Your dealership could've made that mistake and just filled until it started dribbling.