ATF Slightly Overfilled -- Will This Create ATF Smell

[PeterMazda5]

I recently replaced the ATF in my '08 5, using the technique one of this forum's members suggested -- pull off one of the hoses from the tranny cooler, attach clear hose that runs to bucket, and cycle the old fluid out and new ATF in until the fluid runs clear. I also replaced the filter, which included in its kit a gasket for the pan (OEM was simply some sort of sealant / gasket-maker). Having done all of this, I now have a small ATF smell that's sometimes stronger than at other times.

Specific to the gasket, the ATF filter kit indicated a layer of some specific type of grease should be applied before mating the gasket to the pan and tranny. I didn't have any such grease on hand and had to get the car done quickly, so I assembled everything without the grease. Would not applying this grease to the ATF pan gasket possibly cause a slow, imperceptable leak?

I don't see any big leaks at the pan, drain plug or hoses, but I do know that I SLIGHTLY overfilled the fluid. I've heard there's an ATF overflow hose that releases any overflowing fluid near the firewall. If the ATF is filled beyond spec, will it flow out through this overflow hose?

I'm hopeful overfull ATF is my my problem -- simply corrected if so by extracting some of the excess fluid. If that ISN'T the source of the leak, my only other thought would be the ATF pan gasket, and the only fix to that is to drop the pan and re-seal it correctly. I REALLY don't want to do that if I don't have to.

Thoughts?

Thanks, all. This is my first forum post, so be gentle with me!

Cheers.

--Peter
Woodstock, GA

 

[rodslinger]

I get the same odor sometimes and this is what I found on mine.

There is a 1/8" rubber hose that runs from a vent nipple on the top of the transmission housing to the transmission dipstick tube. It seems on mine after doing a drain/fill that when refilling the fluid, there may have been a trace amount of fluid run down this vent line also. Normally not an issue as it should be sealed. However I found that the hose wasn't perfectly sealed to the vent nipple and allowed some trace fluid to leak out on top of the transmission housing. Not enough to drip on the ground but it was enough to be able to smell it when the heat was on.

I imagine it is possible that if overfilled, excess fluid or the fluid vapors may be escaping out of the same location if no longer sealed properly.

And thanks for the reminder. I need to check it again....

 

[PeterMazda5]

Thanks -- I'll check that out.

I see you're in Smyrna, Rodslinger. We're in Woodstock. Do you do a lot of your own work on your 5? We just bought our '08 Grand Touring in July with 71k miles on it. Love it, but beyond this problem I created for myself, I think it's time for shocks and, at a minimum, sway bar bushings, as well as perhaps control arm bushings. Also went to the dual-tone horn setup -- a vast improvement over the OEM "meep-meep" one.

--Peter

 

[PeterMazda5]

Update. I think there was a small leak around the transmission's fluid pan gasket. I removed the pan, cleaned everything off, and I then applied black RTV to both sides of the gasket. We'll see, but I sure HOPE that fixed the problem. Might I add that I REALLY dislike the smell of ATF?

--Peter

 

[phunky.buddha]

ATF sure is stinky. I'm glad you figured out something that could have caused the leak!

 

[Silentnoise713]

Update. I think there was a small leak around the transmission's fluid pan gasket. I removed the pan, cleaned everything off, and I then applied black RTV to both sides of the gasket. We'll see, but I sure HOPE that fixed the problem. Might I add that I REALLY dislike the smell of ATF?

--Peter

Glad to hear the problem may be fixed! But might it also be due to overfilling since you have to drain and refill the ATF?

Could you share what gasket you used? Also, did you clean off the old compound to ensure a smooth surface (super important as any irregularities on the surface area would cause problems) and did you check (and recheck) your toque?

 

[PeterMazda5]

Silentnoise713, it turns out that I had only SLIGHTLY overfilled. I decided to drain the fluid because I believed the gasket was the problem -- I hadn't used grease on it as prescribed.

I did, indeed, clean off all the original OEM sealant compound and make sure the surfaces were clean ad smooth.

As for the gasket itself, it came as part of the transmission filter kit that I bought at Advance Auto Parts. It's the only kit they carry for the Mazda5.

--Peter

Glad to hear the problem may be fixed! But might it also be due to overfilling since you have to drain and refill the ATF?

Could you share what gasket you used? Also, did you clean off the old compound to ensure a smooth surface (super important as any irregularities on the surface area would cause problems) and did you check (and recheck) your toque?

 

[markuszoom5]

I am glad you were able to fix it, as I want to do a pan drop eventually at around 60-70k. I read that sometimes you can open Pandora's box with a pan drop and that's why the dealer won't even touch it. They only do flushes. I hope if I keep doing regular full flush I won't need a pan drop.

 

[Silentnoise713]

Silentnoise713, it turns out that I had only SLIGHTLY overfilled. I decided to drain the fluid because I believed the gasket was the problem -- I hadn't used grease on it as prescribed.

I did, indeed, clean off all the original OEM sealant compound and make sure the surfaces were clean ad smooth.

As for the gasket itself, it came as part of the transmission filter kit that I bought at Advance Auto Parts. It's the only kit they carry for the Mazda5.

--Peter

That’s interesting. By “grease”, do you mean sealant? What grease (sealant) did you use? I’d like to see what the instruction says. Mz5 kit was not an option for me at the time so I gambled on a Focus kit (same trans pan). I also got it from Advance Auto and it was the Duralast Kit -the gasket felt nice and thick IMO. Is this the same brand/kit that you used for the Mz5? Kit only came with the gasket and filter in the box, no instruction (not that I recall?). I don’t think the trans pan would endure high enough pressure to warrant additional sealant (assume quality gasket) but I suppose it does not hurt either. I would question if you really “need” it. Assuming you got a decent gasket, I wonder if torque distribution might be a culprit –there are lot bolts and should go over all of them a 2nd time with a torque wrench. Anyhow, a fix is a fix! The auto sure is much happier with new blood in her!

Btw, what ATF did you use? Be sure to report back after 20-30K miles and update us if it gets passing color. I just past 17 K on Amsoil and it has, and still is, fantastic!