Gear oil smell after transmission fuid change.

[GatorDun!]

As the title states, I can smell gear (transmission) oil ever since I changed the fluid.
I used Redline 75W-90. I was under the car today looking for leaks, but saw none. I'm perplexed.
There was no smell before the fluid change.
Any ideas?

[bcrdukes]

It's possible there could be some that dribbled somewhere and is being burned off by the heat.

[GatorDun!]

It's been a few hundred miles since I changed the fluid. If that were the case, it would have burned off by now. I'm not seeing smoke. It just smells like hot gear oil.

[pilot4fn]

The oil level is very important to be right. On 5-speed, the level should be 11mm below the fill plug lower edge.
If the oil is overfilled, it is fairly common that some transmission oil seeps thru the oil seal at the transmission input shaft to the clutch bellhousing. On the bellhousing is a lot of opportunities to collect the small amount of oil before it leaks down to be visible.

[997_986]

You can fill until it drips out of the hole, no need for "11mm" below. Your oil might get too hot, but no need to corelate with your change. Is it the right specification, you should find an GL-4... oil that is equivalent to 999 917 546 00. I changed it to a fully synthetic 75W-90 GL-4/5 too and it works perfectly

[pilot4fn]

Originally Posted by 997_986

You can fill until it drips out of the hole, no need for "11mm" below. Your oil might get too hot, but no need to corelate with your change. Is it the right specification, you should find an GL-4... oil that is equivalent to 999 917 546 00. I changed it to a fully synthetic 75W-90 GL-4/5 too and it works perfectly

You're right on 6-speed transmission, but on 5-speed it is on Porsche service manual as well as here at Pelican specified to fill only to 11mm below the fill hole.
Of course everybody can do to own car as pleases. I'll stick with Porsche Service manual instructions

https://www.pelicanparts.com/techarticles/Boxster_Tech/38-TRANS-Manual_Fluid/38-TRANS-Manual_Fluid.htm

[GatorDun!]

Originally Posted by 997_986

You can fill until it drips out of the hole, no need for "11mm" below. Your oil might get too hot, but no need to corelate with your change. Is it the right specification, you should find an GL-4... oil that is equivalent to 999 917 546 00. I changed it to a fully synthetic 75W-90 GL-4/5 too and it works perfectly

I used Redline 75W-90 which is a fully synthetic GL-5.

[Bill Ladd]

Just for the hell of it, check for a split cv joint boot.

[GatorDun!]

Originally Posted by Bill Ladd

Just for the hell of it, check for a split cv joint boot.

Ha! I noticed a split boot yesterday when I was replacing the engine mount!

[Bill Ladd]

Originally Posted by GatorDun!

Ha! I noticed a split boot yesterday when I was replacing the engine mount!

I’d be willing to bet that’s where your smell is coming from.

[GatorDun!]

Originally Posted by Bill Ladd

I’d be willing to bet that’s where your smell is coming from.

You might be right.
Strangely, I didn't smell it until I changed the transmission fluid.
Maybe fresh oil is more fragrant! 😁

[Bill Ladd]

Originally Posted by GatorDun!

You might be right.
Strangely, I didn't smell it until I changed the transmission fluid.
Maybe fresh oil is more fragrant! 😁

Might be coincidental.

I had just done the rear driver side outer axle bearing and soon began smelling what I thought was burning grease. Smelled like it was coming from the rear passenger side. I assumed it was that bearing going out, so I changed that side too. Made no difference in the smell so I crawled back up under the car and gave you a good look around and found the inner boot was torn and slinging a bit of grease.