Wanting to drain my tranny fluid. What is the recommended replacement?
A friend and I were talking about the recurring noise I have in my Pathfinder's manual trans. Basically, it's most noticeable when the trans is cold, or sometimes when shifting between 1st and 2nd or 2nd and 3rd. (sound kinda like that same problem some people have had with their Z's doesn't it?)
So, I did what I always do -- I did research.
Turns out that 99.9% of all "gear oil" sold in stores is API GL-5. Problem is, the factory spec for my Pathy is GL-4. Common logic would say, "Isn't GL-5 BETTER than GL-4?"
More research, please...
So I did some Google Group searches. (By far the best way to get instant info on the internet). Turns out that GL-5 includes some additives which are harsh on yellow metals (brass included) and can cause premature corrosion or breakage of bushings and synchros in your trans. Moral of the story, GL-4 is very different from GL-5, and if your spec calls for GL-4, you'd be well served to follow the manufacturer's advice. (Listen up, folks! The 350Z also calls for GL-4 gear oil!)
So all this had me wondering -- could it be that some 350Z owners have unknowingly replaced their gear oil with GL-5 and led to some premature problems? (I'm specifically thinking about folks who used Mobil 1 or other off-the-shelf synthetics -- most if not all of them are GL-5).
Just doing my part to look out for the troops -- if you've done an oil change on your MT, be sure to find out what type of oil was used, and if you have GL-5, GET IT OUT OF THERE!
Redline oils makes a GL-4 which I'll be looking for tomorrow for my Pathfinder. If any of you have done an oil swap on your trans, be sure to check what you used!
A quick follow-up after my recent junket in search of GL-4 gear oil:
1. None of the major oil manufacturers make GL-4 (by this, I mean Mobil, Valvoline, Quaker State, Pennzoil, etc.) All of them sell GL-5, which "exceeds the GL-4 standard". That's fine, but the part they fail to realize is that the additives which make it exceed the GL-4 spec is exactly what ruins your trans...
2. In rare instances, you can find GL-4 from local auto parts stores, but it's always a one-off brand that I wouldn't trust.
3. This whole experience would be a lot less painful if we could use GL-5 gear oil.
4. Redline's web site sucks. They need to include a database of local resellers sortable by ZIP code. The list they have stinks.
5. Summit Racing sells the entire suite of Redline products, AND they only charge $7.95 flat rate for shipping. Combine that with no tax, and you have a GREAT deal. I have a pile of stuff coming hopefully in time for the weekend.
Report to follow after the change of fluids...
In the meantime, a few more pieces of corroborating evidence supporting the theory that GL-5 will ruin Nissan trannys: