I had my '04 6mt sedan serviced (54k kms) recently and had the manual tranny fluid changed out for Pennzoil Synthetic. After consulting a local Infiniti dealer, my garage used 75W-90 GL-5. GL-5 was specified by the dealer.

The manual calls for GL-4, so does searches in Driver and elsewhere online. With this info I phoned the local dealer and was told the same as my garage, they use GL-5.

Should I be concerned with the fluid installed? Do I need to drain the GL-5 and put in some GL-4?

Any constructive advice is appreciated, thanks.

 

no need to worry, GL-5 is perfectly fine in the car. I've put 80-90 GL-5 with limited slip in 2 friends cars over 15k miles ago and it works great.
-GP-

 

There is a lot of conflicting information on this. From what I can gather not every GL5 is equal and the issue is compatibility with certain metals in the tranny. You might consider contacting the manufacturer of the product you are using to confirm compatibility with the G and application.

 

Synchros don't like GL-5 - it's too slippery and can cause crunchy shifts. Most of my experience is with BMW MT cars (E21 320i, E30 325iS, E34 535iM, E34 M5) and they don't work well with GL-5 due to the high-shear properties of that lube reducing the effectiveness of the synchros. GL-4 is best for MT applications, especially if the handbook specifies it. RedLine MTL works well as a synthetic replacement.

 

thanks for the info. since the fluid replacement i have noticed that the shifts are much more "notchy", and less smooth then before. this would support interalian's comment.
i am seriously considering draining the brand new $$$ fluid. i can see the synchros taking a beating after a few thousand kms the way it's shifting now.

 

^I had the same experience and drained mine. I replaced it with another synthetic GL5 with friction modifiers designed for MT's. Lucas oil. Works great.

 

hmm... maybe the specific GL-5 put in your car didnt have a limited slip additive in it (or friction modifier). Or maybe since i'm using 80-90 which is a little thicker, it doesnt have the same affect.
-GP-