I had 140 wt GL-4 in my Maxima transmission, and as you can imagine it was a nightmare to shift in cold weather. I flushed it out with 3 quarts of 5W30 motor oil and a quart of Synchromesh MTF, and then filled it with 5 quarts of Synchromesh.

Initial thought after filling with Synchromesh is that it's an improvement. I don't drop as many RMP when I let the clutch out in neutral ( it did drop 200 RPM when cold with the 140w GL-4). The car just has a lighter feel when driving, the shifting is smoother and effortless, and the car does not feel as sluggish.

I will post later with updates as to long term performance.

 

I've had sncromesh in my max since May. I could not find GL4 locally and refused to pay to have it shipped. Something about shipping in fluid just doesn't sit well with me. I have had no problems at all with it. I swapped it out when I swapped tranys, so I can't really say if I saw an improvement. Everything works fine so I am happy with it.

Thanks for posting up your experience, I could have used this thread in May when I was trying to find other fluids besides GL4

 

Synchromesh is not the correct fluid for your transmission. Not only is it the wrong viscosity, but it also doesn't contain the proper additives required to protect your transmission and ensure proper operation. Recommend you use a GL-4 of the proper viscosity which the manufacturer specifies.

 

Still working great. This is the fluid that Valvoline recommends.

Real tribologists at bitog have also said it is a very good option. This is yellow metal safe, which is all GL4 means.

Sent from my XT1060 using Maxima

 

So Valvoline has a statement on their website that synchromesh is a great substitute for GL4? I'd like to see that.

Please send that link, too. I get the impression that GL4 is becoming more and more rare so I would like to see what other compatible options are out there to keep my 5MT going.

 

Valvoline? I thought we were talking about Pennzoil Synchromesh?

Pennzoil does not advertise this fluid as a direct replacement for a 75/80/90 GL-4. It's not labeled as such and their Tech Support will not recommend it...

Some of the parts stores chains such as O'reilly's, pep-boys, etc list Valvoline Synchromesh and the item description states:

" Valvoline Synchromesh Manual Transmission Fluid is a high performance manual transmission lubricant designed to meet the extreme demands of passenger car manual transmission gearbox applications in certain General Motors and Chrysler vehicles including GM part numbers 12345349, 12377916 and 12345577 as well as Chrysler part number 4874464. Valvoline Synchromesh Manual Transmission Fluid is not intended for all manual transaxles or transmissions."

I don't know if there's a difference in product lines, if it's still a current product, or if it's available to the consumer market, but I've discovered that Valvoline does have a "Professional Series" MTF and the data sheet does state that it is safe for use in applications requiring GL-4. But there's still a viscosity issue that has to be considered...as we know, GL-4 is a service classification, not viscosity, and using a fluid of the correct viscosity is also important.

As with the "Professional Series MTF", I don't know if this is a current product or not, but I did see where Valvoline lists a Max-Life GL-4 75w-90. GL-4's of suitable viscosities are also available from a number of oil manufacturers.

I think you will find from my posts that I am typically very conservative in my recommendations and I do not recommend products that do not meet Nissan's requirements. That's just me.

Sychromesh has been around for a long time and the smart people at Nissan who designed the transmission specified GL-4 of a certain viscosity for a reason. I don't try to second-guess them.

I wish you continued success with Synchromesh...