Cold weather / Stubborn tranny

Blanco 300Z · Dec 9th, 2005, 12:24 PM

hey guys, I've been workin on my car and changed all the fluids and filters after i purchased it a couple of months ago. I noticed it is a little stubborn going into gear on a cold morning (old car no biggy) but this morning it was FRIDGID! like 23 deg or something. the tranny was whining for a bit (almost like until it got lubricated) I currrently have all synthetic fluids throughout the entire car and in the tranny I have SYN GL5 75 90 gear oil. is there any additive that the transmission needs or just go to a lighter fluid like GL4 for the colder season ??

**Spongerider** · Dec 9th, 2005, 02:02 PM

Quote:

Originally Posted by Blanco 300Z

hey guys, I've been workin on my car and changed all the fluids and filters after i purchased it a couple of months ago. I noticed it is a little stubborn going into gear on a cold morning (old car no biggy) but this morning it was FRIDGID! like 23 deg or something. the tranny was whining for a bit (almost like until it got lubricated) I currrently have all synthetic fluids throughout the entire car and in the tranny I have SYN GL5 75 90 gear oil. is there any additive that the transmission needs or just go to a lighter fluid like GL4 for the colder season ??

What tranny do you have?

Auto = ATF
Manual = 75w-90

You don't need to put a additive in it.

Blanco 300Z · Dec 10th, 2005, 09:21 PM

Quote:

Originally Posted by Spongerider

What tranny do you have?

Auto = ATF
Manual = 75w-90

You don't need to put a additive in it.

5 spd btw, does the speedo have a cable or electronic? cuz i think speedo is off a lil too but has been like that since i had it

**Spongerider** · Dec 12th, 2005, 02:53 AM

Quote:

Originally Posted by Blanco 300Z

5 spd btw, does the speedo have a cable or electronic? cuz i think speedo is off a lil too but has been like that since i had it

It's a cable, there is a sensor that probably needs to be replaced. By what you wrote, you have the wrong oil in your tranny?

Blanco 300Z · Dec 12th, 2005, 10:40 PM

Quote:

Originally Posted by Spongerider

It's a cable, there is a sensor that probably needs to be replaced. By what you wrote, you have the wrong oil in your tranny?

sensor for calibration or something?? my speedo is off about 10 percent or so. but for all i know the tranny could be out of something else (the fun of buying a used car) I know the engine was replaced. anyway.... only whined on me one time. I normally let the car wark up a few minutes but for some stupid reason I was late for work and got in a hurry and fired beasty up and took off on the coldest morning I ever had in texas(which sucks cuz i moved to get out of cold shit) but so far it seems to be an isolated incident. was just thinkin of maybe goin with something a little thinner for winter. anyway with a little luck (being that I have the 75 90 already) won't happen again

Bror Jace · Dec 13th, 2005, 09:18 PM

Owner’s manual calls for 75W-90 in the tranny? Not all 75W-90s are the same, even those labelled “synthetic.” Probably the most common choice is Red Line Oil MT-90 which is a polyol ester synthetic GL-4 75W-90. Not a bad choice at all.

Don’t forget that GL-4/GL-5 is a rating for additive packages and has nothing to do with weight/viscosity. Generally, the higher the GL number, the greater the protection against wear … except that many GL-5 oils contained sulfur-based anti-wear or EP (Extreme Pressure) additives and are corrosive to soft metals such as copper (brass, bronze, etc …) found in many syncronized transmissions. Take a wiff, the smell of sulfur will be pretty obvious. These gear oils are mainly used in differentials in large solid axles featuring massive iron/steel parts.

You will see a few oils which are dual-rated: GL-4 and GL-5. This means they are safe (corrosion-wise) for GL-4 applications but have the robust anti-wear protection which passes the GL-5 tests. The best of both worlds.

Once in a while, you will see GL-6 … but it isn’t used much anymore and is considered obsolescent. I think I’ve only seen it on Synergen Syngear II.

Weight & GL rating together are the two most important pieces of information you need about a gear oil. One other is the coefficient of friction. Is the oil intended for use in syncronized/syncromesh gearboxes? Some trannies are pickier than others about this. The syncros need some friction in order to cleanly and crisply engage each other. A lubricant which is too slippery in a transmission can make for balky/graunchy shifting and actually accelerate wear.

So, what do I recommend? Specialty Formulations MTL-R which is a (genuine) synthetic 75W-90 rated for both GL-4 and GL-5 and has a coefficient of friction tailored for syncromesh trannies.

http://www.specialtyformulations.com/MTL-R.htm

My SpecV’s 6-speed calls for a 75W-85 so I use Specialty Formulations MTL-P, one step lighter than MTL-R. Great stuff!

If someone lived in Canada or some other extremely cold region, they might use MTL-P instead of MTL-R … but Texas? Even in the winter, I think you’d be fine with the MTL-R. It has a pour point of -42F.

It can get down to -25F here in upstate NY. My tranny isn’t ‘great’ at those temps, but the car is drivable and as long as I’m extra gentle shifting for the first mile or two, I don’t get crunching or grinding.