Anyone using Mobile 1 Synthetic GearOil?

I have heard of one report, of it ruining a transmission in a hyundai tiburon.

GL-5 the rating of the Mobile 1 synthetic gear oil eats away at bronze and brass. Is any of that in our transmission?

What does eveyrone else use?

I hear GM Syncromesh is good.

 

The GL-5 oil contains to many anti-friction additives. The GL-5 is designed for differentials or hypoid geartrains. The GL-5 was designed for high impact geartrains. The resoning behind not using the GL-5 is that the anti-friction additives, creates too slick of a surface for the syncronizers to properly do there job. It requires more force to get the job done and increases the wear of the syncro. The GL-5's oil is not compatiable with yellow metals like Brass and Bronze, it will pit and eat into the surfaces causing failure of the components. The best route to go is with a natural oil and add in a quart of GM Syncromesh.

 

I can tell you if a trany ever failed and it had synthetic in it it probably wasn't the fluid that made it fail.

I have been runing Amsoil synthetic trany fluid in my 2001 Kia Spectra ever since I got it. After doing a total trany fluid change (not just droping the pan half fluid change) the trany is warm to the touch after driving instead of hot, it shifts better and my gas mileage increased about 1 to 2 miles per gallon. If it has done all this and reduced friction in the trany it also means your gaining a little more HP at the wheels.

How can a fluid (create too slick of a surface)? I don't buy that. Anything that reduces friction will in turn lengthen a parts life.

Amsoil has a warrenty if you use there product and there oil or what ever fluid you are using cause a failer, they pay for it 100%. You can't beat that kind of backing. Check out there site.

www.amsoil.com

 

In on of my conversations with Red, he had mentioned that his dealership had seen some tranny failures with synthetic gear oil. I don't remember the specifics behind it, only that me mentioned it.

 

Hyundai makes a "fill for life" type of gear oil. Will post part# when I get to work. Hyundai's own gear oil is pretty pricey.

 

Hey kolb... Its not that the gear oil is too slick that causes the failure, its that the additives in the synthetic gear oil eats away at brass and other yellow metals.

 

Most manufacturers of manual transmissions and transaxles recommend an 80W or 90W GL-4 lubricant. GL-5 gears oils which are required in hypoid differentials are not used in most synchromesh transmissions because the chemicals used to provide the extreme pressure protection can be corrosive to synchronizers, which are commonly made of brass or bronze. Typically, the use of a GL-5 lubricant in a synchromesh transmission will shorten the synchronizer life by one half. The extreme pressure requirements of spur gears and helical gears found in transmissions are not nearly as great as found in rear-wheel drive differentials. A GL-4 lubricant provides adequate protection for most manual transmissions, unless a unique design consideration requires the extra protection of a GL-5.

 

Sh!t, now I gotta change my tranny fluid again. That was such a PITA the first time too. What really pisses me off is how much better and smoother my transmission feels and has been shifting with the Mobil 1 synthetic over the Hyundai fluid, yet the synthetic is actually destroying my tranny. sad.gif frown

 

You should contact Amsoil and see what they have to say about there oil eating away at brass. I'm sure they have something that will work in your trany and not hurt it. Plus it will by synthetic so it'll still shift well and you'll get all the benifits of using a good synthetic.

 

Ok now is everyone looking in there manuals and actually seeing what kind of fluid goes in there trans!!

Unless there has been a change since 1997. You don't use GEAR OIL in your 5spd you use AUTOMATIC trans fluid!

silly sounding I know but it is true!
I use Mobil 1 synthetic ATF in my 5spd and have not had a problem from it!

There is nothing wrong with synthetics if you have them keep them and if you don't check it out they work great and save HP in the process!