Friction Modifier for Differentials.

Depends on which lubricant you're using. If it's the one that you should be using, it doesn't need it and if you use an additive with it, will only reduce it's designed specifications and qualities.

Don't do it!

FM's are used to smooth or eliminate clutch chattering.

For better winter shifting, use a synthetic oil.

What harm could it possibly do?

Have a look at http://www.findarticles.com/p/articles/mi_qa3828/is_200311/ai_n9320844
It may not be exactly what you're looking for but it's along that line.

quote:

Originally posted by prtdvl:
What harm could it possibly do?

Do some research on how manual tranny synchros work!

How about you do the research and post the results.

I'm not the one with the silly idea of adding a friction modifier(the kind that allows an LSD to slip more and slip smoothly) to a manual tranny that has synchros that require friction to work.

The thread should be titled, "lets disable the synchros by dosing the tranny with LSD FM's" and see if it will shift at all!

Yes, that's a good technical argument...pfff

Adding a friction modifier to you transmission will aggravate shifting problems. It makes it even harder for the synchros to "bite" and synchronise the gears. For cold weather shifting you will need to run a lighter grade oil. Downside is less gear tooth protection. The fix to this is to run a higher quality oil, specifically one that has low internal friction co-efficients and very high film strength, and packages designed to make synchros work while lubricating them.... As you can see the issue can quickly become very technically difficult.
So you ask: "What do you recommend?"
A: Poly-ol-ester based lubricants. I believe Redline Oil is the only company that makes this for automotive use. Very expensive but you won't be disappointed.

Regards,
Roger M

quote:

Originally posted by prtdvl:
What do you think about adding it to a manual trans. for better winter shifting?