Best diff/trans oil?
12-17-2014, 11:33 AM
#31
Race Car
My understanding is that it's actually hard to get a good oil for our transaxles (or any transaxle). The lubrication requirements of the ring and pinion (high-force / high-shear) are at odds with the lubrication requirements of the gear cluster bearings and the synchros (really blocker rings).
What is often overlooked is GL4/GL5 specification. GL4 is for transmissions, and is fully compatible with yellow metals (i.e. your bronze synchros). GL5, OTOH, is for hypoid gears (offset ring and pinion, where severe sliding and rolling friction occurs), and contains Extreme Pressure (EP) additives. Some of the EP additives will attack yellow metals. Newer ones will not, but not every oil out there uses newer ones.
I would recommend looking for a gear oil that is both GL4 and GL5 compliant. I think one of the Motuls is, but I don't recall. The Millers oils with nanotechnology are (CFS 75w90 NT is what our cars need).
Another problem to which Van alluded but not specifically is LS additive. LS additive is very slick, and designed to let the clutches disengage smoothly. ON a track, the oil is hot enough where it isn't an issue. But on the street, it is questionable. Problem with LS additive is that it can prevent the synchros from slowing down quickly enough. Both Guards and OS Giken recommend avoiding LS additive on the track. This is what I was getting at above - a guy may need the LS additive to prevent chattering in parking lot maneuvers, or on the street. But if he tracks his car, the LS additive may be tricky with the synchros.
12-17-2014, 12:11 PM
#32
Burning Brakes
Van that was a great video to explain how the transmission works. Thanks!
I haven't seen anyone talk about it, but when I first asked about this years ago the Redline Lightweight ShockProof gear oil, was recommend to me. I've been using it for street and hard, but not frequent, track use. Shifting is a little stiff when well below freezing (close to 0 F). There's been no chatter despite NOT adding FM (friction modifier) for LS.
I haven't seen anyone talk about it, but when I first asked about this years ago the Redline Lightweight ShockProof gear oil, was recommend to me. I've been using it for street and hard, but not frequent, track use. Shifting is a little stiff when well below freezing (close to 0 F). There's been no chatter despite NOT adding FM (friction modifier) for LS.
12-17-2014, 12:19 PM
#33
Burning Brakes
I just looked at Redline's web page on the shockproof oils and they now have the following statement that wasn't there before:
"Avoid use with pumps, coolers, and filters as unique medium and affinity for metal can cause clogging"
I have a cooler on mine and my understanding is if you have a cooler there is a pump for it, too. I guess I shouldn't run this anymore.
"Avoid use with pumps, coolers, and filters as unique medium and affinity for metal can cause clogging"
I have a cooler on mine and my understanding is if you have a cooler there is a pump for it, too. I guess I shouldn't run this anymore.