BTW, where did you get your amsoil oil? And how long have you been using the amsoil oil? Perhaps your smooth shifting impression of the amsoil oil was due to the synchromesh not being completely flushed out of the tranny.

After reading about all these oil threads, no real conclusive information can be gathered out of it. I don't want to leave any doubt or "what ifs" in my head and have decided to just use OEM fluids for everything when I hit 15k miles.

The thing I noticed about my notchy shifting is that it only happens when I shift fast. If I hold the clutch down for a second and then put it into gear, it's always smooth. This tells me that the clutch restrictor is the cause of the notchy shifting as it causes a slight delay in reaching full clutch disengagement. I'm going to yank the clutch restrictor out one of these days and I'll see what difference it makes. I already have a SS clutch line and poly shifter base bushings installed.

 

So, if I'm following this thread correctly:

MT-90 is a straight replacement for stock gearbox oil, and a thinner mix improves shifting feel (for those who didn't like the original)?
(The first improvement I'd want to make would be to kill the clutch restrictor, before tweaking the fluids.)

Redline 75W90 Synth is too thin for the TC? (Were the "blown" TCs being pushed when cold?) Shockproof (light or heavy) is an adequate replacement (unless you have to take your lawyer when talking to your dealer)?

I'm confused, now. According to the web site (redlineoil.com), Shockproof light is like a "75W190", and heavy has the "protection" of "75W250" with the flow of a "75W90". Shockproof is apparently made for (non-synchro) bash boxes, and they stress the good cold shifting characteristics. Why would this be any better cold than the 75W90 Synth in the TC? Isn't the key to not push the TC until it warms up, rather than the fluid?

Redline 75W90 Synth or Mo1 75W90 okay for the rear diff?

I had already picked up MT-90 and 75W90 Synth for the EVO, but I haven't changed the boxes yet. (Mo1 10W30 in the mill). No biggie if I can't use the 75W90 in the EVO, as it works fine in the Alfa (75W90NS in the GB, 75W90 in the Rdiff, Agip in the engine).

I don't imagine we're likely to get a consensus. But can we get a majority? (Maybe a poll???)

PS: After doing the Alfa GB/RDiff, for the next gear oil change, I'm going MOP-3. (That's some nasty fumes coming off the gear oil -- especially the old stuff.)

 

See, the breakages happen during drag racing launches. In drag racing, the transfer case sits cold since the cars don't move around much during race time. Cars just sit in the pits waiting to stage. So your oil is at 75W when you launch.

 

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