c5 Trans oil

[dave]

I'm a new C5 owner so I'm still learning. Having had a C3 and C4 I realize the C5 is a different animal. Todays question is why the manual trans. has ATF rather than gear oil?

[Rich Z]

If I had to take a wild guess, I would say because the ATF is thinner and likely has cooling properties that thicker gear oil can't provide via a transmission cooler.

BTW, I put in Royal Purple and it made a noticeable difference in smoothing out the shifting.

[gmjunkie]

Originally Posted by dave

I'm a new C5 owner so I'm still learning. Having had a C3 and C4 I realize the C5 is a different animal. Todays question is why the manual trans. has ATF rather than gear oil?

Better lubrication properties and flow for closer tolerances in gear cut,more use of caged needle bearings,roller bearings,(More bearing surface than ball bearings,= less ware,longer bearing life and ability to take the Stress and Torque of guys like RichZ that just have to make them Meaner and Meaner!!) friction surfaces on syncro cones are made from a material similar of friction plate surfaces of Automatic transmissions,I've never had to many Muncie's go 100,000+ miles without at least a input shaft bearing and a couple syncros!!

Originally Posted by Rich Z

If I had to take a wild guess, I would say because the ATF is thinner and likely has cooling properties that thicker gear oil can't provide via a transmission cooler.

BTW, I put in Royal Purple and it made a noticeable difference in smoothing out the shifting.

I'd say your right on running cooler too!!
I've got Royal Purple in All my 6 sp's too,Slick sh*t ain't it,I can drop the hammer and power shift mine 2-3-4 and make'er jump like a frog in every gear like I could my 68 427 Tri-Power Roadster!!

[dave]

Thanks for the reply. The answer makes sense. I've heard a lot said about Royal Purple. Being a long time fan of Amsoil, do most consider Royal Purple a better choice than Amsoil atf for 6sp?

[Bradzvette]

........one thing to watch, older model C5 transmissions have paper blockers, the sythenetic oil will destroy the blockers. I think 2000 was the year it changed. Someone may know for sure the exact year it changed.

Just an FYI

[Melsy]

I changed both my tranny and rear end oil with AmsOil and have been please on my '03 Z06.

[shakedown067]

Originally Posted by Brad@TheCorvetteShow

........one thing to watch, older model C5 transmissions have paper blockers, the sythenetic oil will destroy the blockers. I think 2000 was the year it changed. Someone may know for sure the exact year it changed.

Just an FYI

I've heard that about the C4's 4l60e as well. Never heard why, but that they tend to have issues with non GM synthetic oil.

[dave]

What are paper blockers???