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C5 six-speeds: improved shifting and durability

Hib Halverson

Technical Writer for Internet & Print Media
Jan 10, 2001
CenCoast CA
71 04 12 19
Forum members-
I've been monitoring an informal, subjective, field test of synthetic alternatives for the lubricant used in the Borg-Warner and Tremec, T56 six-speeds as used in the 97-01s.

To date, from those doing the testing, I've heard very positive results in improving shift feel and reducing effort once the lubricant in those transmissions is switched from the factory-fill, Dexron III automatic transmission fluid to Red Line D4 synthetic automatic transmission fluid. The improvement is so significant that the speed with which one can shift may improve enough to rival the speed gained with aftermarket "short-throw" shifters but *without* their increased effort or "notchyness".

One report in particular crossed my desk yesterday. It was a testimonial from a guy who owns a Z06 with about 2000 miles on it. He recently changed the trans. lube to Red Line D4. He claims to have noticed an improvement in shift feel as soon as he backed the car out of the garage and drove less than a mile. Doubting himself maybe a bit, he turned the car over to his wife, who's not a technical person and was unaware of the fluid change. She noticed enough of a difference in shifting to comment upon the improvement later that day.

I've read or heard a number of other anecdotal accounts from people who've switched to D4 ATF and claim similar results.

Another feature of Red Line's D4 ATF is a synthetic's ability to reduce oil temperatures during severe duty operation, such as autocross or road race competition. We've not been actually tested for temperature numbers but I know from being exposed to the use of Red Line lubricants in other manual transmissions, such as the ZF S6-40s used in 89-96s, during severe duty, there is a noticeable decrease in transmission temperature and an increase in durability when a synthetic lubricant is used.

By adding a transmission over-temperature warning light on U.S. Z06s and on all C5s sold for export, along with offering, through the GM Performance Parts program, a motorsports transmission cooler kit for C5s, GM is demonstrating it knows C5 manual transmissions run excessively high operating temperatures during aggressive driving. Red Line's synthetic transmission lubricants can reduce transmission temperatures and increase reliability and durability of C5 manuals used that way.

The recommended Red Line lubricant for street-driven C5s that might also see occasional motorsports use is D4 ATF. The recommended Red Line lubricant for C5s that are see regular street/track use in hot weather or are race-only is MTL. I know, once I buy a C5, it's six speed will have one of those two lubes in it soon after I buy it.

Anyone wanting more information on Red Line manual transmission lubes ought to look at http://www.redlineoil.com or call Red Line at 800-624-7958.
Welcome Wagon

Hib Halverson ~ ~Welcome to the CorvetteActionCenter~ ~

Wow that is one heck of a 1st post. Thanks for sharing the information with all of us :cool:

Please take some time and take a look at all the information our Administrator, Rob, has assembled here in the Corvette Action Center website. The Saloon is open 24/7 but not always people there. Work tends to get in the way, But stop by for a few

Good to have you onboard :) Enjoy


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