RacePro Engineering

Gentlemen,

From those of you who are running the C4 ZF 6-speed box for ROAD RACING, what are you using for gear oil? We are much more concerned with gear wear protection and cooling than with long-lasting properties.

First-hand experience only, please. Thanks,
Ed

RacePro Engineering

Rusty Guns,

Which viscosity range of the RedLine are you running?

Ed

Sidney004

Amsoil MTF user here:http://www.amsoil.com/storefront/mtf.aspx
100+ track hours(though not all of it on MTF), 77K miles, original clutch, shifts smooth. These are really tough gearboxes, of all the things that can go break racing a C4 Corvette, I think the ZF 6 speed should be the least of your concerns. Also, I have never heard or read about the ZF being prone to overheating. The black tag version is supposed to be beefier than the blue tag.

RacePro Engineering

Sidney,

Thanks again for a very learned opinion, and the web site link! We have heard good things about the Amsoil product, and it would be a big bonus to NOT have to plumb a tranny cooler.

We were devout users of Redline synthetic until we prepped a 911 several years ago, and discovered that gearbox thrived on Swepco, and essentially "rejected" everything else. Since then we realize that different box configurations "prefer" different lubricant formulations.

Are you personally using the base 5w-30 viscosity range for track/racing? That seems extremely light weight to me. We appreciate your advice.

Ed

66IISS

We've been using the redline lightweight shockproof oil and have been very happy with it. It seems to have quited down the gear chatter at idle as well.

Sidney004

I use MTF, exactly the link shown,even meets the GM spec.

STEVEN13

Hi Ed,

I used the RedLine for many years with no problems. Currently using the Amsoil-local Dealer close to my house. I am pretty sure that the Amsoil for the ZF has only been available for the past 5 years +/-. If I am wrong I am sure someone will correct me.

I have also been using the RedLine power steering fluid (since 2001) with an underdriven crank pulley-no issues.

Steve

RacePro Engineering

66IISS and Steve,

I am doing this from memory, but the Redline Shockproof is available in 75w-90 (which we use in Hewlands), and (I believe) 80w-100 that is used by F-Atlantics with Webster gears.

So, 66IISS, when you write "light weight", are you referring to the 75W-90 viscosity, or something even lighter, like one would use in a motorcycle?

My primary reason for asking is that the spec for Sidney's Amsoil MTF appears to be 5w-30, and that is a long way from the 75W-90 we are accustomed to. Indeed, if the ZF box likes a very light oil, we'll be happy to give it exactly what it likes best. Just want to be sure.

Thank you for your continued clarification!
Ed

PS: Steve, thanks for the additional tip about the PS fluid. We know these units to be problematic when placed under high stress.

Sidney004

Ed: The Amsoil 5W-30 is SAE engine oil rated viscosity whereas the 75W-90 is SAE Gear oil rated; the 75W-90 is definitely thicker but it is not as dramatic as it seems because the rating scales are not symmetrical.

http://www.bobistheoilguy.com/cms/in...d=48&Itemid=55

Pumba

There is a forum sponsor who builds manual transmissions and has built them for 1,200 rwhp standing mile cars. The fluid that they found worked best was Royal Purple Synchromax. In the case of these high horsepower standing mile vehicles, using other than the Synchromax, the trans gear set would burn up in one run down the mile.

RacePro Engineering

Sidney,

I appreciate the clarification - you are a fund of information. Thanks for the great chart!


Pumba,

There's our HEAT, isn't it? No, we will not sport 1200 HP, RW or otherwise!

I find it just facinating how so many racing specialties have their own, minutely specific, requirements! Hardware (and lubricants) that are more than sufficient (even over-kill) for one type of event, are found sadly lacking in another, similar form of racing.

Ed

RacePro Engineering

So, Gentlemen, just to be absolutely certain -

The Amsoil Manual Synchromesh Transmission Fluid, being a lubricant for (primarily) gears, does NOT use the Gear Oil viscosity grading system? Instead, it uses the SAE Engine Oil grading system?

As such, when the Amsoil product is marked "5w-30", its true viscosity is roughly equivalent to a product using the Gear Oil grading system, and marked, say, "70w-85".

Are all these statements correct?

Thanks for a final double-check. It's giving me a headache!
Ed

lbs90ZR

Bill at this website is helpfull if you have more questions. http://www.zfdoc.com/techinfo.htm I've been using BMW 10w60 with no troubles, but it's only seen about 15 track days.