ZR-1 Net Registry Forums - View Single Post - Any of the recommended transmission fluids red?

Hib Halverson · 02-23-2019

Someone put ATF in that transmission. Not good.

It's absolutely not Red Line Heavy Shockproof. The stuff in the bucket is too thin and RLHS is not transparent. You would not see RLHS in a transmission, anyway. I know Marc suggests it for the S6-40, but during the late 90s, I was involved with Red Line helping their Chief Chemist, Roy Howell, test the Shockproof line for street use in the S6-40 and other applications. After testing, we decided Heavy Shockproof is a poor choice for helical-gear manual transmissions factory-filled with ATF or 5W30 engine oil. We settled on Light Shockproof for that.

Red Line MTL also, is not red.

When I had Barney I used Red Line Light Shockproof in the ZF S6-40. It worked very well for the 15 years I used it. I would change it about every three years.

I noted improved shift feel and a slight decrease in gear rattle.

02-23-2019	#13
Hib Halverson Join Date: Jun 2005 Location: CenCoast California Posts: 898	Re: Any of the recommended transmission fluids red? Someone put ATF in that transmission. Not good. It's absolutely not Red Line Heavy Shockproof. The stuff in the bucket is too thin and RLHS is not transparent. You would not see RLHS in a transmission, anyway. I know Marc suggests it for the S6-40, but during the late 90s, I was involved with Red Line helping their Chief Chemist, Roy Howell, test the Shockproof line for street use in the S6-40 and other applications. After testing, we decided Heavy Shockproof is a poor choice for helical-gear manual transmissions factory-filled with ATF or 5W30 engine oil. We settled on Light Shockproof for that. Red Line MTL also, is not red. When I had Barney I used Red Line Light Shockproof in the ZF S6-40. It worked very well for the 15 years I used it. I would change it about every three years. I noted improved shift feel and a slight decrease in gear rattle. __________________ Hib Halverson Technical Writer former owner 95 VIN 0140 current owner 19 VIN 1878 Last edited by Hib Halverson; 02-23-2019 at 03:04 PM.