Gear Shift Problem
05-16-2023, 04:36 PM
#16
RL Community Team
Rennlist Member
Rennlist Member
2009 C2S 189K miles
Mr Floyd has been spot on....
Do some Googling on GL4 and GL5.... one of the best I found is from Castrol here:
https://www.castrol.com/en_us/united...oil-specs.html
From their post: "Some manual-shift transmissions can use GL-5, but typically should not be used in synchromesh-type transmissions, as the EP additives can be corrosive to yellow metals found in those transmission types."
Mobilube PTX, which is specifically denoted in my owner's manual for use in our cars, is spec'd as a GL4.5 ... in the middle so to speak. As Mr Floyd noted the demands of a transmission are different than a differential.... manual transmissions can't be too slippery or the synchros won't synchronize and differentials can't be too watery or they won't be properly lubricated for the high loads.
From way back in 2015 when I posted about using PTX... https://rennlist.com/forums/997-foru...-gear-oil.html
Peace
Bruce in Philly (now Atlanta)
Mr Floyd has been spot on....
Do some Googling on GL4 and GL5.... one of the best I found is from Castrol here:
https://www.castrol.com/en_us/united...oil-specs.html
From their post: "Some manual-shift transmissions can use GL-5, but typically should not be used in synchromesh-type transmissions, as the EP additives can be corrosive to yellow metals found in those transmission types."
Mobilube PTX, which is specifically denoted in my owner's manual for use in our cars, is spec'd as a GL4.5 ... in the middle so to speak. As Mr Floyd noted the demands of a transmission are different than a differential.... manual transmissions can't be too slippery or the synchros won't synchronize and differentials can't be too watery or they won't be properly lubricated for the high loads.
From way back in 2015 when I posted about using PTX... https://rennlist.com/forums/997-foru...-gear-oil.html
Peace
Bruce in Philly (now Atlanta)
Last edited by Bruce In Philly; 05-16-2023 at 04:38 PM.
09-08-2023, 08:29 AM
#17
Just to tell you my experience / case: mine (MY 06 4S) does grind when cold in 4th and 5th and shifting over 3K rpm. Then when all is warmed up it is smooth like silk. Anyway: when I first bought the car one year ago, I notice this thing, I moved to a hi-end oil (ravenol VSG 75w90) and things were the same. After 400kms I decide to purchase the original OEM oil from Porshce and nothing has been improved. I think it even goes worst than Ravenol but nothing noticeable. I decided to add an ceramic Additive, XENUM VRX Gear, to try to solve the problem. Shifting was improved but grinding was still there when cold.
My mechanic suggested to change the clutch (60K miles) but I´m not sure on this. As this is a thing I will do for the next season I will see if this improves.
Regards.
My mechanic suggested to change the clutch (60K miles) but I´m not sure on this. As this is a thing I will do for the next season I will see if this improves.
Regards.
