HEY! Grumpy, What's your opinion of synthetic motor oil and at what intervals do they recommend changing T56 6sp lube (normal driving) ? Thanks in advance
heat and dirt and moisture in the oil are the problems, changing oil and filters tends to prevent problems, modern oils are far better than what we had in the past, but Id suggest no more than 5K miles between oil and filter changes with mineral base oils and changing the oil filter on synthetics at 5000-miles and changing the oil an filter at 10K. remember oil must reach abiout 215F to burn off moisture so don,t try to keep the oil temp lower than that all the time I generally try to keep engine oil temps in the 190f-215 range and don,t worry about oil temps reaching 250F for brief periods
adding a few magnets to the oil pan helps trap metalic dust and crud btw.
on synthetic oils, the advantage is slightly better film strength , better high heat luberacation,and a noticably higher heat resistance to break down, most mineral base oils start to break down slowly at about 240F and bye 260F they start breaking down far faster, most synthetics easily operate up to 280F-290F without breaking down quickly
keep in mind modern oils are designed to trap and transport crud to the filter, but it takes a decent filter to make the system work as designed, (removing the crud from the oil flow)
almost all current oil is far better than what was available even 15 years ago!
http://people.msoe.edu/~yoderw/oilfilterstudy/oilfilterstudy.html#fram-ph8a
http://forum.grumpysperformance.com/viewtopic.php?f=54&t=120&p=150&hilit=magnet#p150
http://www.digitalcorvettes.com/forums/showthread.php?t=85963
quick story
I had, at the time, a MUNCIE M21 in one of my corvettes,(the 1968)
it worked ok but it always had a slight whine and shifts were a bit slugish, ,after I had the car about a week, I mentioned that to a buddy who was a pro nascar mechanic at the time, he ask me about the lube,I was using,Id just filled the trans with the chevy dealer recommended lube so I told him it was full and new,( I had no clue (back in 1971) synthetics were almost unheard of back then, ) he brought some over to the house amd we drained the old lube, replaced it with what he swore was what they used at his shop.......the differance was ASTOUNDING, the whine disappeared, the shifts smoothed out over the first few hours, I could hardly believe it was the same transmission. yes theres advantages, and yes Id recommend a good synthetic like MOBILE or AMSOIL
manual transmissions generally benefit from oil changes about every 60K
most problems are the result of not changing the filters frequently enought, once the filter medium becomes partly clogged the filter rapidly starts to bye-pass at least some percentage of the oil durring cold starts and rapid changes in rpm levels, most of the cleanable filters Ive examined have very limited surface areas so they would need to be cleaned very frequently.
the better throw aways have 400 sq inches of surface area, Ive never seen a single cleanable oil filter that states thier screens surface area but looking at them Id be amazed if it exceeded 220 sq inches
look closely at the design of the filters and youll see the differances
http://people.msoe.edu/~yoderw/oilfi...html#fram-ph8a
heat and dirt and moisture in the oil are the problems, changing oil and filters tends to prevent problems, modern oils are far better than what we had in the past, but Id suggest no more than 5K miles between oil and filter changes with mineral base oils and changing the oil filter on synthetics at 5000-miles and changing the oil an filter at 10K. remember oil must reach abiout 215F to burn off moisture so don,t try to keep the oil temp lower than that all the time I generally try to keep engine oil temps in the 190f-215 range and don,t worry about oil temps reaching 250F for brief periods
adding a few magnets to the oil pan helps trap metalic dust and crud btw.
on synthetic oils, the advantage is slightly better film strength , better high heat luberacation,and a noticably higher heat resistance to break down, most mineral base oils start to break down slowly at about 240F and bye 260F they start breaking down far faster, most synthetics easily operate up to 280F-290F without breaking down quickly
keep in mind modern oils are designed to trap and transport crud to the filter, but it takes a decent filter to make the system work as designed, (removing the crud from the oil flow)
almost all current oil is far better than what was available even 15 years ago!
http://people.msoe.edu/~yoderw/oilfilterstudy/oilfilterstudy.html#fram-ph8a
http://forum.grumpysperformance.com/viewtopic.php?f=54&t=120&p=150&hilit=magnet#p150
http://www.digitalcorvettes.com/forums/showthread.php?t=85963
quick story
I had, at the time, a MUNCIE M21 in one of my corvettes,(the 1968)
it worked ok but it always had a slight whine and shifts were a bit slugish, ,after I had the car about a week, I mentioned that to a buddy who was a pro nascar mechanic at the time, he ask me about the lube,I was using,Id just filled the trans with the chevy dealer recommended lube so I told him it was full and new,( I had no clue (back in 1971) synthetics were almost unheard of back then, ) he brought some over to the house amd we drained the old lube, replaced it with what he swore was what they used at his shop.......the differance was ASTOUNDING, the whine disappeared, the shifts smoothed out over the first few hours, I could hardly believe it was the same transmission. yes theres advantages, and yes Id recommend a good synthetic like MOBILE or AMSOIL
manual transmissions generally benefit from oil changes about every 60K
most problems are the result of not changing the filters frequently enought, once the filter medium becomes partly clogged the filter rapidly starts to bye-pass at least some percentage of the oil durring cold starts and rapid changes in rpm levels, most of the cleanable filters Ive examined have very limited surface areas so they would need to be cleaned very frequently.
the better throw aways have 400 sq inches of surface area, Ive never seen a single cleanable oil filter that states thier screens surface area but looking at them Id be amazed if it exceeded 220 sq inches
look closely at the design of the filters and youll see the differances
http://people.msoe.edu/~yoderw/oilfi...html#fram-ph8a