I just purchased a 03 Infiniti G35 6mt with 120k miles. It was a one owner vehicle who took very good care of the car and almost all maintenance was done at either Nissan or Infiniti with receipts. But not one showed a trans service and now has 120k miles and I would like to replace the fluid. I've heard the horror stories about changing fluids this late in game is not good and have killed trannys but I'm skeptical on that one. I was planning one using OEM ATF but can you experts enlighten me please.
120k miles never had manual tranny fluid changed
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The horror stories you hear only apply to automatic transmissions. You can change manual transmission fluid at any mileage and it will not harm anything.
And even with automatic transmissions you can change fluid at any time. It's a common myth that changing trans fluid at high mileage causes failure, but it's only a common misconception and nothing else IMO.
And even with automatic transmissions you can change fluid at any time. It's a common myth that changing trans fluid at high mileage causes failure, but it's only a common misconception and nothing else IMO.
If you have a manual transmission, I believe it requires GL-4 75w-90 gear oil, not ATF.
I'd probably use Red Line MT-90 or Amsoil Manual Transmission & Transaxle Gear Lube 75W-90.
Most of the concern about fluid changes in older transmissions is for automatics. I wouldn't worry about it.
Do the fluid in the rear diff too.
I'd probably use Red Line MT-90 or Amsoil Manual Transmission & Transaxle Gear Lube 75W-90.
Most of the concern about fluid changes in older transmissions is for automatics. I wouldn't worry about it.
Do the fluid in the rear diff too.
Yup. I believe the ATF change causing failure myth comes from unmaintained vehicles.......When the tranny starts acting up, the owner finally gets the fluid changed......And the tranny fails, anyway.
It was already in failure mode. The last ditch attempt just did not save it.
As stated above, no harm will occur from changing a manual tranny's fluid. It can only help....
It was already in failure mode. The last ditch attempt just did not save it.
As stated above, no harm will occur from changing a manual tranny's fluid. It can only help....
Manual transmissions don't get near as hot as automatics. Many of them never require a fluid change at all. Although there's really no such thing as "lifetime ATF" for an automatic transmission, it is OK to do this for a manual in many cases.
Changing the fluid anyway will not hurt your tranny at all.
Even in an automatic, you can still change it as long as it isn't already acting up (if it is, then ATF change will make it die even faster).
Changing the fluid anyway will not hurt your tranny at all.
Even in an automatic, you can still change it as long as it isn't already acting up (if it is, then ATF change will make it die even faster).
That car needs a GL4 75w90 gear oil. Plenty of good choices there!
Isn't the OEM fluid Nissan HQ 75w-85? That is what I'd use based on the service manual.
http://g35driver.com/forums/g35-coupe-v3...fferential.html
There is a good video on Youtube of how to change MTF on an Infiniti G37 and that gentleman also uses Nissan HQ 75w-85.
https://www.youtube.com/watch?v=pjEoM9omyik
http://g35driver.com/forums/g35-coupe-v3...fferential.html
There is a good video on Youtube of how to change MTF on an Infiniti G37 and that gentleman also uses Nissan HQ 75w-85.
https://www.youtube.com/watch?v=pjEoM9omyik
Originally Posted By: jbl_91762
...I've heard the horror stories about changing fluids this late in game is not good and have killed trannys...
I would be telling you those same stories if I was in the business of selling transmissions...but Im not...so I can tell you that is nonsense. Change out that fluid and keep on moving down the road.
If a transmission is neglected and/or ran hard, its going to fail. Automatic transmissions fail by design and wear, not because you changed the fluid. Now I will stand back while the rest of the armchair mechanics have a coronary!
...I've heard the horror stories about changing fluids this late in game is not good and have killed trannys...
I would be telling you those same stories if I was in the business of selling transmissions...but Im not...so I can tell you that is nonsense. Change out that fluid and keep on moving down the road.
MolaKule
Staff member
Originally Posted By: tommygunn
Manual transmissions don't get near as hot as automatics. Many of them never require a fluid change at all. Although there's really no such thing as "lifetime ATF" for an automatic transmission, it is OK to do this for a manual in many cases.
Changing the fluid anyway will not hurt your tranny at all.
Even in an automatic, you can still change it as long as it isn't already acting up (if it is, then ATF change will make it die even faster).
As long as any transmission is directly coupled (bolted) to an engine, you're going to have heat conduction from the engine to the transmission and its lubricant.
When changing gears you have clutch slip which causes an increase in temperature.
Besides, in MTs, you don't have a separate cooler for the fluid.
Manual transmissions don't get near as hot as automatics. Many of them never require a fluid change at all. Although there's really no such thing as "lifetime ATF" for an automatic transmission, it is OK to do this for a manual in many cases.
Changing the fluid anyway will not hurt your tranny at all.
Even in an automatic, you can still change it as long as it isn't already acting up (if it is, then ATF change will make it die even faster).
As long as any transmission is directly coupled (bolted) to an engine, you're going to have heat conduction from the engine to the transmission and its lubricant.
When changing gears you have clutch slip which causes an increase in temperature.
Besides, in MTs, you don't have a separate cooler for the fluid.
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Plus, there's no filter on a manual to catch wear metals etc.
The thing about auto transmissions is not false.. changing the fluid is not what is bad. Drain and fill is as safe as anything, but doing a power flush of an auto trans is what MAY cause the problem. This is why some MFR's including Toyota, recommends only a drain and fill and not to flush the transmission. That is what causes the AT issues.
MolaKule
Staff member
Originally Posted By: Rolla07
The thing about auto transmissions is not false.. changing the fluid is not what is bad. Drain and fill is as safe as anything, but doing a power flush of an auto trans is what MAY cause the problem. This is why some MFR's including Toyota, recommends only a drain and fill and not to flush the transmission. That is what causes the AT issues.
Exactly.
That is what we have been trying to tell people for years.
A series of Drains-and-Refills with filter change (if it has a filter) is the most gentle way to clean a transmission.
A "Power Flush" uses a pressurized pump to force fluid through the system, which may force clutch and matal particles into valve body and actuator passages.
I have yet to see a proven, direct cause and effect relationship between Drains-and-Refills and transmission failures.
The thing about auto transmissions is not false.. changing the fluid is not what is bad. Drain and fill is as safe as anything, but doing a power flush of an auto trans is what MAY cause the problem. This is why some MFR's including Toyota, recommends only a drain and fill and not to flush the transmission. That is what causes the AT issues.
Exactly.
That is what we have been trying to tell people for years.
A series of Drains-and-Refills with filter change (if it has a filter) is the most gentle way to clean a transmission.
A "Power Flush" uses a pressurized pump to force fluid through the system, which may force clutch and matal particles into valve body and actuator passages.
I have yet to see a proven, direct cause and effect relationship between Drains-and-Refills and transmission failures.
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Originally Posted By: exranger06
The horror stories you hear only apply to automatic transmissions. You can change manual transmission fluid at any mileage and it will not harm anything.
And even with automatic transmissions you can change fluid at any time. It's a common myth that changing trans fluid at high mileage causes failure, but it's only a common misconception and nothing else IMO.
^ This, but with the added detail that it is a flush at high mileage on an automatic that does the deed.
Manual transmission, no worries!! I'd go with Amsoil myself.
The horror stories you hear only apply to automatic transmissions. You can change manual transmission fluid at any mileage and it will not harm anything.
And even with automatic transmissions you can change fluid at any time. It's a common myth that changing trans fluid at high mileage causes failure, but it's only a common misconception and nothing else IMO.
^ This, but with the added detail that it is a flush at high mileage on an automatic that does the deed.
Manual transmission, no worries!! I'd go with Amsoil myself.
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Use the Nissan oem MTF 75W85.
The old school was people never changed manual transmission gear oil or diff gear oil.
I doubt you will come across many that have failed because of a lack of gear oil change.
I would change it, but would not worry.
I doubt you will come across many that have failed because of a lack of gear oil change.
I would change it, but would not worry.
Originally Posted By: MolaKule
Originally Posted By: Rolla07
The thing about auto transmissions is not false.. changing the fluid is not what is bad. Drain and fill is as safe as anything, but doing a power flush of an auto trans is what MAY cause the problem. This is why some MFR's including Toyota, recommends only a drain and fill and not to flush the transmission. That is what causes the AT issues.
Exactly.
That is what we have been trying to tell people for years.
A series of Drains-and-Refills with filter change (if it has a filter) is the most gentle way to clean a transmission.
A "Power Flush" uses a pressurized pump to force fluid through the system, which may force clutch and matal particles into valve body and actuator passages.
I have yet to see a proven, direct cause and effect relationship between Drains-and-Refills and transmission failures.
I have to respectfully disagree. Have you read up on BGs transmission flush? I dont know about the rest of them but this one is not only legitimate, but a lot of people swear by it. I have it done on every vehicle I own, every 30k miles.
Originally Posted By: Rolla07
The thing about auto transmissions is not false.. changing the fluid is not what is bad. Drain and fill is as safe as anything, but doing a power flush of an auto trans is what MAY cause the problem. This is why some MFR's including Toyota, recommends only a drain and fill and not to flush the transmission. That is what causes the AT issues.
Exactly.
That is what we have been trying to tell people for years.
A series of Drains-and-Refills with filter change (if it has a filter) is the most gentle way to clean a transmission.
A "Power Flush" uses a pressurized pump to force fluid through the system, which may force clutch and matal particles into valve body and actuator passages.
I have yet to see a proven, direct cause and effect relationship between Drains-and-Refills and transmission failures.
I have to respectfully disagree. Have you read up on BGs transmission flush? I dont know about the rest of them but this one is not only legitimate, but a lot of people swear by it. I have it done on every vehicle I own, every 30k miles.
MolaKule
Staff member
Originally Posted By: jbl_91762
I just purchased a 03 Infiniti G35 6mt with 120k miles. It was a one owner vehicle who took very good care of the car and almost all maintenance was done at either Nissan or Infiniti with receipts. But not one showed a trans service and now has 120k miles and I would like to replace the fluid. I've heard the horror stories about changing fluids this late in game is not good and have killed trannys but I'm skeptical on that one. I was planning one using OEM ATF but can you experts enlighten me please.
You want to change the fluid because not only does fluid shear, it has particles left over from the machining at the factory and from normal wear.
In addition, heat oxidizes the fluid and some of the additives in the fluid can become less active.
I just purchased a 03 Infiniti G35 6mt with 120k miles. It was a one owner vehicle who took very good care of the car and almost all maintenance was done at either Nissan or Infiniti with receipts. But not one showed a trans service and now has 120k miles and I would like to replace the fluid. I've heard the horror stories about changing fluids this late in game is not good and have killed trannys but I'm skeptical on that one. I was planning one using OEM ATF but can you experts enlighten me please.
You want to change the fluid because not only does fluid shear, it has particles left over from the machining at the factory and from normal wear.
In addition, heat oxidizes the fluid and some of the additives in the fluid can become less active.
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