Switched to synthetic trany oil, now the tranny is loud

[insdtanoodles]

I just switched to synthetic as I try to get my diesel to get better mileage, currently getting 8L per 100km :cry: and now when I am driving over 60km/h I can hear the transmission whine and it gets louder as I go faster. Is this because the oil is so much thinner then the old stuff I drained out of the tranny? It was like molassis. The oil I am using isnt anything special since it is hard to find any oil that canadian tire doesnt carry so I am using their 75W90 synthetic gear oil. Is there anything I can do to make it quiter or will it adventually quite down on its own, thanks.

[Blades]

oem VW tranny oil or Redline MTL oil

anything else = boom.

[chrissev]

I just switched to synthetic as I try to get my diesel to get better mileage, currently getting 8L per 100km :cry: and now when I am driving over 60km/h I can hear the transmission whine and it gets louder as I go faster. Is this because the oil is so much thinner then the old stuff I drained out of the tranny? It was like molassis. The oil I am using isnt anything special since it is hard to find any oil that canadian tire doesnt carry so I am using their 75W90 synthetic gear oil. Is there anything I can do to make it quiter or will it adventually quite down on its own, thanks.

I don't think that's the correct oil.

[hoyt]

I just switched to synthetic as I try to get my diesel to get better mileage, currently getting 8L per 100km :cry: and now when I am driving over 60km/h I can hear the transmission whine and it gets louder as I go faster. Is this because the oil is so much thinner then the old stuff I drained out of the tranny? It was like molassis. The oil I am using isnt anything special since it is hard to find any oil that canadian tire doesnt carry so I am using their 75W90 synthetic gear oil. Is there anything I can do to make it quiter or will it adventually quite down on its own, thanks.

Is the 75W90 oil a GL4 rated oil?  If not then you got the wrong
stuff in your transmission.  GL5 rated oil is NOT the right stuff, you have
to get a GL4 rated oil.  Redline MTL is GL4 rated.