I'm a little confused about what oil to use in my 73 CSi rear diff( non limited slip ). I've searched the site and thought a GL4 was needed. I spoke with redline oil who indicates an extreme pressure hypoid gear oil (GL5) is needed and recommends the 75W90. If I were to use 75W90ns, he recommends adding a friction modifier. I also spoke with Carl at LaJolla who states either can be used in my diff, but a limited slip with 75W90ns would need a friction modifier. The above oils I'm referring to are Redline. Does anyone have any other recommendations. Thanks, Jeff.
rear diff oil
- Thread starter Jeff
- Start date
cpeavey
Well-Known Member
Jeff,
Have you read this article on Redline's site? It helped clarify this topic for me, especially across generations of BMWs.
http://www.redlineoil.com/news_article.aspx?id=13
Charlie
Have you read this article on Redline's site? It helped clarify this topic for me, especially across generations of BMWs.
http://www.redlineoil.com/news_article.aspx?id=13
Charlie
hello
I remember reading a lot of semi-technical semi-commercial information on this topic
(Remember that you are never reading a 100% technical document if it has the brand´s name on it)
So after some reading I decided to use CASTROL 80w90 (plain, no aditives, nothing) for my E9, 1971 3.0 CS, remember it is a 38 year old car
It is still alive and with good health
hope it helps
I remember reading a lot of semi-technical semi-commercial information on this topic
(Remember that you are never reading a 100% technical document if it has the brand´s name on it)
So after some reading I decided to use CASTROL 80w90 (plain, no aditives, nothing) for my E9, 1971 3.0 CS, remember it is a 38 year old car
It is still alive and with good health
hope it helps
blumax
(deceased)
Differential lube oil
Look up SWEPCO--south west petroleum company--not too well known to BMW owners--they're suppliers to heavy off-road equipment operators, heavy over the road and many race applications--all demanding extreme reliability.
My mechanic with 30+ years of BMW specialty experience has used it for over that time without any failures--the BLUMAX has been lubed with it since its first diff lube change at about 30,000 miles without issue.
Look up SWEPCO--south west petroleum company--not too well known to BMW owners--they're suppliers to heavy off-road equipment operators, heavy over the road and many race applications--all demanding extreme reliability.
My mechanic with 30+ years of BMW specialty experience has used it for over that time without any failures--the BLUMAX has been lubed with it since its first diff lube change at about 30,000 miles without issue.