Six Speed Lubricant

[Alric]

I would like to change the fluid in my 6-speed to Amsoil or another high quality synthetic. The GM shop book recommends P/N 1052931, SAE 5W-30 transmission lubricant. I am looking for suggestions on using a 75W-90 synthetic lubricant. Bad idea; good idea? Any comments will be appreciated

Thanks,

Alric

 

[JonM]

I don't think you want to go with that stuff...If I recall, what you use is similar to motor oil with additives. That 75-90 is differential fluid. The best fluid to use is the BMW M5 motor oil (available only from your local BMW dealer). # 2 is the Red Line manual oil. #3 is the Mobil 1 engine oil used in our cars. Let someone with a comparable setup chime in before you take my advice.

 

[trrgod]

I have an 89 with the ZF 6 speed in it. I put Mobil 1 in it once because I read an article in Vette Mag (I think) suggesting this if the owner wanted to go to synthetic. Later I contacted ZF on the web and was told by their tech not to use anything but the GM fluid or the BMW oil. He said this because using any other fluid will void any warranty. I had no warranty but he scared me enough for me to change the oil back to the GM fluid. By the way, there was no noticeable harm done to the trans that I have noticed. However since the costs of repair or replace on the ZF are astronomical I chose to play it safe. Cluck,Cluck.

 

[Jacob]

I don't think you want to go with that stuff...If I recall, what you use is similar to motor oil with additives. That 75-90 is differential fluid. The best fluid to use is the BMW M5 motor oil (available only from your local BMW dealer). # 2 is the Red Line manual oil. #3 is the Mobil 1 engine oil used in our cars. Let someone with a comparable setup chime in before you take my advice.

Does anyone know the specs on the BMW motor oil? Is it synthetic?

 

[vettl83]

The BMW oil is a 10w 60 synthetic. I purchase mine from Murray BMW in Denver, Colorado. Their price for six quarts including shipping was 81.00. It is the motor oil used in the M-5 BMW's and is made by Castrol I believe but is not listed on Castrol's website. 84 CF 91 ZR-1

 

[bogus]

The oil is Castrol RS, now TWS, 10W60 motor oil.

It is available either at your local BMW dealer, or, a good import auto shop.

for more detailed info, check www.zfdoc.com. He is THE man when it comes to the ZF S6-40 manual gear box.

 

[Alric]

Thanks

I drained and replaced the fluid with Mobil 1 motor oil. The transmission shifts better and the problem is less frequent, although still present. I talked with several people and read as much information a time would allow before using this oil. After driving the car for a few days now, I feel confident in my decision.

Thanks to all who replied,

Alric

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