ZF6 fluid
Race Director
Joined: Oct 2005
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From: Rolla Missouri
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St. Jude Donor '10 thru '25
This is one of the most debated subjects on the forum. Everyone will swear by what their using and say anything else is junk.
I would think either of those two fluids would be ok, since they are both recommended by the zfdoc.
That being said, I am using the Amzoil in mine. If shifts very smooth and I haven't had any problems at all.
I would think either of those two fluids would be ok, since they are both recommended by the zfdoc.
That being said, I am using the Amzoil in mine. If shifts very smooth and I haven't had any problems at all.
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From: San Pedro CA
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Team Owner
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Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
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Team Owner
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From: altered state
St. Jude Donor '05
LIES!!
Actually I spoke to a nameless ZF guru last year and he was experimenting with running corn oil in them. Okeeee....
Team Owner
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
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From: Sun city CA
Instructor
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I used the factory spec oil. Went to the Chevy dealer. Sorry but I don't have the part number. The factory oil is good. The BMW oil is recommended also. You should be able to get the BMW (Castrol oil) from a dealer also. I would definitely choose one of these choices as recommended by ZF. It is not standard 10X30.
Safety Car
Joined: Jul 2001
Posts: 4,871
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From: Detroit's West Side MI
No, Spaniards and Mexicans. Apparently you're not Bi...
Lingual.
I use the BMW Castrol, it's convenient because it's the same stuff I have to put in my M3 - I have it lying around the garage. Works fine, many many track days and the transmission has not exploded.
Lingual.
I use the BMW Castrol, it's convenient because it's the same stuff I have to put in my M3 - I have it lying around the garage. Works fine, many many track days and the transmission has not exploded.
Race Director
Joined: Sep 2001
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From: NEwhere Ohio
DO NOT USE THE CASTROL fluid in your ZF6 transmission.
ZFDOC lives in Arizona which has Disney World type weather compared with where I live in ohio. The Castrol BMW crap fluid takes time to warm up and still may never work right. I realize he has devoted his life to the ZF6, but, as a ZF6 user, I do not agree with his recommendation.
ZFDOC also told me I needed either my clutch hydraulics replaced/bled properly (which I did) or my transmission synchros rebuilt (at a cost of thousands of dollars) when I described to him the symptoms I had (grinded shifts, missed shifts under WOT runs, etc.). In some cases the gear lever would not move into the next gear during WOT type runs.
When I switched back to the proper GM pn 5w-30 factory fill all these problems disappeared.
I was going to buy a new transmission.
So the choice is yours:
Option A: Run with what GM factory engineers recommend you run with and no-ones complained here about missed shifts, grinded gears, etc.
Option B: Try risky BMW Castrol 10W-60 where some claim its great and others claim it can ruin your car.
Id rather try 'tried and true' option A. But thats just me. You'll do whatever you want.
ZFDOC lives in Arizona which has Disney World type weather compared with where I live in ohio. The Castrol BMW crap fluid takes time to warm up and still may never work right. I realize he has devoted his life to the ZF6, but, as a ZF6 user, I do not agree with his recommendation.
ZFDOC also told me I needed either my clutch hydraulics replaced/bled properly (which I did) or my transmission synchros rebuilt (at a cost of thousands of dollars) when I described to him the symptoms I had (grinded shifts, missed shifts under WOT runs, etc.). In some cases the gear lever would not move into the next gear during WOT type runs.
When I switched back to the proper GM pn 5w-30 factory fill all these problems disappeared.
I was going to buy a new transmission.
So the choice is yours:
Option A: Run with what GM factory engineers recommend you run with and no-ones complained here about missed shifts, grinded gears, etc.
Option B: Try risky BMW Castrol 10W-60 where some claim its great and others claim it can ruin your car.
Id rather try 'tried and true' option A. But thats just me. You'll do whatever you want.
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
)
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From: NEwhere Ohio
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From: altered state
St. Jude Donor '05
I think the General had a good idea of whats going on.