ZF6 fluid
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Melting Slicks
Joined: Mar 2006
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From: MichAgain
ZF6 fluid
ZF6 fluid change.
1992 FSM states the fluid "never" needs changing. C'mon, really? FSM also states capacity is 32Oz. Why did the dealer say 3 quarts? Anybody know which is right?
1992 FSM states the fluid "never" needs changing. C'mon, really? FSM also states capacity is 32Oz. Why did the dealer say 3 quarts? Anybody know which is right?
Le Mans Master
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St. Jude Donor '09-'10-'11
I have changed mine once in the 5 years I have owned it, and I will do it again after x amount of track miles.
You have to buy 3 quarts because the capacity is 2.2 quarts. You will not put all 3 in.
You have to buy 3 quarts because the capacity is 2.2 quarts. You will not put all 3 in.
Thread Starter
Melting Slicks
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From: MichAgain
Also, neither my 91 nor 92 manuals give capacities for the rear diff. They do say something about 12 Oz of posi additive, but the bottle from the dealer was only 4oz. Go figure.
Le Mans Master
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From: Akron Ohio
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Thanks, I bought the 92 to make it atrack car and have no idea when the last PM has been done do I'm trying to get all the usual suspects checked/replaced. I thought it odd the manual says it never needs changed, and then the capacity is only 32Oz (1 qt). 1qt seemed way too low, and if 2.2 is the number, then I guess it's off by more than half!
Also, neither my 91 nor 92 manuals give capacities for the rear diff. They do say something about 12 Oz of posi additive, but the bottle from the dealer was only 4oz. Go figure.
Also, neither my 91 nor 92 manuals give capacities for the rear diff. They do say something about 12 Oz of posi additive, but the bottle from the dealer was only 4oz. Go figure.
Race Director
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From: Overland Park Kansas
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Thread Starter
Melting Slicks
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From: MichAgain
Instructor
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From: Charleston WV
Good for you that Amsoil is working in the differential and synchromesh in the transmission.
I remember, something like, synthetic fluid is NOT ecommended by GM for the differential of these cars. I would rather use a dino like Pennzoil 80W90, or a semisynthetic like Walmart's Supertech 80W90. The price per quart is like $4-5. I think Penzzoil has slip additive for the clutch pack. If you buy Supertech, just buy the 4oz (not 7oz) LS additive.
ZFDoc has a good website for these transmissions. According to maker, ZF, a German company who was contracted for the transmissions, the proper fluid is Castrol TWS 10W60, which is what I am using. The transmission fluid life is about 12K max with this fluid according to ZF Doc.
C4ZF6nut
I remember, something like, synthetic fluid is NOT ecommended by GM for the differential of these cars. I would rather use a dino like Pennzoil 80W90, or a semisynthetic like Walmart's Supertech 80W90. The price per quart is like $4-5. I think Penzzoil has slip additive for the clutch pack. If you buy Supertech, just buy the 4oz (not 7oz) LS additive.
ZFDoc has a good website for these transmissions. According to maker, ZF, a German company who was contracted for the transmissions, the proper fluid is Castrol TWS 10W60, which is what I am using. The transmission fluid life is about 12K max with this fluid according to ZF Doc.
C4ZF6nut
The diff takes 1.8 quarts. I use Amsoil severe gear oil on the diff and it has a posi additive in it already. I also use their syncromesh in the tranny. Amsoil products are made to handle the high temps of the track and have worked great for me the last 2 years I have had it in. I also got an extra 2MPG on the highway.
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Le Mans Master
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Good for you that Amsoil is working in the differential and synchromesh in the transmission.
I remember, something like, synthetic fluid is NOT ecommended by GM for the differential of these cars. I would rather use a dino like Pennzoil 80W90, or a semisynthetic like Walmart's Supertech 80W90. The price per quart is like $4-5. I think Penzzoil has slip additive for the clutch pack. If you buy Supertech, just buy the 4oz (not 7oz) LS additive.
ZFDoc has a good website for these transmissions. According to maker, ZF, a German company who was contracted for the transmissions, the proper fluid is Castrol TWS 10W60, which is what I am using. The transmission fluid life is about 12K max with this fluid according to ZF Doc.
C4ZF6nut
I remember, something like, synthetic fluid is NOT ecommended by GM for the differential of these cars. I would rather use a dino like Pennzoil 80W90, or a semisynthetic like Walmart's Supertech 80W90. The price per quart is like $4-5. I think Penzzoil has slip additive for the clutch pack. If you buy Supertech, just buy the 4oz (not 7oz) LS additive.
ZFDoc has a good website for these transmissions. According to maker, ZF, a German company who was contracted for the transmissions, the proper fluid is Castrol TWS 10W60, which is what I am using. The transmission fluid life is about 12K max with this fluid according to ZF Doc.
C4ZF6nut
Race Director
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The other fluid originally recommended has been discontinued by GM. I'd avoid the superceeding fluid since I'm 99% sure it existed before the discontinuation. If it wasn't their 1st choice before, how could it be the best choice now?
I personally think the Castrol stuff is too heavyweight unless you're racing or live in a very hot climate. Redline also recommends a lighter lube (of their internal choices) for that transmission. That helps to reinforce my own personal observation. MTL is Redline's recommended lube. Amsoil has also been well-received.
Instructor
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From: Charleston WV
10W60 is not really a heavy oil, 60 weight equivalent at 100C/212F is only about 30% viscosity of 10W at 0C/32F. Part of the appeal of this viscosity is that it is not a mainline lubricant so it does not have to be energy saving type, with various compromises making it unsuitable.
MTL/MT90 were around 15 years ago, and ZF not supporting it tells me that it is not suitable. Those are manual transmission gear oils with GL-4 rating.
Some transmissions use engine oil for a reason, like Honda, Saab etc. I would rather use Honda MTL fluid which superceded 10W40 SG rated oil recommendation than Redline MTL which is a GL-4 rated gear oil.
Gm synchromesh or Pennzoil Synchromesh has been proposed. I may try the latter sometime, but I am happy with Castrol 10W60.
C4ZF6nut
MTL/MT90 were around 15 years ago, and ZF not supporting it tells me that it is not suitable. Those are manual transmission gear oils with GL-4 rating.
Some transmissions use engine oil for a reason, like Honda, Saab etc. I would rather use Honda MTL fluid which superceded 10W40 SG rated oil recommendation than Redline MTL which is a GL-4 rated gear oil.
Gm synchromesh or Pennzoil Synchromesh has been proposed. I may try the latter sometime, but I am happy with Castrol 10W60.
C4ZF6nut
That was one of two fluids recommended by ZF 15-20 years ago. ZF no longer supports these units. They've LONG ceased testing for compliant lubricants. Alot has happened in 20yrs, so don't assume this is the only fluid that will work (and work well).
The other fluid originally recommended has been discontinued by GM. I'd avoid the superceeding fluid since I'm 99% sure it existed before the discontinuation. If it wasn't their 1st choice before, how could it be the best choice now?
I personally think the Castrol stuff is too heavyweight unless you're racing or live in a very hot climate. Redline also recommends a lighter lube (of their internal choices) for that transmission. That helps to reinforce my own personal observation. MTL is Redline's recommended lube. Amsoil has also been well-received.
The other fluid originally recommended has been discontinued by GM. I'd avoid the superceeding fluid since I'm 99% sure it existed before the discontinuation. If it wasn't their 1st choice before, how could it be the best choice now?
I personally think the Castrol stuff is too heavyweight unless you're racing or live in a very hot climate. Redline also recommends a lighter lube (of their internal choices) for that transmission. That helps to reinforce my own personal observation. MTL is Redline's recommended lube. Amsoil has also been well-received.
Drifting
Joined: Aug 2009
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I'm running the Pennzoil branded scynchromesh - it was the only thing locally available off the shelf. No complaints. 3rd gear sometimes feels like it takes a bit more effort to shift into but it was like that before the new fluid. Might try Amsoil some day to see if it can remedy that issue.
