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ZF 8-speed fluid change

Squatch

Squatch

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Figured I’d start this thread because the idea of lifetime transmission fluid from my perspective is nothing more than planned obsolescence by automaker. ZF recommends changing the fluid regularly, they made the transmission, so I am changing it every 60k miles. The 8 speed 1500 driving dudes have been doing it on their own, without special equipment for years, so I suspect our situation ain’t much different. Maybe we can compile information about how to do it here.
 
Interesting that ZF doesn't talk about making sure the trans pan rail is level, not just the vehicle being on a flat surface/lift. I'm pretty sure the Mopar manual makes an issue of that.
 
I think the ZF manual is assuming it is mounted approximately level in a car application. On our truck I think you gotta jack it up in the rear until pan is level to do the job.
 
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SQUATCH said:
Most of these trannys are mounted level in cars. I think the ZF manual is assuming it is mounted level in the car. On our truck I think you gotta jack it up until pan is level to do the job.
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Really? I've built a ton of cars. Most drivelines are not level front to back in my experience. Then, neither u-joint should be "straight" either. not supposed to be.
 
Wmhjr said:
Really? I've built a ton of cars. Most drivelines are not level front to back in my experience. Then, neither u-joint should be "straight" either. not supposed to be.
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Thats just what I read, that they are at least more level in the sedans they put them in than the trucks, but again, I just read that from somewhere I can’t even remember. I have seen videos where guys have done it with truck on the ground, or with rear of truck jacked so tranny was level. I think it is supposed to be level...but not sure.
 
SQUATCH said:
Thats just what I read, that they are at least more level in the sedans they put them in than the trucks, but again, I just read that from somewhere I can’t even remember. I have seen videos where guys have done it with truck on the ground, or with rear of truck jacked so tranny was level. I think it is supposed to be level...but not sure.
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All I can say that I have literally built - from the ground up - a number of cars. I have a '66 GTO Pro-Touring build I did about 10 years ago as an example. Put a Tremec 600 manual behind a built standard block - had to fabricate new rear mounts, have Inland Empire build a new aluminum driveshaft to my specs, etc. The engine and tranny most definitely were NOT supposed to be "level", and I had to spend a fair amount of time getting my driveline angles set right - including adjustable upper and lower rear control arms to make sure I had correct input and output angles coming from my trans output shaft to the driveshaft, and from the driveshaft to the yoke on the Moser rear end I had built. Same thing for two other cars I built. Maybe new cars are different in terms of engine mount, but I also know that the 5.3 gasser in a '00 Silverado definitely did NOT sit level front to rear. Part of this is because in many applications, the centerline of the transmission output shaft will be lower than the rear axle pinion if the engine and transmission are mounted level.

But who knows? Maybe something has changed in newer vehicles?
 
Yeah, I might be wrong and by the sounds of it I probably am. I am not sure if the tranny is supposed to be level itself when the fluid level is checked at temperature or if truck on all four tires is where it should be when you bleed fluid at temperature.
 
I'm here to state the 8 speed is awesome and I plan on changing at 70-75k as I don't tow a ton. I have the 2500 for payload capacity and hauling but rarely will get to maxing that out.
 
1HasBeen said:
Interesting that ZF doesn't talk about making sure the trans pan rail is level, not just the vehicle being on a flat surface/lift. I'm pretty sure the Mopar manual makes an issue of that.
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What does the mopar manual say? I know when I have seen some videos of guys doing this I have seen them jack up the rear axle until the transmission pan is level, but I have also seen it with all tires on the ground. Don’t know which is right?
 
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