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Transmission fluid change

MrDad36

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Hi everyone. I’m looking to do a transmission fluid change on my 2019 bighorn 6.4liter 8 speed transmission. I need to replace the pan on this style. Does anyone have a good recommendation as to what fluid to use, where to get it from? Same with the pan. Also, am I just going to let the remaining old 3 quarts mix with the new 5 quarts and call it good? Or should I be more concerned and run it a few hundred miles and change the 5 quarts of fluid a second, or third time?

Thanks.
 
Following.

Curious to how many miles you have and what kind of use the truck sees? Just for the rest of us.


Sent from me
 
Can't help with most of your questions, but here is the equation to know what % of oil is left per change

(((SystemTotalVolume - AmountPerChange)/SystemTotalVolume)^NumberOfChanges) X 100 = % of Old Oil

Assuming 5 New and 3 Old
1 = 37.5%
2 = 14.06%
3 = 5.27%
 
Following.

Curious to how many miles you have and what kind of use the truck sees? Just for the rest of us.


Sent from me
122k. I don’t know if it was done at the 60k interval it probably not. I bought it with 80k miles. I tow 10k lbs often
 
Hi everyone. I’m looking to do a transmission fluid change on my 2019 bighorn 6.4liter 8 speed transmission. I need to replace the pan on this style. Does anyone have a good recommendation as to what fluid to use, where to get it from? Same with the pan. Also, am I just going to let the remaining old 3 quarts mix with the new 5 quarts and call it good? Or should I be more concerned and run it a few hundred miles and change the 5 quarts of fluid a second, or third time?

Thanks.
Your question is confusing. What do you mean 5 new quarts and remaining 3. You pull that pan it takes 7 qts to fill it back roughly. We only use mopar 8and 9 speed fluid. Truck has to be totally level when filling. It will take about 3 qts then put the plug in and fire the truck up. Then it will take about 4 more qts until it’s full. Also there isn’t even a service interval listed for the 8 speed. Customers come I. Requesting one then change their mind after finding out how much the fluid and a pan is.
 
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Your question is confusing. What do you mean 5 new quarts and remaining 3. You pull that pan it takes 7 qts to fill it back roughly. We only use mopar 8and 9 speed fluid. Truck has to be totally level when filling. It will take about 3 qts then put the plug in and fire the truck up. Then it will take about 4 more qts until it’s full. Also there isn’t even a service interval listed for the 8 speed. Customers come I. Requesting one then change their mind after finding out how much the fluid and a pan is.
Hmm. I’ll have to research this again because I googled it and thought I saw it was supposed to be done every 60k miles.

I found a place online who sells the pan (with filter built in it obviously) and 5 quarts. They have a side note that mentions 3 quarts (or liters?) remain in the transmission / torque converter? Or some thing and that in order to get a better flush of the remaining fluid to buy 5 additional quarts for each additional drain / refill…
 
Just curious if anyone does service the transmission. The dealer just told me that they do not service the 8 speed transmission. If they open it to only do a service job, it will void the warranty. I have never heard of such a thing. So if anyone has serviced their transmission, did you void your warranty? My truck is a 22 Power Wagon.
 
Just curious if anyone does service the transmission. The dealer just told me that they do not service the 8 speed transmission. If they open it to only do a service job, it will void the warranty. I have never heard of such a thing. So if anyone has serviced their transmission, did you void your warranty? My truck is a 22 Power Wagon.
My truck is not under warranty so I’ve never been worried about that. I’m sure you read the previous comments on this thread of My concerns doing it myself. I did in fact do it myself and it was very straightforward. I contacted the transmission manufacturer and if I remember correctly they recommend it gets done every hundred thousand miles and under heavy towing as early as every 60,000 miles, but don’t quote me on those numbers. I was at 120+ thousand miles when I did mine. I got the pan through Amazon for less than $300 and I purchased the oil through Ravenol after spending a lot of time researching the fluid specs. Knock on wood, the transmission fluid change went smooth and I have had zero concerns almost 10,000 miles later. If you want more info and specs of what I did, links of where I purchased everything, and some more details as to how I did it myself, let me know.
 
Your question is confusing. What do you mean 5 new quarts and remaining 3. You pull that pan it takes 7 qts to fill it back roughly. We only use mopar 8and 9 speed fluid. Truck has to be totally level when filling. It will take about 3 qts then put the plug in and fire the truck up. Then it will take about 4 more qts until it’s full. Also there isn’t even a service interval listed for the 8 speed. Customers come I. Requesting one then change their mind after finding out how much the fluid and a pan is.

ZF specifically calls for a service interval for the transmission... every 80-120K kilometers (49-74K miles), or 8 yrs.
 
Just curious if anyone does service the transmission. The dealer just told me that they do not service the 8 speed transmission. If they open it to only do a service job, it will void the warranty. I have never heard of such a thing. So if anyone has serviced their transmission, did you void your warranty? My truck is a 22 Power Wagon.

Warranty period is five years or 60K miles..
You can change it once the warranty expires and are still within the range ZF specifies (49-74K miles).
 
I've always used ZF Lifeguard 8 fluid. The Mopar branded stuff is the same, just a different label.

Follow the filling procedure. It's not a dump and fill transmission. It must be filled at temperature.
 
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