Transmission pan and fluid change questions

[andymax]

thanks! other than this ridiculous drain/fil/check procedure this is the best transmission I've ever driven...I've had three of them in BMW, Jeep and now Ram. I HATE this part.

 

[jws123]

hahaahaha...

Funny you say that. Other than my 09 having a lot of miles. The real reason I got my 2018 was for ZF trans. Everyone said how bad ass it is and how faster the truck felt. Like you I miss my old 5 speed too. Installed a 4x4 dorman pan with the drain plug and I did drain and fills once a year. Don in 20 minutes.

The 8 speed honestly wouldnt be to bad even with the annoying fill procedure If it didnt shudder into 2nd gear sometimes aswell as downshifts are really annoying. Its just not a smooth transmission at all I only have 116k on mine my friends has 70k same thing. I dont feel as confident as I did with my 2011 that had 230k I refuse to tow anything really heavy now long distance like I did with my 2011 in fear il blow it up I always use fathers 2500 for that now.. The only thing I like about the 8 speed as i can fly down the parkway effortlessly with cruise control get aorund 18mpg its a cruiser.

 

[BlownGP]

Mine only had about 50K and it shifts smooth but what I don't like it the jerkingness when you left off the gas to coast and it will be in 4th gear. Then when you get back on it. It jumps, Plus I have bump/jerk when slowing to a stop that no one seems to have any idea what causes it.

 

[Wild one]

CONFUSED..PLEASE HELP. I'm in the middle of the fluid replacement. Hangman and at least one other say to raise the rear of the truck to get the tranmission perfectly level, which requires the rear tires be off the ground by 9 inches! If I watch the videos, not one single video for ANY ZF 8speeds require this step...only that the Vehicle is level, whether lifted off the ground or not. So anyone KNOW which is correct?

These are the instructions that come with a brand new truck ZF when you buy the transmission from the dealer.Cost me a few bucks to get them,lol. Read the very first high lighted paragraph

 

[HEMIMANN]

These are the instructions that come with a brand new truck ZF when you buy the transmission from the dealer.Cost me a few bucks to get them,lol. Read the very first high lighted paragraph

Hey @Wild one , what's with the no dye statement? Is this the Germans being over-**** again? I've read guys using Amsoil Multivehicle ATF with good success, even Valvoline MaxLife ATF. I'm assuming both are dyed red?

 

[andymax]

These are the instructions that come with a brand new truck ZF when you buy the transmission from the dealer.Cost me a few bucks to get them,lol. Read the very first high lighted paragraph

thank you. I saw this earlier and this is exactly why I'm confused. I've changed trans fluid on two other ZF's, one in a Jeep and one in a BMW. Never leveled the tranny, always leveled the vehicle. Additionally, not one single other point of reference, such as google searching, youtube videos (I think I watched them all!) and even this ZF service flow chart say anything about bringing the transmission itself to level. In fact the chart linked below says to be sure the vehicle is horizontal. And the other slightly confusing thing is the highlighted paragraph says to bring the trans rail "level to the floor". Level to the floor makes no sense to me. Level makes perfect sense.

https://aftermarket.zf.com/app/controller/ti/download/Binary/22f16dae-c571-11ec-a2e7-00505690da53.pdf

 

[Wild one]

thank you. I saw this earlier and this is exactly why I'm confused. I've changed trans fluid on two other ZF's, one in a Jeep and one in a BMW. Never leveled the tranny, always leveled the vehicle. Additionally, not one single other point of reference, such as google searching, youtube videos (I think I watched them all!) and even this ZF service flow chart say anything about bringing the transmission itself to level. In fact the chart linked below says to be sure the vehicle is horizontal. And the other slightly confusing thing is the highlighted paragraph says to bring the trans rail "level to the floor". Level to the floor makes no sense to me. Level makes perfect sense.

https://aftermarket.zf.com/app/controller/ti/download/Binary/22f16dae-c571-11ec-a2e7-00505690da53.pdf

In most instances the transmission is sitting fairly level in vehicles,in the trucks it's not. Those are the instructions that come with a trucks 8 speed,whether you want to follow them is up to you,but alot of guys have had issues when filling them with-out leveling the transmission,and have to go back and level the pan rail to get the proper fluid level.Believe who you want,me i'm more inclined to believe the instructions that come with the transmission

 

[Wild one]

Hey @Wild one , what's with the no dye statement? Is this the Germans being over-**** again? I've read guys using Amsoil Multivehicle ATF with good success, even Valvoline MaxLife ATF. I'm assuming both are dyed red?

I think it's the die used to find oil leaks is the die they're referring to,if you read it,it sounds like a black light can be used to find leaks with the ZF fluid

 

[stenerson]

Hey @Wild one , what's with the no dye statement? Is this the Germans being over-**** again? I've read guys using Amsoil Multivehicle ATF with good success, even Valvoline MaxLife ATF. I'm assuming both are dyed red?

This from the All Data DYI app: "Oil dye is not required to find leaks in the 8HP transmission. The oil dye can cause shift quality issues and is not recommended. The 8HP fluid has illuminance that is visible under a black light."

 

[HEMIMANN]

This from the All Data DYI app: "Oil dye is not required to find leaks in the 8HP transmission. The oil dye can cause shift quality issues and is not recommended. The 8HP fluid has illuminance that is visible under a black light."View attachment 523991

Confused me because the exact reason why transmission oil is dyed red is to identify leaks - to differentiate from engine oil and engine coolant using color.

That is what I was told working for Mobil Oil Corporation.

 

[andymax]

In most instances the transmission is sitting fairly level in vehicles,in the trucks it's not. Those are the instructions that come with a trucks 8 speed,whether you want to follow them is up to you,but alot of guys have had issues when filling them with-out leveling the transmission,and have to go back and level the pan rail to get the proper fluid level.Believe who you want,me i'm more inclined to believe the instructions that come with the transmission

I am most certainly not questioning you, rather it's your post that has me so concerned that leveling the vehicle is incorrect. I've not yet found an instance where guys have had issues...maybe I'm just plainly missing that, but thats why I'm so concerned.

Oh and the fact that the other ZF document says to assure the vehicle is level. I reached out to ZF directly, hoping they respond.

 

[Wild one]

I am most certainly not questioning you, rather it's your post that has me so concerned that leveling the vehicle is incorrect. I've not yet found an instance where guys have had issues...maybe I'm just plainly missing that, but thats why I'm so concerned.

Oh and the fact that the other ZF document says to assure the vehicle is level. I reached out to ZF directly, hoping they respond.

Crawl under your truck and look at the angle the transmission sits at,then look at where the fill plug is located on the transmission,then imagine the transmission pump running and constantly sucking fluid out of the sump.
Then go look at how the 8 speed sits in a car,and imagine how much more fluid it'll take before the fluid runs out the fill/level plug. Common sense will tell you that you'll get more fluid into the cars 8 speed when the car is sitting level in comparision to how much fluid you'll get into the trucks 8 speed when the truck is sitting level.

 

[andymax]

So this past Wednesday I reached out to ZF directly because I wanted an answer straight from the source. I am attaching a doc to show the exact exchange I had with them. Do with this what you will. For me this issue is put to bed. I followed their instructions and for two days and 180miles my tranny is running at 185 in town on a 94 degeree day, and 179 on the freeway.

I'm inserting an image of that doc to make it easier to see.

 

[Wild one]

So this past Wednesday I reached out to ZF directly because I wanted an answer straight from the source. I am attaching a doc to show the exact exchange I had with them. Do with this what you will. For me this issue is put to bed. I followed their instructions and for two days and 180miles my tranny is running at 185 in town on a 94 degeree day, and 179 on the freeway.

I'm inserting an image of that doc to make it easier to see. View attachment 524158

I'd lay odds thats a generic answer. Couple questions,why would they send instructions specifically stating to level the pan rail with a "brand new " truck transmission,if they didn't want you to level the transmission,and not the truck,i highly doubt they'd send those instructions right in the warrenty booklet, if they figured the truck needs to be level,and not the transmission.The other question ,the cars and trucks use the same transmission pan,but the transmission sits level in the cars,not downhill like it does in the trucks,and if you've already done the fluid level check,you'll have observed where the fill plug is at on the transmissions. Which transmission do you think you'll get more fluid into if both vehicles are sitting level,little tidbit for you,it won't be the truck,lol. I'm more inclined to believe the instructions sent with a transmission that's specific to the trucks,then a generic answer. If your transmission is working fine, all the power to you,but there's been a fair number of guys who've had issues with their 8 speeds after servicing them and filling the transmission while the truck is level,they then go back and level the pan rail and get another litre of fluid into the transmission,and their shift issues go away. I Know my Challenger will take more fluid then the truck will when the car is sitting level,compared to the truck,and they both use the same transmission pan. Take your truck out and floor it from a stop and let it run up to the factory shift point of roughly 5600rpm, through at least 4 gear changes,if you have no slip issues then you're good to go

 

[HEMIMANN]

Lawyers write the instructions. I'm surprised such instructions are even published. Then again, Germany isn't a litigious (money for nothing) society like USA.

 

[Wild one]

When i replaced my 8 speed,the dealer used the trucks VIN number to order the transmission,so that they got the right transmission,and the fill procedure was a laminated instruction sheet,included with the warrenty booklet that's specific to the truck transmissions. If they didn't figure the transmission needed to be level,i highly doubt they'd of sent a laminated instruction sheet,specifically stating to level the pan rail , and make it the very first high lighted paragraph,that's high lighted more then any of the other instructions on the sheet. Owning both a car and truck with the 8 speed,and observing where the fill plug is,the cars transmission will take alot more fluid to fill then the truck will,if both are sitting level to the ground.

 

[18CrewDually]

I can't even wrap my head around why it would even be questioned when it's been posted in black & white (green ) ? Plus the directions make sense and aren't confusing. I know what I'd do.

 

[andymax]

I can't even wrap my head around why it would even be questioned when it's been posted in black & white (green ) ? Plus the directions make sense and aren't confusing. I know what I'd do.

Three reasons I can think of off the top of my head. One is what I posted from ZF directly. Secondly, there is a ZF document attached below that says nothing whatsoever about leveling the transmission, but does in fact say to level the vehicle. Thirdly, I called a highly regarded transmission shop and asked them. He looked up my specific truck on his database and told me clearly that leveling the vehicle is the proper procedure, according to ZF. AFAIK, there is only one supporting document to the contrary, which is aformentioned green document. Please show me otherwise if you or anyone else has anything other than anecdotal information

BTW, I emailed that green doc to ZF...I'm looking forward to the response.

And for the record, I am still not saying I'm right and anyone else is wrong, (though I get the distinct impression I'm being told I'm wrong), I am honestly trying to get to the bottom of this clearly important issue for those of us that care about the best care and maintenance.

 

[18CrewDually]

The illustration does show the transmission pan sealing surface level. And the fill plug being in the rear, if the trans is tilted back like it is in the trucks, then you will not be able to fill it to the proper capacity.


This question for anyone recently that pulled the fill plug when the truck was on its tires (not jacked to make the flange level), Did it show over full from the factory? If it did then it would show the transmission should be leveled to get the proper amount.

 

[andymax]

When i replaced my 8 speed,the dealer used the trucks VIN number to order the transmission,so that they got the right transmission,and the fill procedure was a laminated instruction sheet,included with the warrenty booklet that's specific to the truck transmissions. If they didn't figure the transmission needed to be level,i highly doubt they'd of sent a laminated instruction sheet,specifically stating to level the pan rail , and make it the very first high lighted paragraph,that's high lighted more then any of the other instructions on the sheet. Owning both a car and truck with the 8 speed,and observing where the fill plug is,the cars transmission will take alot more fluid to fill then the truck will,if both are sitting level to the ground.

Question for you...do you happen to know, did the transmission ship to you with any fluid in the pan? Since that green document is shipped with new transmissions, is it possible that leveling the transmission upon first startup is to fill areas/ports, etc that may have been drained prior to shipping? We all know that doing a normal drain/fill yields a fair amount less fluid upon draining than the transmission actually holds (not to mention the lines to the trans cooler). Seriously, I'm trying to understand why ZF would have different instructions and my working theory is the fill instructions are different for new/replacement transmissions than for maintenance drain and fills.