How do you level 8hp70 for fluid change/fill?

[PoMansRam]

There is a member on here who tows TT for a living with his Ram 1500 EcoDiesel, current mileage on his 8HP70 trans is 700K miles. He changes his every 100K miles.
ZF the engineers of the 8HP line of transmissions suggest about 80K Kilometers

If he's the fella I'm thinking of, he uses Valvoline Maxlife ATF as well.

 

[crash68]

If he's the fella I'm thinking of, he uses Valvoline Maxlife ATF as well.

Yes, I should have noted that.

 

[chrisbh17]

I know how I'd "level" mine.

By measuring the amount of fluid that came out and being sure I'm putting back in that exact amount. LOL.

If I thought the factory level was off in the first place, I'd just jack up the ****-end of the truck a bit, eye ball it and check the pan rail with a bubble level.

Refill with a suitable ZF8 fluid that's not $20-30/qt and be done with it.

But if most it even all of the fluid is sitting in the rear of the pan (because it's slanted to the back without raising the rear of the truck) you are potentially missing a lot of dirty fluid to drain that way

Sent from my Pixel 3 XL using Tapatalk

 

[kayla02110]

Let it drain with the tires on the ground. Once the pan/filter is off use the machined surface and lift the rear axle up to level. Depending on your stance that may vary from 10-13”. You’ll need to let the rear spin into second slowly, no worries just watch your EVIC on the trans temp and practice the procedure so you don’t overheat the fluid.

View attachment 217229

Just a question on Step#9: How do I know when I am in 2nd gear?

And when going from Step#7 to #8, i keep my foot on the Brake the whole time, right?

Also, Step #10 to #12, is my foot on the Brake the whole time?

And then after Step#14, after driving around for a bit should I check my levels again? Presumably when the truck cools down, right? If I do this, do I do it when the truck is level, or Rear End jacked up again?

Thanks guys!!

 

[RamDiver]

Just a question on Step#9: How do I know when I am in 2nd gear?

And when going from Step#7 to #8, i keep my foot on the Brake the whole time, right?

Also, Step #10 to #12, is my foot on the Brake the whole time?

And then after Step#14, after driving around for a bit should I check my levels again? Presumably when the truck cools down, right? If I do this, do I do it when the truck is level, or Rear End jacked up again?

Thanks guys!!

Don't wait for Tim to respond.



.

 

[NETim]

You use the "+" and "-" buttons on the steering wheel to know what gear the truck is currently in. The EVIC displays the current gear.

Keep the brakes on from step 7 to 8. Same for 10 to 12. The only time the brakes aren't applied is when you're taking it to 2nd gear.

Many do a repeat DNF shortly after the first in an effort to get even more old fluid out of the ZF. Obviously, you repeat the process in the exact same manner.

Always check the level with the ZF as level as possible, in the specified temp range with the engine running. If you remove the fill plug with the engine off and/or the ZF NOT level, fluid will gush out of the fill port. You will NOT have the correct fill on the ZF as a result.

 

[Wild one]

Just a question on Step#9: How do I know when I am in 2nd gear?

And when going from Step#7 to #8, i keep my foot on the Brake the whole time, right?

Also, Step #10 to #12, is my foot on the Brake the whole time?

And then after Step#14, after driving around for a bit should I check my levels again? Presumably when the truck cools down, right? If I do this, do I do it when the truck is level, or Rear End jacked up again?

Thanks guys!!

It's pretty easy to tell when it shifts into 2nd when the wheels are in the air,if not,then start with the transmission in 1st,and take it up to around 1500/1800 rpm,then manually shift it into 2nd.
I always take my foot off the brake on step 10,that'll allow the rear tires to turn,and that's why you want to step on the brakes again,before putting it back into park on step 12.I don't think it really matters if you let off the brakes between step 10 and 12,but the way i read it,i've always let off the brakes.
The whole idea of the procedure is to fill all the clutch circuits,before checking the fluid level,and probably as long as the trucks running and has went through a gear change,odds are the clutch circuits will be full
Never hurts to recheck the fluid after driving it around and getting the transmission hot.
You still need to do it cold,with the truck jacked up,and running,"do not pull the fill plug with-out the truck running"
Start with a cold transmission,as by the time you get through the procedure,it'll be starting to get warm.The colder you can keep the transmission during the procedure the better.The sheet says 122F,but if you can get everything done by the time it hits 112 to 115F the better off you'll be

 

[kayla02110]

Thanks for the quick response guys! @NETim could you please clarify how to use the + and - buttons? I can press them, but it just lets me keep going up or down as much as I want to 8. Do I just press it and leave it at 2, and it will automatically go to 2nd gear? Do I need to press the gas or anything up to a specific RPM? (I will be doing this with rear wheels in the air)

Thanks again guys!

 

[ToddS1971]

Just did this on mine last weekend. Had to jack up the back up right about 9 1/2 inches to get the pan rail level. I was on an absolute flat surface, my garage floor. I assume it's level because in neutral it didn't want to roll forward or backwards. Garage pads are supposed to be level and apparently mine is. Went with MaxLife multi vehicle fluid. 8 and 9 speed approved and WAY cheaper. Shifts and acts fine a week later.

 

[NETim]

Thanks for the quick response guys! @NETim could you please clarify how to use the + and - buttons? I can press them, but it just lets me keep going up or down as much as I want to 8. Do I just press it and leave it at 2, and it will automatically go to 2nd gear? Do I need to press the gas or anything up to a specific RPM? (I will be doing this with rear wheels in the air)

Thanks again guys!

All you have to do is get it to display "8". This way the EVIC will tell you when you're in 1st and 2nd etc. Just accelerate until it shifts to 2nd and try to hold it there. It's a bit un-nerving to do this but as long as you have the rear wheels off the ground and the front wheels chocked, you should be just fine.

This is just ZF's way of ensuring the tranny passages are full of fluid so you get an accurate fill.

 

[Sherman Bird]

Okay, here's a dumb question but what exactly is the "pan rail" ?

It's the lip knurled up on the outermost plane of the bolt channel!

 

[Sherman Bird]

If he's the fella I'm thinking of, he uses Valvoline Maxlife ATF as well.

There are SO many variables! I go back in my wayback mind to the late 1970's.....
I was working as a tech in a Chevy dealer. It was directly on Interstate 10, so we got a LOT of out of town business.
One day a fellow came in with a 4-door crewcab C-35 single wheel truck. This 4 door configuration akin to what's common today was fairly rare back in those days. Said truck was pulling a travel trailer.

Anyhoo, he hailed from Illinois and had us do an oil change and an alignment. While under the hood, I noticed 2 home made "boxes" made of sheet metal, one on each fender liner. (Those were made of steel back then, and were devoid of all the goodies which populate our current underhood).

From each of these boxes ran hydraulic quality flex hoses; one for engine oil and the other for ATF. Both boxes had blower motors on top of them, and were wired to temperature sensor circuits to turn them on a a temp chosen by the customer. (He was a mechanical engineer, retired from GM).

Showing my fascination and interest in the specifics of these neat-o devices, He admonished me to pull out the transmission dipstick and observe how clean and clear the fluid was. (Uh, you DO remember trans dipsticks, right?)

At 100,000 miles, the customer swore that the fluid was ORIGINAL! He'd never changed it! (The engine was a 454 and the trans was a TH400)

Things have evolved a great deal since then. I do wonder, however, what if a person were to modify their truck at brand new to control severe heat, such as this man had, how long would OE trans fluid last? After all, heat is THE number one correlative aspect in automatic transmission failures.

 

[Wild one]

There are SO many variables! I go back in my wayback mind to the late 1970's.....
I was working as a tech in a Chevy dealer. It was directly on Interstate 10, so we got a LOT of out of town business.
One day a fellow came in with a 4-door crewcab C-35 single wheel truck. This 4 door configuration akin to what's common today was fairly rare back in those days. Said truck was pulling a travel trailer.

Anyhoo, he hailed from Illinois and had us do an oil change and an alignment. While under the hood, I noticed 2 home made "boxes" made of sheet metal, one on each fender liner. (Those were made of steel back then, and were devoid of all the goodies which populate our current underhood).

From each of these boxes ran hydraulic quality flex hoses; one for engine oil and the other for ATF. Both boxes had blower motors on top of them, and were wired to temperature sensor circuits to turn them on a a temp chosen by the customer. (He was a mechanical engineer, retired from GM).

Showing my fascination and interest in the specifics of these neat-o devices, He admonished me to pull out the transmission dipstick and observe how clean and clear the fluid was. (Uh, you DO remember trans dipsticks, right?)

At 100,000 miles, the customer swore that the fluid was ORIGINAL! He'd never changed it! (The engine was a 454 and the trans was a TH400)

Things have evolved a great deal since then. I do wonder, however, what if a person were to modify their truck at brand new to control severe heat, such as this man had, how long would OE trans fluid last? After all, heat is THE number one correlative aspect in automatic transmission failures.

A few guys are using Caulk04's bypass which drops the 8 speeds temperatures by a noticable amount,as it gets rid of the factory thermostat installed in the cooler lines.
The one glaring differance is the temps between the 1500's 8 speed that uses the thermal management unit to heat the transmission fluid and their thermostat which keeps the 1500's 8 speed at 185+ F,and the 3/4 ton truck's that don't have a thermal management unit and a lower spec thermostat.The Heavy Duty trucks run under 170F when towing 7,000+ lbs,and will run down the road empty in the 160 to 165F range.So even Ma Mopar knows to run the 8 speed cooler when it's in something that works the transmission hard.
The cars also don't use the thermal management unit to heat the fluid in their 8 speeds,and on a leasurely back road tour at 50 mph,my wifes 1320 Challenger,which has a factory high stall torque convertor and differant shift mapping from a normal 6.4 ScatPack Challenger or Charger will take 50+ miles to get to 150F,and won't get over 160F if i don't boot it several times.
The other thing i noticed,is the temps the 8HP90 runs in my buddies Demon and Red Eye,he let me drive both on a 90 degree day,as he wanted to sit in the pass seat when somebody he trusted to drive the hell out of both cars with-out crashing them on him,and i did 6 back to back drag strip style launches (both cars are on drag slicks) and ran both cars up to 150+ mph,plus we put over 30 miles of spirited driving on both,and i couldn't get the 8HP90's in either car over 155F,in fact his Demon with a 180 thermostat on the 840 horse tune didn't get over 148F.
I would guess the optimal temp for the 8 speeds is closer to 155F/160F then it is to 185+F like they run it in the 1500's.Personally i think they run the the 8 speed in the 1500's that hot,just for that last little bit of corporate milege number,as the 1500's outsell everything else FCA/Stellentis sells combined

 

[crash68]

I would guess the optimal temp for the 8 speeds is closer to 155F/160F then it is to 185+F like they run it in the 1500's.Personally i think they run the the 8 speed in the 1500's that hot,just for that last little bit of corporate milege number,as the 1500's outsell everything else FCA/Stellentis sells combined

Probably true about temps but on the other hand there's very few reported transmission failures or mentions of the fluid being burnt even running the higher temps.
Probably a situation of old skool ways being applied against modern engineering.

 

[Wild one]

Probably true about temps but on the other hand there's very few reported transmission failures or mentions of the fluid being burnt even running the higher temps.
Probably a situation of old skool ways being applied against modern engineering.

Lots of guys have shown pictures of the fluid they've drained from their 1500's 8 speeds,and it's definitely showing signs of being heat abused.I don't think it has anything to do with old school ways,as much as it has to bring FCA's/Stelentis's corporate milege numbers up,prime example being the ones i listed Phil,the Heavy Duties and the real high horsepower cars they sell,like the 2018 Demons and Red Eyes.I'm curious on what they run the 8 speed at in the 1000 horse Demon 170,as it's had a pile of upgrades to live behind the 1025 horse motor in those cars

 

[Sherman Bird]

Probably true about temps but on the other hand there's very few reported transmission failures or mentions of the fluid being burnt even running the higher temps.
Probably a situation of old skool ways being applied against modern engineering.

Think again! There is nothing "old school" about these modern transmissions! The engineering inside these new transmissions is awesome.... something very clever. These transmissions no longer employ bands OR accumulators. Nowadays, they use something called "compensation" oil which is modulated through the valve body and solenoid controlled valves due to leaps and bounds advancement in computer controls.

The simple fact is, they can control everything about shift feel, TCC events and feel, and all manner of behavior of the gear box.

Variable output pumps address lower parasitic loads when torque demand is low.
The old school Trans fluid (Mercon/Dexron III, ATF+4) was a multi viscosity oil at 15W cold/ 7.5W hot. The temperature transition point was about 110- 115 degrees F.

The new ULV (Ultra low Viscosity) fluid is another step in reduction of parasitic loss. Almost all ATF is synthetic to aid in thermal stability. The one place they cannot get rid of high scorching heat is in the torque converter. That heat must be transferred to an outside place via a cooler. These thermostats in the new units are necessary in cold climes, because ATF is designed to do optimal work at 115 degrees or higher. The fact that TCC is commanded in first gear at speeds as low as 16 MPH in some models is CAFE inspired, not life extension of the unit, and exacerbates heat related failures.
There are some tuners able to program the TCC to slip a lot less and delayed in coming on at higher gear ranges and higher MPH.

AFM, or DOD also contributes to early transmission death due to high TCC slippage to cushion the transition from 4-8 or 8-4 cylinder operation. Some tuners defeat AFM/ DOD.

 

[kayla02110]

All you have to do is get it to display "8". This way the EVIC will tell you when you're in 1st and 2nd etc. Just accelerate until it shifts to 2nd and try to hold it there. It's a bit un-nerving to do this but as long as you have the rear wheels off the ground and the front wheels chocked, you should be just fine.

This is just ZF's way of ensuring the tranny passages are full of fluid so you get an accurate fill.

Sorry still a little confused. I can get it to display the 8….but are you saying that if I press the accelerator a little “2” should pop up somewhere on the screen to tell me when I’ve hit 2nd gear? Or is it just something I gotta feel for by hitting the accelerator and feeling some short of feeling?

Sorry for all the questions lol

 

[Wild one]

Sorry still a little confused. I can get it to display the 8….but are you saying that if I press the accelerator a little “2” should pop up somewhere on the screen to tell me when I’ve hit 2nd gear? Or is it just something I gotta feel for by hitting the accelerator and feeling some short of feeling?

Sorry for all the questions lol

You should feel it shift into 2nd when the tires are in the air and spinning.Hit the (-) button on the steering wheel,and then you can manually select the gears,it should show in your evicc/cluster what gear the transmission is in.It doesn't take much gas pedal to get it to shift to 2nd when the rear tires are off the ground

 

[NETim]

Sorry still a little confused. I can get it to display the 8….but are you saying that if I press the accelerator a little “2” should pop up somewhere on the screen to tell me when I’ve hit 2nd gear? Or is it just something I gotta feel for by hitting the accelerator and feeling some short of feeling?

Sorry for all the questions lol

No problem! A "2" will display right alongside the "8". As soon as you hit the "-" button, you should see a "1" displayed alongside the "8" as long as you're in "D". Accelerate and you'll see the "1" change to "2" when you get the RPM's up.

 

[kayla02110]

Sorry one more question, say I run through the fill procecdure but my truck gets hotter than 122deg before I’m able to get under there to open the fill hole to fill.

I obviously shut it off and wait for it to cool down. But once it’s cooled down again to between the 86-122 range….do I have to run through the fill procedure again before refilling, or can I just turn the engine on and fill?