8hp70 shifting issue.

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TC Retired

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In hotter climates, change the fluid, or colder climates when you get a hard shift in the lower gears... But especially hotter climates.
 

RamRBest

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Mine did some clunking every once in a while for years 3 to 7 but hasn happened lately.
 

jh90731

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FWIW - I had my pan and fluid changed by a local shop at around 70k miles. I purchased online a factory Mopar pan and filter combo and 7 qrts of the ZF 8-speed fluid. The shop said they replaced about 6.5 qrts of the 7qrts I gave them. I immediately noticed a slightly different shift pattern after this, nothing drastic just different. After about 20k miles I finally jacked up the rear so the transmission body was level and crawled under. Following the instructions I downloaded from the ZF website I checked the fluid level. It turns out they had overfilled the trans by almost a full qrt. Draining some out to the correct level helped but I still wasn’t happy with how it felt. About 10k miles ago I crawled back under and used an electric suction pump I purchased off Amazon to suck out fluid via the fill hole. I was able to suck out about 4 qrts and replaced them with Pentosin’s ZF 8spd fluid purchased from Rock Auto. Just changing 4 qrts I noticed a huge improvement in the shifting. I’m getting ready to crawl back under and repeat the same process - suck out 4 qrts and replace with the Pentosin. We tow a small travel trailer through the Sierra Nevada’s so once I get about 8 more qrts of the Pentosin changed into it I’m planning to repeat this process at least once a year.

Curious to know if anyone else uses the Pentosin.
 

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RASelkirk

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Of all things (2018) RAM, the one single thing I HATE, HATE, HATE is the shifting of my trans. Part throttle is fine, but WOT shifts, worse than rubber bands or hamsters running in a cage, are totally for crap. I am loath to spend $1200 for a new ECM, unlock, and tune just to fix it. Totally sucks to get on it and suffer from this crappy flaring issue...

Russ
 

Wild one

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Of all things (2018) RAM, the one single thing I HATE, HATE, HATE is the shifting of my trans. Part throttle is fine, but WOT shifts, worse than rubber bands or hamsters running in a cage, are totally for crap. I am loath to spend $1200 for a new ECM, unlock, and tune just to fix it. Totally sucks to get on it and suffer from this crappy flaring issue...

Russ
You might be experiencing torque management if it's happening at WOT. Watch this short little video till the end where the car is on the track,and listen to the 2 -3 shift,my grandmother can double clutch a straight cut transmission faster then the car makes the 2-3 shift,lol.

 

ThunderMug95

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Im 3 weeks post-trans pan and fluid change at 80k. My trans is happy. It was happy beforehand though. Its tuned and it shifts great. Went with a PPE pan, but I was lucky. Found it sealed/NIB on Marketplace. I need to drain and fill again though.
 

RASelkirk

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You might be experiencing torque management if it's happening at WOT. Watch this short little video till the end where the car is on the track,and listen to the 2 -3 shift,my grandmother can double clutch a straight cut transmission faster then the car makes the 2-3 shift,lol.


It's even worse when you get off a full throttle run mid-way. The trans gets so confused it doesn't know whether to shift up, down, or hold. Kinda sounds like a ricer with a full-on engine...

Russ
 

TC Retired

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FWIW - I had my pan and fluid changed by a local shop at around 70k miles. I purchased online a factory Mopar pan and filter combo and 7 qrts of the ZF 8-speed fluid. The shop said they replaced about 6.5 qrts of the 7qrts I gave them. I immediately noticed a slightly different shift pattern after this, nothing drastic just different. After about 20k miles I finally jacked up the rear so the transmission body was level and crawled under. Following the instructions I downloaded from the ZF website I checked the fluid level. It turns out they had overfilled the trans by almost a full qrt. Draining some out to the correct level helped but I still wasn’t happy with how it felt. About 10k miles ago I crawled back under and used an electric suction pump I purchased off Amazon to suck out fluid via the fill hole. I was able to suck out about 4 qrts and replaced them with Pentosin’s ZF 8spd fluid purchased from Rock Auto. Just changing 4 qrts I noticed a huge improvement in the shifting. I’m getting ready to crawl back under and repeat the same process - suck out 4 qrts and replace with the Pentosin. We tow a small travel trailer through the Sierra Nevada’s so once I get about 8 more qrts of the Pentosin changed into it I’m planning to repeat this process at least once a year.

Curious to know if anyone else uses the Pentosin.

They used the drain/fill process. It is very easy to over/under fill. Better process is to use a clean pan and once drained - verify how much fluid you have and only add that amount of new fluid!
Also, if your Tranny was acting up, repeat the process after a few hundred miles so that you have mostly new fluid. And yes, keep repeating the process regularly.

Side note the Aisin Transmission on 2015 3500 - they want you to change the fluid every 30k miles.
 

joesstripclub

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How do you do it for $60? The Pan and filter combo is more than that by itself! Unless your doing the cheap no name ebay brand pan.
Yep cheap no name ebay pan and filter. Actually got the one for the v6 as it was only $30. I did have to buy a new gasket for it, so maybe $70 with a jug of maxlife as well. Been running for 20k miles with no issues. Drain plug even sealed after using it when I had to change the gasket.
 

blackbetty14

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Yep cheap no name ebay pan and filter. Actually got the one for the v6 as it was only $30. I did have to buy a new gasket for it, so maybe $70 with a jug of maxlife as well. Been running for 20k miles with no issues. Drain plug even sealed after using it when I had to change the gasket.
Was the gasket defective or junk? I thought they wouldn't work great given the low low price of them.
 

chrisbh17

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Re the firm "first shift of the day":

Using AlfaOBD, Ive monitored various TCM parameters, and for that first shift it allows for more "slip" RPM, up to 100RPM vs 50 that it normally allows. Im assuming there is a reason for it, but its definitely not "accidentally" slipping.

Also read if you roll slowly through P R N D before taking off, it helps purge air out of the clutches faster, which should lead to less firm shifts for the first mile or so.
 

joesstripclub

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Re the firm "first shift of the day":

Using AlfaOBD, Ive monitored various TCM parameters, and for that first shift it allows for more "slip" RPM, up to 100RPM vs 50 that it normally allows. Im assuming there is a reason for it, but its definitely not "accidentally" slipping.

Also read if you roll slowly through P R N D before taking off, it helps purge air out of the clutches faster, which should lead to less firm shifts for the first mile or so.
Interesting discovery. Sometimes I will shift the truck into N and D for a few seconds before I take off and it seems to help with the first shift flare up. I dont think my truck has ever done it a second time though. I also notice when I leave work, which is all downhill through the site until you make it to the exit, the truck will often stay in 1st unless I give it any gas, but if I keep rolling out without stopping it will hold first til 3k or 4k rpm before it shifts to second even with very light throttle. Not sure if it's seeing it as a weird input or its weird programming.
 

joesstripclub

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Was the gasket defective or junk? I thought they wouldn't work great given the low low price of them.
I had a small leak from it so decided to replace it with OEM. Found out that the V6 and V8 pans have different alignment holes for the gasket though, so had to snip the pin off since I bought a V8 gasket.
 
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DtheBC

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@blackbetty14 I have $250 in my pan and zf fluid. The reason is a friend traded his ram before he used them and let me have them cheap. I dont think thats brutal and the process is what it is. Though a dip stick would be better.
 
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DtheBC

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I will try the D-N-R-D trick when/if it flares up again. Its so intermittent and when it does it its only one time out of the gate till it cools all day or sets over night. It hasnt done this since I posted a few days ago and before that it was in October. It just goes a while then surprises me.
 

jh90731

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I agree, the process is what it is and a dipstick would make things easier. But now that I have figured out what I need to get the transmission level (floor jack, jack stands, wooden platforms for the jackstands, chocking the front wheels), using an electric suction pump and where to purchase approved fluid at a better price than the dealership or ZF, the process won't be difficult the next time.
@blackbetty14 I have $250 in my pan and zf fluid. The reason is a friend traded his ram before he used them and let me have them cheap. I dont think thats brutal and the process is what it is. Though a dip stick would be better.
 

Brent 1955

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I have read on many of the tranny posts and not seen anyone mention what mine is doing. When cold every once in a while I get a rough kick in the pants shift when it shifts up through the first few gears. Its when accelerating lightly on flat ground. It seems to shift 1-2-3-2-3 then on up. When it does this the truck bucks and gives a pretty good kick in the pants. After this one time it works perfectly till it cools off. If I get on it pretty good it want do this, nor when warm. I have not cel or mil lights. When it does this weird shift I see the tach go up and down with the bucking when this occurs. I see some posts on shudder but this is more of a bucking hard up down up shift feeling and only in the first few gears. Has anyone experienced something like this?
do you warm your tranny up before taking off? You have a thermostat on your tranny coolant lines. So chances are it isn't your tranny at all but the torque converter. I have that problem if i don't let my oil run to the torque converter before I take off, but I have a flow thru thermostat. What temperature does it happen mostly in. Mine happens in the winter months more than summer.
 

blackbetty14

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@blackbetty14 I have $250 in my pan and zf fluid. The reason is a friend traded his ram before he used them and let me have them cheap. I dont think thats brutal and the process is what it is. Though a dip stick would be better.
Well I'm used to $70 empty case new build fluid fills on older transmissions with filter... so $250 for a pan drop and some fluid is $$ lol. Think 700r4, TH350, 2004R, C6 filters are $16 ish and fluid is cheap!
 
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DtheBC

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Things have changed for sure. I wonder if there is all that much difference between a good synthetic red transmission fluid and the unicorn tear zf fluid. Sure are a lot of folks using valvoline maxlife in these zf trannys with no issues.
 

TheEnder

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If your tagline is correct, you don't have an 8HP series transmission. The 8HP was not available in Rams until very late 2013, and not with the 4.7 motor.

Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 83507 miles
I have a Chrysler with the 845RE.
 
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