ZF 8HP 8 Speed Automatic Transmission

See inside the incredible ZF 8-Speed Transmission
TIMELINE:
0:00 Introduction
1:20 The parts and powerflow dilemma
3:00 The input shaft
3:15 The arrangement of the four planetary gear sets
4:30 The remote mounted oil pump and front cover
5:20 The stator support shaft and the function of the "A" Brake clutch
6:00 The "A" clutch hub
6:15 The Simpson P1, P2 sun gear
6:48 The P1 Annulus gear
7:08 The function of the "B" Brake clutch
7:22 The P1 planet carrier
8:48 The input shaft and the P2 carrier
12:02 The P2 annulus gear and P3 sun gear
12:18 The P3 planet carrier
12:36 the P3 annulus gear
13:48 The "E" clutch hub
14:10 the "C" clutch hub
15:15 The P4 sun gear to P3 annulus gear shell
17:00 The "D" clutch to P3 planet carrier shell and precautions to avoid damage
19:19 The P4 planet carrier and output shaft
20:16 The P4 annulus gear
20:24 The P4 annulus to P1 carrier shell
22:05 The parking gear
22:50 The transmission case and the "B" Brake clutch
23:30 Transmission identification
23:50 the oil fill and oil level checking plug
24:00 the oil pan and built-in filter
24:18 oil level checking instructions
25:10 The valve body
25:55 Summary
ABOUT US:
Weber State University (WSU) - Automotive Technology Department - Transmission Lab. This episode demonstrates the components and operation of the ZF 8HP 8-speed automatic transmission used in select Chrysler, Jeep, Dodge, HellCat, and other brands of vehicles.
This transmission uses 4 planetary gear sets, 3 clutches, and 2 brake clutches.
www.weber.edu/automotive
This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see www.weber.edu/automotive/J_Kel...
DONATE TO OUR DEPARTMENT
Please consider a donation to the Department of Automotive Technology at Weber State University here: advancement.weber.edu/Automotive

[@ademc8872]

Hands down the best transmission in the world right now. Amazing shift quality and speed especially if you map it with xhp.

[@WeberAuto]

Thanks for watching

[@richardprice5978]

so cool it doesn't need sprague's or bands to work a weaker part in turbo 400's and 727 transmission as the the 70's big power car's ended up eating them like candy 🍬 yes the aftermarket is backing this transmission well enough to get used as swap's and or hot rod'ed/modified from OEM/dealership's configurations

[@scottchila7284]

ZF 8 speed has a high failure rate

[@anonimous2451]

@@scottchila7284 Show me the Data. We want FACTS son.

[@zyzzyx3160]

Too bad vehicle manufacturers rate it as lifetime fluid transmission. Tere should be a provision to make fluid changes easier. I burned the crap out of my hand when doing so.

[@wardmacfarlan6306]

What a blessing to live in an age when we have the expertise of men like professor Kelly's literally at our fingertips! Fascinating......that was a very fast 26.5 minutes; seemed a lot shorter.

[@m2useinu]

Archaeologists finding one of these transmissions a thousand years from now will think it was a timepiece

[@keyboarddancers7751]

This gearbox is an engineering triumph because so many car manufacturers now use it.

[@hau5muzeek]

the way the zf8 shifts with performance software is insane

[@jonsnell4751]

An excellent video as always. It does look like rocket science in action but it is very simple in practice. Thank you for your efforts, very interestingly shown.

[@racingdaily3674]

Wow, this is some of the best educational content I've seen on KZbin. Well done and thank you!

[@andyburnett8012]

A fascinating demonstration! I'm in awe at your knowledge and skills with transmissions, it amazes me how these things are designed, very clever engineers indeed 🤓

[@steventaylor6294]

Thank you for that clear explanation. You're truly a great teacher.

[@AlexandreOliveiraAlex]

Amazing explanation, this kind of complex technology fascinate me... awesome mechanics engineering... thank you so much John...

[@mrj8908]

Awesome Presentation on the ZF-8 transmission 👍 Thanks well done

[@Trades46]

I've been following you for a long time & each time BARELY grasping how the transaxle operates. I thought nothing will top that 9HP transaxle in your last video, but those ZF boffins actually managed to top even that insanity. Now I'm reminded why I'm a Sociology & not an Engineering major. Kudos & thanks for this in-depth tour of this engineering masterpiece.

[@WeberAuto]

+Trades46 Thank you very much!

[@getthejobdone6883]

Thank you so much for your vids. I'm doing a individual project according to the ZF transmission to come up with an idea to make this even more efficient. So those video's seriously helped me get to know the transmission a bit more!

[@WeberAuto]

+GetThe JobDone Thank you! I am glad it was helpful

[@nandiito]

What an awesome transmission and what an awesome instructor. Made a great class out of a video.

[@WeberAuto]

Thank you very much!

[@warrenh3515]

I had only a vague understanding of how transmissions work, now I have a better, but not full, understanding. Thanks for your demonstrating.

[@mattbernasconi9654]

Great video, thank you for the breakdown and sharing knowledge on this mechanical marvel!!

[@WeberAuto]

Thank you!

[@solidSchmaltz]

Fascinating! I love your videos, thank you!

[@WeberAuto]

+Scott Simon Thank you!

[@kaktusjack1033]

Mr.Kelly your lectures are awesome and this one is no exception. You are a really good lecturer. Thank You very much for this and the other lectures.

[@WeberAuto]

+Kaktus Jack Thank you!

[@towers2000]

Amazing transmission! Even more amazing explanation on such a complex machine, thanks!

[@WeberAuto]

Glad you liked it!

[@Robsbrd99]

Thank you very much for the help.

[@majidsiddiqui2906]

Great video. What a woderful transmission. Its a work of art.

[@MayurShinde01]

Really Amazing to see this design...Incredible effort @john 😊

[@amoliveira7357]

Excellent!!!))) One of the best videos I have seen...

[@1gr8oil]

Once again a very good explanation on Transmissions.

[@WeberAuto]

Thank you!

[@hammerhead6537]

Great video! As usual very well explained, thank you.

[@WeberAuto]

Thank you!

[@siwachira9662]

Let's appreciate this marvel of engineering. Thanks John for the great video.

[@WeberAuto]

Thanks for watching!

[@AlltimeFN]

I have a 2013 awd Charger that i needed the transmission replaced in. I loved the video and plan on taking the transmission home with me when they are done so I can tare it done to she this in person! Amazing design!!!

[@BoZmD]

Amazing explanation!

[@MrPatdeeee]

As always John, you did a great job. I commend your teaching ability. It is truly exemplary dear person. I will continue to strive to learn HOW it works. But due to its complexity, that may be a long time. Keep up the excellent work John.

[@WeberAuto]

+pat dee Thank you very much!

[@padilla2435]

Thank you very valuable information. Makes me want to attend your classes.

[@Autotransvn]

I love Automatic Transmission Car. Thank you Sir.

[@WeberAuto]

Thank you!

[@hagopk.3165]

thank you john for good job .

[@WeberAuto]

+crist john Thank you!

[@brevinainslie6357]

Great video- I love this transmission. Extremely smooth in my Ram 1500.

[@lawsonhollenbaugh3626]

WOW, THIS IS DEFINITELY A MIND NUMBING, COMPLEX TRANSMISSION, THANK YOU FOR SHARING THIS FANTASTIC VIDEO.!

[@WeberAuto]

Thank you very much

[@scottfromengland2303]

Great video & very intuitive 👍🏻 keep up the good work mate

[@WeberAuto]

Thank you

[@anatoliyzhukov960]

Incredible video! Helped me a lot to understand the gearsets' design of this transmission. Thanks from Russia!

[@WeberAuto]

Thank you!

[@Xatger]

I bought a BMW520D with the 8 hp ZF and your breakdown and explanation of how wonderful this gearbox work is first class . Will . Dublin Ireland . Thank you Sit

[@WeberAuto]

Thank you!

[@sebamcb813]

THANKS FOR UR WORK

[@buddjay000]

Had to pause this video several times just to rack my head around exactly what was going on with power flow! Incredible engineering and explanation!

[@WeberAuto]

Thank you!

[@rafihussain]

Thanks. Nicely explained.

[@alexanderorozco661]

Thank you. For the class.

[@sundhukumar]

Wow! Amazing demonstration of torque converter gear box Kudos sir🎉

[@hv9356]

Thank you for the video and taking the time do it. It's awesome to see how far the auto industry has come. 400hp with an 8 speed. My Ram feels like a corvette, it's so quick.

[@WeberAuto]

Thank you!

[@glennortega9430]

I was looking this up as the new 2019 Toyota Camry I purchased, has a 8 speed automatic transmission. I stayed and watched the whole video. Impressive. Thanks.

[@MartinofVegas]

your camry likely is rocking Aisin 8 speed which is probably most reliable in the world! Not ZF

[@senhorateu4365]

Parabéns MESTRE. Extraordinário Nota MIL.

[@jackhayward4605]

Excellent presentation sir!

[@WeberAuto]

Glad you liked it!

[@myfastcars]

Wow! I am totally impressed with your knowledge and ability to educate. I am also wowed by this ecomplex beast. Excellent knowledge transfer! Bill

[@jimrusch22]

Thanks for the great video. When I was growing up , I studied 2 speed Powerglides, Ford C4’s and Chrysler Torqueflights. All these are very simple and easy to understand. Boy, have the times changed. I have the ZF 8 speed in our Grand Cherokee. Indeed it is a remarkable design. Shifts as smooth as butter.

[@WeberAuto]

Thanks for your feedback, we have 9 and 10 speeds now

[@jimbuford4147]

Good demonstration. Thanks

[@WeberAuto]

+Jim Buford Thank you!

[@aSASa45454]

I could listen to this guy talk about anything all day

[@jeffbendertheenforcer5834]

I was a big torqueflite guy back in the day. Great video.

[@WeberAuto]

Thank you

[@patricnukee]

thanks for the knowledge!

[@scottweatherman3266]

Awesome video instruction. If ZF makes as good an automatic as their manual transmissions, this should be one excellent transmission.

[@WeberAuto]

+Scott Weatherman Thank you!

[@billgateskilledmyuncle23]

Then they made the 9 speed aaaaaand.....meh...

[@FrenchValleyAirport]

Excellent transmission

[@WeberAuto]

Thanks for your feedback

[@Chengz0r]

Because my dad recently got a new car with this 8-spd transmission, I became curious about auto transmissions in general. Let's just say that small curiousity costed me many many hours of deep diving into internet before I could find anything that was enough in-depth and not too focused on math. With this video I'm finally starting to understand. So thanks!

[@WeberAuto]

+André Smith Thank you!

[@karihardarson1234]

Master teacher! Thank you.

[@WeberAuto]

Thank you!

[@dil6969]

Amazing transmission. I've driven several cars with these, most notable being a Giulia Quadrifoglio. It's buttery smooth when you're driving normally and crazy fast and responsive in race mode. The people that design these are on another level of intelligence.

[@WeberAuto]

Thanks for watching

[@EdcarImports]

Congratulations, perfect explanation, thanks to share with us

[@WeberAuto]

Thank you

[@bluebull1985]

awesome video - THANK YOU!

[@raymondkyabagu34]

That's great our master of automatic gearbox

[@mk1cortinatony395]

What an amazing tutor!

[@daveyJ213]

Good grief! This is amazing! Who designs this stuff and who can figure out how it works? Rhetorical questions, but still, to a non-mechanic like myself it's totally astounding. So cool. This video is a great example of the good part of the Internet. Anything you want to learn about, you can experts like this to education and explain. Thanks for posting!

[@dvobgo92]

I own a 2021 Jeep Wrangler Rubicon and it uses the 2nd generation ZF8 and it is arguably one of the smoothest and best performing transmissions currently on the market. The ones in non-V8 FCA (Chrysler) vehicles are actually made right here in the states since ZF gave FCA the license to produce the 8HP50 under their trademarked name Torqueflite 8 - 850RE. However, for all their diesel and V8 vehicles, FCA still buys the 8HP75 (the second generation of the 8HP70 shown in your great video) from ZF in Germany. This is the first time I have seen an expert actually demonstrate all the internal gearing and mechanisms of the ZF8, and in such great detail. Thank you for your work professor.

[@WeberAuto]

Thank you very much

[@lucasduck95]

wonderful video about a wonderful transmission

[@JACB006]

Thank you ... very informative. Good video.

[@WeberAuto]

Thank you!

[@RCFiddyOne]

Great info. Thanks for sharing.

[@WeberAuto]

+RCFiddyOne Thank you!

[@dwightgoad6281]

I have a Ram 1500, and I may have issues with my transmission. I still think the 8 speed design is awsome! This is great information, and a great video.

[@WeberAuto]

Thank you for your feedback!

[@victorsanchez1983]

I hear is bad in the ram 2500 too. That’s why I’m doing a little research 🤔

[@ericfaley9019]

Great info. When Chrysler introduced this transmission series I took a 2 day training class of disassembly and reassembly. The instructor stressed do not repeat do not lay the transmission on its side and drag the parts out onto the bench. Use the square box stand used for the g56 trans. Stand it up at all time. Dragging the parts out and falling onto the bench will distort the steel drums. A guy in my class drug the parts out onto the bench. Damaged a drum. That class has been changed to a 1 day service class. Only component we at the dealership can replace is valve body and external seals.

[@WeberAuto]

Thanks for your feedback! Some people are not ready for detailed transmission work, it can take years of training and a lot of patience.

[@geojor]

another good one...

[@Dreson45]

Well done sir! Excellent video. Another engineering triumph is the electrified version of this transmission. ZF have some wizards designing these things.

[@WeberAuto]

Thanks for watching

[@josepha9313]

Hi great video which made me research Weber State; I didn't know that auto tech was taught at the 4-year level. Thanks.

[@WeberAuto]

Thank you!

[@marth6271]

Thanks for the careful explanation. Right now my brane is above normal operating temperature.

[@chekelley6861]

Aliens design this stuff!! Another great video!

[@WeberAuto]

+Che Kelley I agree, thanks for watching!

[@18081987]

You got my respect sir!

[@WeberAuto]

Thank you!

[@fayobam_mech_tronics]

Don't know why I enjoyed the video this much 😁

[@hagopk.3165]

master thank you for you best job ,

[@WeberAuto]

Thank you!

[@tt-rs1457]

Very very good explaination ! I have this gearbox in my Challenger.....here in germany.

[@WeberAuto]

Thanks for your feedback

[@ehud59]

Vi have in Sweden. You are a good teacher.🙂

[@WeberAuto]

Thank you!

[@mrpoopybutthole6314]

I loved this demonstration. I thought I had my head grasped around it until you mentioned reverse and I have no clue how they achieved it.

[@LetzHaveALook]

I understood 3% of what you said. But it's fascinating to watch the engineering of this transmission design. Great detailed description 👌

[@ellomirza]

This is why I love KZbin. If this ever made it to tv back in the day, for it to be palatable to the general public it would have to be edited down to something that would offer no educational value. Sometimes you just feel like knowing EVERYTHING about something :-)

[@iulianbudusan8707]

That s a proper mechanic hand cleaning procedure!!!!

[@brianschott8162]

Amazing piece of engineering marvel modern day transmissions!

[@hardroad8236]

Very good job at describing the internals of the ZF8 speed. I understood everything that you said. Very Complex And mathematical design genius to come up with such A efficient transmission. It looks like it wouldn't be that hard to work on No clutch plates to deal with all ran on planetary And Simpson gears. And I can't believe the certain housings that inner connect For the shifting of the transmission. I have the same transmission in my 2017 ram 1500 And I love it incredibly smooth. It always seems to find the right gear to be in. Anyway I would love to see you explain the 10 speed transmission that ford and Chevy designers came up with. Thanks again for the video It definitely helped me understand completely. wish I can take one of your classes. Can't wait for further videos keep up the good work I'm sure there are many many people like myself That need your intelligence In this field. Thanks again

[@WeberAuto]

Thank you! I have a Ford 10-Speed in the lab right now.

[@hardroad8236]

can't wait to see you break down the 10-speed I'll be watching thanks again.

[@RandiEriko]

nice explanation.

[@WeberAuto]

Thank you

[@yurryadityapratama7767]

Satisfying to see the way he attach the gear set

[@bilibiliism]

I bought a car with this tranmission recently. So I decided to watch some video to figure out how it works only to fullfill my curioisity. I watched this video from the first second to the last. And I realised I didnt understant single bit of it. Technology nowadays... It must be designed by some crazy scientist!

[@WeberAuto]

+bilibiliism I agree!, Thanks for watching!

[@sultanabran1]

they're called Germans

[@user-oz1vs8tl3j]

Those crazy scientistes are Germans! And may God bless them! I have the same transmission in my BMW f 34 GT 2015 ! Great transmission just wooow!!

[@sbalak]

As usual the credit goes to the Germans.

[@viki6or]

The transmission is very simple as the mister said. All gear sets interact with each other to provide 8 gear ratios. To develop this gear sets they actually used a supercomputer to calculate the rate at which these gears sets are moving. Mechanically its a very simple and repairable transmission if attended by a specialist of course.

[@stevekoehn1675]

Thats a beautiful thing. The math shouldn't be that complicated. Thanks for showing

[@sdn1528]

What a masterpiece of engineering

[@davidpeterson6147]

excellent video.

[@WeberAuto]

+David Peterson Thank you!

[@JohnBrown-vn2qw]

+WeberAuto wow! it even confuses a pro. makes me wonder what kind of people think up this stuff

[@stainfels7176]

Hi, great video! Greetings from an german engineer who understands the first time the german engineering in this part of his car ;-)

[@WeberAuto]

Thank you!

[@r.p.8133]

Best Gearbox ever built!

[@RRaucina]

Beautiful engineering and metal work. And still absolutely unfathomable after your take down. Odd idea to change the entire pan for a filter, but a miracle that it has a means to check the level without a 20 page guide and a thermometer

[@Davidoff8503]

Great lesson ! I’ve got Jaguar XF with this transmission and was wondering how it looks inside and how it works.

[@uswwt]

Great video. This transmission is indeed a dream, when it's working perfectly. Mine started to slip a bit in 150K miles. Oil never changed. BMW claims that no change is needed, LOL. So indeed they completely changed the seals and connection of the valve body to transmission. I can't find any info about the bridge seal, tube seals etc found in the 6HP version. I am tempted to change oil on mine and want to make sure all those easy to replace rubbers are changed at the same time.

[@RudolfKlusal]

I am in the development of 8HP/9HP/7DT/8DT and these transmission are really marvleous 🙂

[@adamzhang2461]

I am new to the automotive industry as a transmission controls engineer. I couldn't express how excited I was when I saw your videos on the actual demonstration of these transmissions that I deal with everyday. THANK YOU for all the hard work you shared with us! But I would like to expect if by any chance you can talk about the hydraulics part of the transmission in the future.

[@WeberAuto]

+Adam Zhang Thank you for your feedback! I would like to do hydraulics at some time in the future.

[@ScriptureConsolidated]

i wouldve loved to see the electric assist drive installed with it. awesome demo either way!

[@celtichongy]

Thanks to John at Weber Auto, excellent presentation material as usual. Interesting design of the outer drive drums - reminds me of a giant Starrett hole saw cutter, except this application has drive teeth rather than cutting teeth. Those outer drums could have a useful afterlife life when salvaged as some sort of colanders or deep fat friers in a fast food kitchen! (-;

[@WeberAuto]

+celtichongy Thanks for the nice comments and feedback! They do look like giant colanders!

[@scottofford3061]

I trust these videos are used by your students. Great learning tool.

[@WeberAuto]

Yes, I make them for my students, but I also share them with everyone else as a recruiting tool

[@teacherm96]

Thanks for the information.

[@WeberAuto]

You are welcome!

[@teacherm96]

I have a 2013 Grand Cherokee SRT 5 speed how strong is the Transmission? Thanks

[@WeberAuto]

It is a great transmission, very few problems.