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MY TRANSMISSION REPAIR 8hp90

Speedy!

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It's complicated LOL. Most of it is in those posts I linked and some of the stuff I explained earlier. I think now I see why we don't see more information on it. Each setting can have an impact on another. I've got some trans tunes written up and gonna do some testing this weekend.

The fact that HPT gets laggy when data logging some of the transmission pids doesn't help. ZHC said he has the exact same problem and has been on HPT to fix it for a couple years.
 


Confuzed1

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Guys to be honest these transmissions are so well built that depending on your power output and how far you push them you may never need one
Well, some of you guys/gals are pushing your cars to the limits on power output... Great post and informative!!
 


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hellno

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Thread Starter #443
It's complicated LOL. Most of it is in those posts I linked and some of the stuff I explained earlier. I think now I see why we don't see more information on it. Each setting can have an impact on another. I've got some trans tunes written up and gonna do some testing this weekend.

The fact that HPT gets laggy when data logging some of the transmission pids doesn't help. ZHC said he has the exact same problem and has been on HPT to fix it for a couple years.
Translation of speedys reply in terms so some of us will be able to comprehend
( hellno your a fjjjcjjking redneck and you will never understand so just trust me ) 😂😂😂
 


OP
hellno

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Thread Starter #444
I NEED TO GET BACK TO THE GYM .WARNING NOT SUITABLE FOR KIDS ,WUSSIES OR THOSE EASILY OFFENDED ,CONTAINS STONG CONTENT AND LANGUAGE

 


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I NEED TO GET BACK TO THE GYM .WARNING NOT SUITABLE FOR KIDS ,WUSSIES OR THOSE EASILY OFFENDED ,CONTAINS STONG CONTENT AND LANGUAGE

Like a surgeon...
 


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I am shocked by the size of this thing, It looks like something out of a big truck! LOL. any numbers on what this thing weighs?
 


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hellno

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Thread Starter #447
I am shocked by the size of this thing, It looks like something out of a big truck! LOL. any numbers on what this thing weighs?
I REFUSE TO PICK THAT HEAVY ASS THING UP AGAIN AND WEIGHT IT LOL
 


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hellno

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Thread Starter #448
Here’s some pics
I marked the places to air test the clutch packs also 2A5674DE-A80A-46C7-87D7-68216CD02803.jpeg 0F06185A-3B69-4EA4-9D2E-842CC1BC1357.jpeg
 


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Speedy!

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Let me run the car some and get some logs before I start telling people how it's done LOL. This time tomorrow my trans could be on it's way to @hellno because I burned it up :eek:

I think I'm close, but what's throwing me off is comparing a Demon to a Redeye trans tune. There's quite a bit different, and some by A LOT. I would have expected them to be closer. It also "looks" like some of the Demon Crate changes were done quick and dirty, like almost they were at the track and grabbed some cells in the tune and just changed them at WOT rather than blending them like we normally see in a calibration.
 


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Thread Starter #451
Trans is back in the car just waiting on Valvebody solenoids and we will install it hopefully Monday
 


Linda's Hell Cat

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OMG
 


OP
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Thread Starter #453

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OP
hellno

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Thread Starter #455
i think Linda’s thinking your a machine! On a roll....
I ONLY WISH ID HAD ALL PARTS ON HAND FOR IT I COULD OF HAD THE TRANSMISSION PULLED OUT ,REBUILT AND REINSTALLED THE NEXT MORINING:(
 


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I ONLY WISH ID HAD ALL PARTS ON HAND FOR IT I COULD OF HAD THE TRANSMISSION PULLED OUT ,REBUILT AND REINSTALLED THE NEXT MORINING:(
Nice work @hellno , can't wait to see results at track !
 


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hellno

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Thread Starter #457
I GOT A CALL FROM A GUY TODAY OUT OF ARKANSAS ON A JEEP TRACKHAWK ,CURT REFERRED HIM TO ME TO PUT SOME BOLT ON PARTS ON IT ,IM HOPING HE COMES COULD BE A START TO THE PERFORMANCE UPGRADES IM GOING TO START ADVERTISING THAT WE DO FOR NEXT YEAR
 


OP
hellno

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Thread Starter #458
Nice work @hellno , can't wait to see results at track !
THANKS@MEANCAT ,IM PRETTY POSITIVE ALL SHOULD GO WELL BUT UNTIL I GET IT STARTED AND DRIVE IT I WONT ACTUALLY KNOW ,FROM WHAT IM HEARING FROM CURT THE TRANS ARE HAVING ISSUES GETTING THEM TO SHIFT AFTER REBUILD SOMETIMES ,I PERSONALLY BELIEV THAT IT PROBABLY LIES SOMEWHERE IN THE VALVEBODY OR SOLENOIDS ,THE THING THAT CONCERNS ME ON MINE IS THE CLUTCH PACK CLEARANCE , I KMOW I HAVE THEM SET TO FACTORY SPECS BUT WITH THE ADDED CLUTCHES THE CONCERN IS THE RELEASE OF THE PACK WHEN ANOTHER IS COMMANDED ON BECAUSE OF THE POSSIBLY OF THE CLUTCHES DRAGGING ,MY UNDERSTANDING OF THE WAY THE SHIFTING IS CONTROLLED THE COMPUTER SHOULD BE ABLE TO ADJUST FOR IT ,BUT IF I DO HAVE A CONCERN ILL HAVE TO PULL IT OUT AND THEN I WILL ADJUST THE CLEARANCE FOR THE ADDED CLUTCHES ,I THINK IF IT HAS A PROBLEM WITH THE CLEARANCE IT WILL SHOW UP AT WOT BECAUSE THAT WILL BE WHEN THE THE PROCESS OF ONE RELEASING AND THE OTHER APPLYING WILL BE THE FASTEST SHIFT
 


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Pretty sure those HC ZF8 transmissions are built in Mexico https://www.zf.com/mobile/en/compan...de/north_america/mexico_locations/mexico.html). Germans can engineer things all they want, but if you don't follow the specs this is what you get. I'd be willing to be that other high-end (and not just over priced) luxury cars that get the ZF 8s are more tightly built.

EDIT - NM, looks like they are assembled in the US:

Chrysler Group LLC initially received the 8HP 8-speed automatic transmissions from the ZF plant in Saarbrucken, Germany. By 2013, in parallel with Chrysler Group, ZF had set up a new transmission production plant in Gray Court, South Carolina.[7] ZF Friedrichshafen and Chrysler Group have reached a supply and license agreement for the 8HP. Chrysler Group is licensed to produce the 8HP at the company’s Kokomo Transmission Plant and the Kokomo Casting plant, production began in 2013. This transmission is marketed by Chrysler under their own brand name, the Torqueflite 8.[8][9]

2nd generation 8HP products were released starting in 2014. Efficiency improvements over the original design include a wider ratio spread of 7.8:1, reduced drag torque from the shift elements, reduction in required oil pump pressure, and broadened use of the coasting and start-stop systems.[10] ZF estimated fuel economy improvement over 1st generation 8HP kits to be 3%. Refinements were also made with respect to vibration.

3rd generation 8HP products were released starting in 2018. Major improvements are total spread of 8.6 and a fuel economy improvement of 2.5% compared to the 2nd generation. There are several options in maximum torque available, also the gearbox is available with mild hybrid and plug in hybrid options: With 15 kW and 200 NM supporting boosting and recuperation in combination with 48 Volt technology up to 90 kw and 250 NM for usage with higher voltage. [11]
The 3rd gen trans sound more complicated than the 2nd gen. Does that make the 2nd gen less susceptible to problems?
 


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I ONLY WISH ID HAD ALL PARTS ON HAND FOR IT I COULD OF HAD THE TRANSMISSION PULLED OUT ,REBUILT AND REINSTALLED THE NEXT MORINING:(
You could always keep spare parts on the shelf and don’t forget a new spare valve body and tested solenoids. You may need them.
 




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