ZF8HP70 fails 1>2 shift under WOT

[LilSick]

and those are the mods ^^^ there in yer sig???

[james1595]

and those are the mods ^^^ there in yer sig???

yes

[james1595]

Anything new on this or am i still dead in the water?

[shak3r]

Anything new on this or am i still dead in the water?

Sucks you're still having issues. Have you considering installing a 1320-spec converter? Just sounds like something is wrong w/ your stock converter. How many miles u have on the tranny?

[james1595]

I thought about it, just converters are so expensive for these cars. $1200 for the convertor, plus a new filter, fluid, and labor. As for miles about 37k . I have not been to the track yet, but I believe i have possibly found a fix. Most people take away torque reduction, ive had to add it, but now i might have to much, and am scaling it down

[Enthusiastic]

I thought about it, just converters are so expensive for these cars. $1200 for the convertor, plus a new filter, fluid, and labor. As for miles about 37k . I have not been to the track yet, but I believe i have possibly found a fix. Most people take away torque reduction, ive had to add it, but now i might have to much, and am scaling it down

Any update on a Fix?

My 8HP70 $3,600 trans rebuild was more for longevity with the Raybestos frictions and Raybestos Kolene treated steels and valve body Sonnax Zip Kit (Shift Kit) to handle the additional power now at about 680+ RWHP on pump gas and 13lbs boost. I was told this upgrade should handle up to 900HP. Unfortunately the upgrade does not come with a billet steel E clutch for that price or new solenoids but the solenoids were supposed to be tested.

The Raybestos clutch/friction materials and the valve body Sonnax Zip Kit (Shift Kit) materials are as follows.
https://www.raybestospowertrain.com/...packs/rgpz-018
https://www.raybestospowertrain.com/...packs/stmzf19k
https://www.sonnax.com/parts/4590-zip-kit
https://www.alltranz.co.nz/media/115...structions.pdf

I witnessed the teardown. The clutches were definitely burned. It was scary to see how thin and light the transmission internal and externally splined "aluminum" hubs/shell are. The rebuild seemed to solve my WOT 1-2 shift problem but then the problem came back after a few days and it happened 50% of the time. Lighter throttle may work but that takes me back to the original problem.

With my current power, now when the shift fails at WOT with the 6,700RPM rev limit activating limp mode, the sudden belt torque tension, tensioner limit, and belt stretch expands the belt faster than the tensioner can respond during the sudden acceleration and deceleration. This results in eating my heavy duty Gates HD 6 rib green belts like candy. This also snaps the crappy stock and aftermarket belt tensioners (not designed for supercharger load) :-)

I upgraded the tensioner with a $79 Ford Motorcraft BT-92 (7R3Z6B209AA) tensioner with twice the tension, movement, and durability of the stock MOPAR part. It also works on 8 rib systems. It is used on the Ford supercharged Shelby including the 760HP Ford Mustang GT 500 Shelby. You will need an adaptor plate for the Dodge Durango. HHP sells the adaptor plate with the tensioner. This is a cheaper Ford OEM solution to the 9x cost of an ARS tensioner. Now if I go into limp mode it will just snap the belt (unfortunately, confirmed). If the tensioner did fail, replacement is $79, almost cheaper than the belt.

I am still hoping a tune will fix and I do not have to resort to changing my Circle D 2800-3000 stall for the MOPAR OEM performance 1320 with the 2350 stall speed converter. The cam operating range is 2,100-7,100 with a duration of 270. This is ideal for my current 2800-3000 RPM stall converter. The 2350 would not be the best match.

To complicate things, I did notice in my scanner that the valve body solenoid current, on one of the solenoids, when activated during the 1-2 shift, was half the current of the others. A slow or sticky activating solenoid? Maybe this was not detected during the trans build? Still hoping a tune will fix.

Notes on 1-2 Shift and Solenoids:
The 1 >2 shift is a transition that adds "RS2" (Solenoid) engagement to the RS1 already engaged and a single Clutch transition from Clutch "C" to a single Clutch "E". I believe mechanically, the fluid line from the pump is longest for the E clutch, which may make it more troublesome. The valve body shift kit is supposed to help with this shift delay. I did have an alternator failure that caused a voltage surge to 16V and one overheat condition with the previous engine. This condition could possibly contribute to a solenoid coil issue, even though the solenoids are supposed to be very reliable, especially with only 60,000 miles and 3 fluid changes.

Note: All the shifts above Gear #2 have two or more clutches engaged. For example, Gear #6 at 1:1 ratio (dyno testing gear) has the most clutches engaged with three clutches C, D, E.

[james1595]

Any update on a Fix?

My 8HP70 $3,600 trans rebuild was more for longevity with the Raybestos frictions and Raybestos Kolene treated steels and valve body Sonnax Zip Kit (Shift Kit) to handle the additional power now at about 680+ RWHP on pump gas and 13lbs boost. I was told this upgrade should handle up to 900HP. Unfortunately the upgrade does not come with a billet steel E clutch for that price or new solenoids but the solenoids were supposed to be tested.

The Raybestos clutch/friction materials and the valve body Sonnax Zip Kit (Shift Kit) materials are as follows.
https://www.raybestospowertrain.com/...packs/rgpz-018
https://www.raybestospowertrain.com/...packs/stmzf19k
https://www.sonnax.com/parts/4590-zip-kit
https://www.alltranz.co.nz/media/115...structions.pdf

I witnessed the teardown. The clutches were definitely burned. It was scary to see how thin and light the transmission internal and externally splined "aluminum" hubs/shell are. The rebuild seemed to solve my WOT 1-2 shift problem but then the problem came back after a few days and it happened 50% of the time. Lighter throttle may work but that takes me back to the original problem.

With my current power, now when the shift fails at WOT with the 6,700RPM rev limit activating limp mode, the sudden belt torque tension, tensioner limit, and belt stretch expands the belt faster than the tensioner can respond during the sudden acceleration and deceleration. This results in eating my heavy duty Gates HD 6 rib green belts like candy. This also snaps the crappy stock and aftermarket belt tensioners (not designed for supercharger load) :-)

I upgraded the tensioner with a $79 Ford Motorcraft BT-92 (7R3Z6B209AA) tensioner with twice the tension, movement, and durability of the stock MOPAR part. It also works on 8 rib systems. It is used on the Ford supercharged Shelby including the 760HP Ford Mustang GT 500 Shelby. You will need an adaptor plate for the Dodge Durango. HHP sells the adaptor plate with the tensioner. This is a cheaper Ford OEM solution to the 9x cost of an ARS tensioner. Now if I go into limp mode it will just snap the belt (unfortunately, confirmed). If the tensioner did fail, replacement is $79, almost cheaper than the belt.

I am still hoping a tune will fix and I do not have to resort to changing my Circle D 2800-3000 stall for the MOPAR OEM performance 1320 with the 2350 stall speed converter.

To complicate things, I did notice in my scanner that the valve body solenoid current, on one of the solenoids, when activated during the 1-2 shift, was half the current of the others. A slow or sticky activating solenoid? Maybe this was not detected during the trans build? Still hoping a tune will fix.

Notes on 1-2 Shift and Solenoids:
The 1 >2 shift is a transition that adds "RS2" (Solenoid) engagement to the RS1 already engaged and a single Clutch transition from Clutch "C" to a single Clutch "E". I believe mechanically, the fluid line from the pump is longest for the E clutch, which may make it more troublesome. The valve body shift kit is supposed to help with this shift delay. I did have an alternator failure that caused a voltage surge to 16V and one overheat condition with the previous engine. This condition could possibly contribute to a solenoid coil issue, even though the solenoids are supposed to be very reliable, especially with only 60,000 miles and 3 fluid changes.

Note: All the shifts above Gear #2 have two or more clutches engaged. For example, Gear #6 at 1:1 ratio (dyno testing gear) has the most clutches engaged with three clutches C, D, E.

I have not logged the solinoid activation, but i will now. But as of now no fix. I am still running the factory 5.7 convertor though

[LilSick]

Anything new on this or am i still dead in the water?

the only way to tune this area (1-2 shift) is by referring to logs (good logs) (as in required pid's and not created on a laggy lap top) while slicked down at a track that hooks

[Enthusiastic]

I have not logged the solinoid activation, but i will now. But as of now no fix. I am still running the factory 5.7 convertor though

So sorry it did not work. You get an E for effort or E for E clutch, the one that engages for the first time in 2nd gear . Sorry bad joke. Laughing is better than crying.

My supercharged 5.7 setup with the stock 5.7 torque converter and stock 8HP70 worked fine with 560WHP before the engine failed. The issue started with the new forged 6.4 setup with the same supercharger, surprisingly the same horsepower, and with the same stock 8HP70. I later lowered the trans fluid operating temp to 130 degrees but the problem still existed.

When the trans was rebuilt, it only temporarily fixed the problem so something is marginal. It would be much easier if there was a complete failure.

Again the common change is still the Circle D 3000 stall converter and tune. I was told to change the converter to a higher stall for the cam and higher horsepower. On the chance there is a solenoid issue, I will go back and try to find my old log of the solenoid that was half the current on the scanner tool.

In addition, I recently added another 120+ horsepower for the other 6 gears That probably does not help any for the 1-2. It is crazy how track cars can put down over 1,200 HP to those sticky tracks with the right tires. They probably don't even need 1st gear and just skip that one.

[Enthusiastic]

I have not logged the solinoid activation, but i will now. But as of now no fix. I am still running the factory 5.7 convertor though

I can definitely see how a sticky track changes everything regarding the tune and much easier to break stuff. However, if you smoke the tires on a safe street, can you get a successful 1>2 shift? Mine only needs to be tuned for a successful street shift as a first step. I am not ready for the track.

[Enthusiastic]

I have not logged the solinoid activation, but i will now. But as of now no fix. I am still running the factory 5.7 convertor though

I could not find my log, data, or playback showing commanded gear #2. I only had one in park as illustrated. Same with the shift solenoid valves, the commanded gear is not showing. I will need to relog those to confirm. However, as you can see below Shift Solenoid B Current does not seem correct at 360.8 mA.

You would think a solenoid is either full on or off. Assuming that the solenoid voltages are all the same, and the amount of force necessary to activate them are all the same, then you would think that all of the coil resistance and induced current would be the same. If true, then a drastically different reading may indicate a bad solenoid coil or a bad supply or ground current resister, if they are used. I do not have a schematic. The voltage supply of the solenoid valve is stable at 13.24V for a 24 second sample. If the solenoid sensed current path should be 850mA, then the resister (if used) and coil total path resistance should be about 15.5 OHMS.

Solenoid B Current at 360 mA would indicate that the current path resistance is much higher at 40 OHMS, implying bad resistor, solenoid, loose or badly crimped wire connector, oxidized or loose solenoid terminal, pinched or damaged wire. At almost 1/3 the current, this may indicate that the force used to activate the solenoid valve may be 1/3 of the other solenoid valves which could barely be enough for it to activate at certain pressures and maybe very slow or not completely activating or closing with higher pressure or mechanical resistance. At least that is my theory. Based upon this, I would say that in this case it may have been wise to request changing all of the solenoids when rebuilding a transmission. I will need to talk to a transmission expert to verify if this makes any sense. Finding one in my area is challenging.

!!Solenoid-Voltage_8HP70_Enthusiast.jpg!!Solenoid-B_Current_8HP70_Enthusiast.jpg

[LilSick]

I can definitely see how a sticky track changes everything regarding the tune. 2 if you smoke the tires on a safe street, can you get a successful 1>2 shift?

Spinning on the street all sorts of things can happen. Combine how low the low gear reduction is with a street tire and a dirty street - the trans can run itself over

Or it can complete the 1-2 shift and then nick the rev limiter anyways from spin

https://youtube.com/shorts/SqAvZnYo5...3O8AVYbQtNn8vK

[Enthusiastic]

Spinning on the street all sorts of things can happen. Combine how low the low gear reduction is with a street tire and a dirty street - the trans can run itself over

Or it can complete the 1-2 shift and then nick the rev limiter anyways from spin

https://youtube.com/shorts/SqAvZnYo5...3O8AVYbQtNn8vK

The trans can run over itself. ROTFLOL
Your ride sounds awesome, no nappy time for the kids.

Mine sounds like a sewing machine compared to yours:
https://www.youtube.com/watch?v=JiHT...GApFE8&index=1

[james1595]

the only way to tune this area (1-2 shift) is by referring to logs (good logs) (as in required pid's and not created on a laggy lap top) while slicked down at a track that hooks

I have many times. Im now going to be logging almost every trans perameter i can log. But when you look at the logs, it sumply just didnt try to shift. However, ive messed with the torque managment and think i found what was needed. Hopefully anyway

[LilSick]

The trans can run over itself.

Your ride sounds awesome,

Mine sounds like a sewing machine compared to yours:
https://www.youtube.com/watch?v=JiHT...GApFE8&index=1

thanks!

[LilSick]

for the trans to shift from low to 2nd valve for E needs to be open and valve for C needs to be closed

both those are normally open valves

[Enthusiastic]

for the trans to shift from low to 2nd valve for E needs to be open and valve for C needs to be closed

both those are normally open valves

Found this a while back. Can't find the source
[UPDATE 1/20/2024] - Apparently these are the clutch diagrams and not solenoid. I think captured from a video.
HP70_Gear-1.JPG
HP70_Gear-2.JPG

[LilSick]

valves

[Enthusiastic]

valves

Thanks!

Apparently, the solenoids are actually more complicated than I thought. They are not just on/off fluid switches. They are normally open or normally closed variable force PWM solenoids (pulse-width-modulated) that control the fluid pressure for each hydraulic circuit. Cool!

This probably provides an incredible amount of control when it works right. I believe the TCM pulses the 13V solenoids, sync to ground (in TCM/PCM), so the current will be variable based upon duty cycle.
It is better to state the solenoid is energized (on) or not (de-energized, off) as their is a mix of normally open or closed. Also keep in mind that when energized, it is variable how much because of PWM.

Not sure if 1>2 shift is a 1st flare or delayed 2nd causing engine max rev limp. Hard to tell by feel or sound as the attempted shift cycle is so fast from first gear. Hopefully the log captured this. If the issue is not the tune and is mechanical, I would not suspect the fluid, fluid paths, or clutches recently upgraded. Also, the valve body zip kit (shift kit) mods are supposed to help reduce the normal "E" clutch delays if installed properly. The normal "E" clutch delay is because the fluid run distance is longest from the fluid pump for the "E" clutch.

Regarding fluids - I tried the branded Chrysler genuine MOPAR OEM ZF 68157995AA (ZF Lifeguard 8), Amsoil ZF compatible version - OE Fuel-Efficient Synthetic (OTLTP-EA/2.5-Gal.), Valvoline MaxLife full synthetic fluid, and currently I am using "Liqui Moly Top Tec ATF 1800 synthetic fluid" installed by the trans builder.

It is clear depending on usage, your fluid should be changed before 50k miles per ZF. Vehicle OEM "Lifetime fluid" is not correct when ZF (the trans manufacturer) recommends fluid changes every 50K miles or less in heavy-duty use. However, after the OEM vehicle warranty, usually 50K miles (coincidence maybe?), all of the compliant “multipurpose” full synthetic fluids should be ok as long as they support the replacement of ZF branded Lifeguardfluid 6, Lifeguardfluid 8, Lifeguardfluid 9, and meet the TE-ML11A, 11B, 14 specs. I have tons of information on this but it really boils down to the specification requirements and the highly profitable branded reseller agreements enforced by the vehicle OEM warranty requirements.

I am running cooler than normal operating temp which could affect viscosity and may slightly affect fluid velocity and pressure but the issue existed before the lower temps. Fluid brand and viscosity probably would have more impact than the cooler temp. I think there may be some tune temperature settings that may limit torque but this could be offset it necessary.

Solenoids Energized (Excluding Park):
1st = A, B, D, E
2nd = A, B, C, D
1-2 Shift Change = C (on), E (off); solenoid picture layout illustration below (Figure 51), White Color Solenoids C = #4, E = #5
Note: "Clutches Applied" Chart for 1-2 Shift is opposite, C (off), E (on, applied)

Clutch Application:
1st = ABC
2nd = ABE
1-2 Shift Change = C (off), E (on)


I wonder how the important "E" clutch pressure for second gear is modulated when the fluid flow is already highest on the normally open circuit with the solenoid "off". As long as the E solenoid is off and ABCD are energized when second gear is commanded, the ABE clutches should be engaged. I assume the transition is probably very important from clutches ABC to ABE on how the pressures are modulated for the on/off transition and clutch engagement. The AB braking clutches stay engaged during the transition but the rotating C clutch transitions to rotating E. Then it would seem that the Line Pressure Solenoid (LPS) and Torque Converter Clutch solenoid (TCC) needs to be very fast in modulating the pressure and clutch friction for the WOT torque. Maybe the timing of releasing/reducing pressure C while engaging/increasing E then balancing the line pressure without burning up everything or decreasing durability. So goes my current hypothesis :-)
Here is some great info:

HP70_Clutch-Solenoid_01-03.png
HP70_Clutch-Solenoid_02-03.png
HP70_Clutch-Solenoid_03-03.png
HP70_Clutch-Solenoid_04.png

[Enthusiastic]

for the trans to shift from low to 2nd valve for E needs to be open and valve for C needs to be closed

both those are normally open valves

Yes, correct for flow.

That means 2nd gear for "energized" solenoids:
E = off, open (to engage E clutch); low or no current
C = on, closed (to disengage C clutch); higher current depending on PWM duty cycle
Note: Solenoids ABD will still be on (energized) so ABCD should all be reading some energized current for 2nd gear and the TCC and LPS may have some current depending on PWM at idle.

Not sure what the PWM duty cycle would be fully transitioned to 2nd gear and what that current would be. Scanner tool may tell me this at least at idle with the brake on. The paddle shifter will allow 2nd gear at idle to test. It is possible the lower current solenoid I saw, was the LPS or TCC current at low idle torque with different PWM, which would make sense. I need to check it again.

The automatic trans calibration procedure has to be done whenever there are changes like a rebuild including replacement of the clutches, valve body, or other modifications. Normally the trans builder/installer will perform this but it was not done successfully in my case. It shifted very badly. I ran the calibration and that totally resolved the issue. The trans temp needs to be at least 130 degrees for the calibration to perform. I did not do a recalibration after the latest engine tune that added another 120+ HP with the smaller Whipple pulley.