ZF8HP Dodge Charger Slipping: Causes and Fix

A Charger that "slips" on the eight-speed can be four different things: a low fluid level, a TCM calibration that holds shifts too long or blocks the top gears, adaptations that never relearned after a repair, or a clutch pack that has actually let go. FCA published bulletins on all four for the LD Charger, and only one of them, the 850RE D clutch bulletin, says the fix is a hard part. The order you check them in decides whether this is a one-hour job or a transmission out of the car.

This guide stays on slip, flare and lost-gear complaints on 2012-up Chargers with an eight-speed. For bumps, clunks, false codes and the shifter recall, see our ZF8HP Dodge Charger common problems guide.

Recommended ZF 8HP parts for a slipping Charger

An 8HP45 master rebuild kit for V6 845RE/8HP45 cars with a burnt pack, an 8HP70 master rebuild kit for Hemi and SRT cars, and a full service fill of ZF LifeguardFluid 8 to set the level correctly. 850RE D clutch jobs use the FCA kit in the bulletin. Match the part to your sales code. Secure checkout on our own site.

8HP45 Master Rebuild Kit

$340.99View part

8HP70 8HP75 Transmission Master Rebuild Kit BMW Jeep Dodge

$463.99View part

ZF Lifeguardfluid 8 ATF, 7-Liter Service Fill for 8HP70

$223.99View part

First, Which Eight-Speed Is in the Car

FCA gates every Charger transmission bulletin by sales code and build date, so get the build sheet before anything else. Bulletin 21-012-14 Rev. B, the drive learn bulletin, lists the 2012-2015 LD Charger with four first-generation units: the 845RE (DFL), 8HP45 (DFG), 8HP70 (DFK) and 8HP90 (DFE). The second-generation 850RE (DFT) is the one in bulletin 21-009-25 Rev. A, which lists the 2020-2023 LD Charger.

A 2012-2014 Hemi Charger is a five-speed, not one of these. Gen 1 and Gen 2 clutch packs, valve bodies and rebuild kits do not interchange, so the sales code also decides what you order.

What "Slipping" Means on This Transmission

The ZF eight-speed builds eight forward gears and reverse from four planetary sets, two brakes (A and B) and three clutches (C, D and E). Sonnax's "A New Path for ZF" lays out the apply chart, and every gear uses exactly three of the five elements:

That makes the road test the diagnosis. Write down which gears slip and which hold, then find the element every bad gear shares. A Charger that pulls hard through 3rd, flares into 4th and will not back up is pointing at D. One that slips in 1st, 2nd and reverse but holds from 3rd through 6th is pointing at A.

Separate a true slip from a flare. A true slip is the engine speed climbing in a gear that should be locked, under steady load. A flare is a short RPM rise during the shift that settles once the next gear takes. On the scan tool, log commanded gear, input speed and output speed. If the input-to-output ratio sags during the shift and then matches the commanded gear, the pack holds once it is on and the apply is late or soft: level, adaptations or pressure. If the ratio never matches under load, the pack is not holding.

One more pattern to rule out: a car that revs high on the highway and never gets to 7th or 8th. Owners call that slipping. It often is not, as the software section below shows.

Check 1: Set the Fluid Level the ZF Way

Low oil shows up as slip before anything else. The pump draws air on hard launches, turns and braking, and line pressure drops right when a clutch is trying to apply. The Charger has no dipstick, so the level is set at the fill plug inside a temperature window. ZF Service Information 50130 gives the procedure, and you need a scan tool reading transmission oil temperature:

1. Car level on the lift, in Park, parking brake on, electrical loads off, no limp mode active.
2. Bring the oil to 30-50 C. Hold 2,000 rpm for 30 seconds to fill the converter, then return to idle.
3. Select P, R and D, then hold D1 and D2 for about 10 seconds each. Confirm the oil is still inside 30-50 C.
4. Pull the fill plug, add fluid until it runs out, wait for single drops, and reinstall the plug: M18 x 1.5 at 35 Nm or M22 x 1.5 at 30 Nm, depending on which plug is in the case.

ZF warns that an underfill damages the transmission, and that a level set above 50 C reads full but will be low once the oil cools. Write down how much it took. If a Charger that flares on hard right turns or after a stop took most of a liter, that is the diagnosis, and the next job is finding the leak at the pan, cooler lines or the mechatronic sleeve (see our 8HP sleeve leak guide).

FCA's Charger bulletins call for Mopar ZF 8&9 Speed ATF, 68218925AB; the 21-009-25 Rev. A parts list allows 10 of them on a D clutch job. ZF's own product is LifeguardFluid 8, and its data sheet recommends a change at 150,000 km (about 93,000 miles), sooner under severe service. No additives.

Check 2: Software That Feels Like Slip

Three Charger bulletins describe complaints that drivers call slipping, and all three are TCM flashes:

• High RPM and no 7th or 8th (2015 V6): bulletin 21-041-17 (September 12, 2017) covers 2015 3.6L Chargers, DFL and DFG, where a flash-over-the-air radio update can leave the shift points defaulted high. The transmission shifts at high RPM and 7th and 8th may be blocked. It feels like the car is slipping on the highway. The packs are fine.
• P0734 with nothing wrong (2015 V6): bulletin 21-023-15 Rev. B covers LD cars with the 845RE built March 9 to June 26, 2015, and 8HP45 cars built on or before June 27, 2015. It describes an erroneous MIL with P0734 (gear 4 shift incorrect ratio), P1DCD and P1B13. A ratio code reads like a slipping clutch on paper. On these cars it is a reflash.
• Hanging or delayed upshifts (2016): bulletin 21-023-16 covers 2016 V6 Chargers built on or before May 31, 2016, and 21-026-16 covers 5.7L 8HP70 cars built on or before June 6, 2016. The complaint is an upshift that hangs when braking downhill, after hard acceleration, or when the driver lifts quickly. A hang followed by a late shift is easy to mistake for a flare.

Every one of these flashes carries the same FCA rule: a battery charger on so the voltage stays above 13.2 volts and does not climb past 13.5, and restart the flash if it aborts. Check the calibration before you condemn a pack on a ratio code.

Check 3: Adaptations That Never Relearned

This catches a lot of Chargers after a battery job, a TCM replacement or a repair somewhere else. Bulletin 21-012-14 Rev. B explains that the 845RE, 8HP45, 8HP70 and 8HP90 store learned values for every clutch in "adaptation memory cells": a fill time in milliseconds and a fill pressure in millibar or psi, each with a counter showing how many times it has updated. Those cells are zero on every new or replaced transmission, on a replaced TCM, and whenever they are cleared with a scan tool, and FCA says shift quality may not meet the customer's expectations until they relearn.

The bulletin gives numbers to check. The filling counter should ideally be at least 12 (6 on the 8HP70/90) and the fast filling counter at least 4 (2 on the 8HP70/90). A counter at zero means that cell has never updated. So when a Charger comes in flaring after recent work, pull the A through E counters first. If they are near zero, the transmission has not learned yet, and clearing them again will not help.

The learn itself: oil at least 30 C (86 F), then shift 1st through 8th on light, steady throttle, rate every upshift, downshift and the reverse engagement from 1 to 10, and run the adaptation drive procedure on anything poor. The same bulletin sets two rules for builders: after an overhaul the cells must be cleared unless the mechatronic itself was replaced, and the drive learn is required whenever the transmission or mechatronic is repaired or replaced.

Check 4: The 850RE D Clutch Bulletin (2020-2023 Charger)

On a DFT Charger this is the slip complaint that matters. FCA bulletin 21-009-25 Rev. A (February 1, 2025), "D Clutch Repair," lists the 2020-2023 LD Charger alongside the Challenger, 300, Ram 1500, Durango, Grand Cherokee and Wrangler, all with the 850RE. The entry rule is strict: the MIL must be on with one or more of:

• P0733-00: gear 3 shift incorrect ratio
• P1DA8-00: incorrect gear ratio, clutch A, B or D defective
• P1D92-00: incorrect gear ratio, clutch 4 defective

Owners may also say it slips when shifting, will not move in reverse, or will not shift higher than 3rd. Check that against the apply chart: D is applied in 4th through 8th and reverse, so a failing D clutch removes exactly those ranges and leaves 1st through 3rd working.

The Charger-specific details from the bulletin:

• Labor op 21-00-64-92, D clutch inspect and replace on LA/LD/LX: 6.7 hours, plus 0.9 hours on AWD Chargers and 1.0 hour for the adaptation procedure.
• Output shaft D clutch repair kit: 68239499AD for AWD LA/LD/LX, 68676892AB for RWD LA/LD/LX.
• Fluid: up to ten 68218925AB.

The procedure removes the converter and works through the output end, and the TCM adaptation is mandatory afterward. The bulletin's first step is the useful one outside a dealer: "Are DTCs P0733, P1DA8 or P1D92 present?" If not, it does not apply, and a 2016 845RE with the same feel is a different diagnosis.

When a Gen 1 Pack Really Is Burnt

If the level is right, the calibration is current, the counters have learned and the scan data still shows a ratio that will not hold under load, it is a mechanical slip. On the first-generation units, Sonnax calls "A" clutch burnup a chronic problem on the ZF8, 845RE and 850RE, and traces it to the OE backing plate flexing during apply, which wears the pack unevenly and builds heat. Its fix is a thicker, stiffer plate: 35577-45 for the 8HP45, 8HP50, 8HP51, 845RE and 850RE, and 35577-70 for the 8HP55, 8HP70 and 8HP75. A slips in 1st, 2nd, 7th, 8th and reverse, so a V6 Charger that slips off the line and in reverse but holds in the middle gears fits that pattern.

A pan full of friction material and slip in several unrelated gears means a rebuild. Put the upgraded A plate in while it is apart, clear the adaptation cells, and run the drive learn before the car goes back. Sonnax's webinar is also worth a look for the electrical side: the 8HP45/70 solenoids run 5 to 6 ohms depending on temperature, and EDS-7 is line pressure, which is the solenoid to check when every element feels soft at once.

Quick Fix Map

Frequently Asked Questions

Why is my Dodge Charger transmission slipping?

The usual causes on the Charger eight-speed are a low fluid level from a leak, TCM software, adaptations that have not relearned after a repair or TCM reset, and on 2020-2023 V6 cars with the 850RE a failing D clutch. Set the level at the fill plug with the oil at 30-50 C first. Then note which gears slip, because every gear uses three of five clutches and the shared one is usually the culprit.

Is there a TSB for a slipping Charger 8-speed?

Yes. FCA bulletin 21-009-25 Rev. A covers 2020-2023 LD Chargers with the 850RE (sales code DFT). It requires a MIL with P0733, P1DA8 or P1D92, lists slipping on shifts, no reverse and no shift above 3rd as complaints, and the repair is a D clutch replacement at 6.7 hours plus 0.9 for AWD and 1.0 for the adaptation procedure.

Why does my 2015 Charger rev high and never shift into 7th or 8th?

FCA bulletin 21-041-17 covers 2015 3.6L Chargers where a flash-over-the-air radio update can leave the transmission shift points defaulted high, so it shifts at high RPM and 7th and 8th may be blocked. It feels like slipping, but the fix is a TCM reflash, not clutches.

Why does my Charger shift badly after a battery or transmission repair?

The 845RE, 8HP45, 8HP70 and 8HP90 store learned fill time and fill pressure for every clutch, and those values reset to zero when the transmission or TCM is replaced or the cells are cleared. FCA bulletin 21-012-14 Rev. B says shift quality may not meet expectations until they relearn. Check the filling counters, then run the adaptation drive learn instead of clearing them again.