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Jeep Wrangler: 8HP70 ZF 8-Speed Harsh Cold 1-2 Upshift

8HP70 ZF 8-Speed Harsh Cold 1-2 Upshift is a common transmission fault on the Jeep Wrangler on the 2018 onward cars, and we rate it major. Putting it right costs $180 to $2,200 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 24 documented faults on the Jeep Wrangler.

Vehicle
Jeep Wrangler
Years
2018 onward
Fuel
petrol
Gearbox
auto
System
Transmission

This page covers the Jeep Wrangler as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Jeep Wrangler faults24 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Clutch yet. We would rather show none than show a picture of a different part.

What goes wrong

The ZF 8HP70 eight-speed automatic transmission fitted to the JL Wrangler exhibits a pronounced harsh or clunky 1-to-2 upshift during the first few minutes of driving from cold, particularly in ambient temperatures below 15 degrees Celsius. The fault is caused by hydraulic clutch pack engagement pressure being calibrated too aggressively at low ATF temperatures. FCA/Stellantis issued multiple PCM and TCM calibration updates, but a proportion of vehicles continue to exhibit the fault after reprogramming.

What you would notice

  • Firm, jerky, or clunking 1-to-2 gear change in the first 2-5 minutes of cold driving
  • Lurch or driveline shudder felt through the vehicle during low-speed cold upshift
  • Symptom disappears completely once transmission reaches normal operating temperature
  • Condition noticeably worsens in cold winter ambient temperatures

How to check it

Where to look. 8HP70 automatic transmission unit, torque converter and clutch pack assembly

Test drive the vehicle from a fully cold start. Conduct several low-speed 1-to-2 upshifts within the first two minutes and assess shift quality. Request that the dealer verify the current TCM calibration version against the latest Stellantis release. If a workshop inspection is possible: Check for any stored transmission fault codes via scan tool.

Parts involved: Clutch.

What it costs to put right

$180 to $2,200 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

  • “Has the TCM or PCM software been updated to the latest calibration release for the 8-speed transmission?”
  • “Has the transmission fluid been changed or inspected within the service history?”
  • “Has any shift quality complaint been logged and investigated under warranty?”

Now check the Jeep Wrangler you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Jeep Wrangler buyer questions

Is 8hp70 zf 8-speed harsh cold 1-2 upshift serious on a Jeep Wrangler?

We rate it major and common on the Jeep Wrangler. The ZF 8HP70 eight-speed automatic transmission fitted to the JL Wrangler exhibits a pronounced harsh or clunky 1-to-2 upshift during the first few minutes of driving from cold, particularly in ambient temperatures below 15 degrees Celsius. The fault is caused by hydraulic clutch pack engagement pressure being calibrated too aggressively at low ATF temperatures. FCA/Stellantis issued multiple PCM and TCM calibration updates, but a proportion of vehicles continue to exhibit the fault after reprogramming.

How much does it cost to fix on a Jeep Wrangler?

$180 to $2,200 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Jeep Wrangler years are affected?

Our research records this fault on the 2018 onward Jeep Wrangler. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Test drive the vehicle from a fully cold start. Conduct several low-speed 1-to-2 upshifts within the first two minutes and assess shift quality. Request that the dealer verify the current TCM calibration version against the latest Stellantis release. If a workshop inspection is possible: Check for any stored transmission fault codes via scan tool. Look here: 8HP70 automatic transmission unit, torque converter and clutch pack assembly