Also known as: nsg370, nsg-370, ng3, mercedes nsg370
The six-speed manual in the Jeep Wrangler TJ and JK, the Liberty, and the Chrysler Crossfire.
It is a Mercedes-Benz gearbox, which is what the DaimlerChrysler years left behind and what nothing on a Wrangler tells its owner. So the useful literature is split across two worlds — Jeep forums and Mercedes parts catalogues — and a search in only one finds half of it.
Its recurring complaint is noise rather than failure. These are known for a gear rattle at idle in neutral with the clutch out, which is normal for the design and not a fault; and for a whine in fifth and sixth that owners find alarming and which is usually the gearbox behaving as built. The tell for a genuine bearing problem is that it rises with road speed in every gear, not only in the tall ones.
Where it genuinely wears it is the shift tower and the synchros for second and third, producing a crunch on a fast cold change. A crunch in every gear is the clutch not releasing — hydraulic, outside the gearbox, and much cheaper.
It takes a specific fluid. These want a synthetic manual-transmission oil to the Chrysler specification; a conventional gear oil makes the change notchy when cold and is often mistaken for synchro wear.
Cars fitted with this gearbox
5 generations. Only where a source names the model and the generation together — a gearbox is documented as a product far more often than as a fitment, so this list is deliberately shorter than the truth.
Chrysler
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about NSG370.