4L80E vs 46RE: Differences and Which One to Choose

These two four-speed automatics land on the same shopping list constantly: someone is either pulling a tired Chrysler unit out of a 5.9L Ram, Dakota or Durango and wondering whether a GM 4L80E swap is worth the trouble, or they are buying a truck and want to know what is actually bolted under it before they commit to a rebuild. They are both heavy-ish four-speed overdrive automatics from the same era, and they look similar on a spec sheet. They are not the same transmission, and they do not fail the same way.

Here is what actually separates them, what each one breaks, and how to decide which one you should be putting money into.

Quick identification: which one do I have?

The easy tell is the brand of the truck. The 4L80E is GM. Per DieselHub, it is found in 1991-1999 GMC Sierra / Chevrolet Silverado 1500, 2500 and 3500 and Suburban, and 1996-2002 GMC Savana / Chevrolet Express vans. The Novak Guide notes it was introduced in 1991 and stayed in production through the 2009-plus model year, also showing up behind Hummer H1 and G-series van applications.

The 46RE is Chrysler. It is an A518 derivative, which itself is an A727 TorqueFlite with an overdrive tacked on the back. The 46RH was the hydraulically governed version; the 46RE moved governor pressure control over to electronics. GearboxList puts 46RE production at 1997-2003 behind the 5.9L Magnum, in the Dodge Dakota (DN) 1997-2003, Dodge Durango (DN) 1997-2003, Dodge Ram (DR) 1997-2002, Dodge Ram (DT) 2002-2003, and Jeep Grand Cherokee (ZJ) 1997-1998.

Physically the 4L80E is unmistakable: the Novak guide lists it at 26-1/4 inches long with an integrated bellhousing available only in the Chevrolet 90-degree pattern, and a 32-spline output shaft in both 2WD and 4WD versions. That integrated bellhousing is the single biggest reason a 4L80E-into-Mopar swap is a project and not an afternoon.

Gear ratios and torque: the numbers side by side

DieselHub lists the 4L80E ratios as 2.482 first, 1.482 second, 1.00 third, 0.750 fourth, 2.077 reverse. Novak lists the same spread rounded to 2.48 / 1.48 / 1.00 / 0.75 with a 2.07 reverse.

GearboxList gives the 46RE as 2.45 first, 1.45 second, 1.00 third, 0.69 fourth, 2.21 reverse.

First gear is effectively a wash: 2.48 against 2.45. The real difference is at the top. The 46RE overdrive is 0.69 against the 4L80E's 0.750 - roughly eight percent deeper. Run the spread and the 46RE is actually the wider-ratio box: 2.45 divided by 0.69 is about 3.55, while 2.482 divided by 0.750 is about 3.31. If you are cruising a mostly-stock truck at highway speed with a tall-ish axle, the 46RE overdrive is doing more for you.

Torque capacity flips the other way. DieselHub rates the 4L80E at 440 lb-ft (597 N-m) of engine torque, and Novak adds a maximum output torque figure of 885 ft-lbs and a design target of vehicles up to 8000 lbs GVWR. GearboxList rates the 46RE at up to 500 N-m, which is roughly 369 lb-ft. The 4L85E, for reference, steps the GM unit up to 460 lb-ft per DieselHub.

Weight is worth flagging because the two sources disagree: DieselHub lists the 4L80E at 236 lbs dry and 260 lbs with fluid, while Novak lists 254 lbs dry and roughly 268 lbs full. Either way it is a heavy unit. Fluid spec also differs by camp - DieselHub calls for DEXRON VI at approximately 13.5 quarts total capacity in the 4L80E, and GearboxList lists Mopar ATF+4 (MS-9602) at 13.4 liters for the 46RE. Do not cross those two fluids.

What each one actually breaks

This is where the decision usually gets made, because the failure patterns are completely different animals.

4L80E: pressure control at the boost valve

Sonnax describes the classic 4L80E/4L85E complaint as uncontrollable line rise - upward of 500-600 psi - along with high line pressure in Reverse, buzzing noise, and broken direct clutch drums and/or broken cases. The cause is not the drum. Per Sonnax, reverse boost oil enters the torque signal circuit through a wear-created cross leak at the boost valve sleeve, and the high line pressure and buzz come from oil leaking past the aluminum balance plug. In other words, the pump cover bore and boost valve let go, line pressure runs away, and the hard parts pay for it.

That is a bore-wear problem, which means a plain rebuild kit with no attention to the pump cover will do it again. Sonnax's fix is a hardened steel boost valve with over 20 percent wider spools plus an O-ringed sleeve and a replacement balance plug (kit 34200-01K in the O-ring style, or 34200-03K for units with the factory-style sleeve). If you are opening a 4L80E, check that bore before you decide the case cracked for no reason.

46RE: governor pressure control and valve body wear

The 46RE's headline weakness is the electronic governor pressure circuit. GearboxList lists the "centrifugal regulator" and unreliable wiring among its weak points, alongside three other patterns worth knowing: the torque converter clutch wants replacing on a service interval or the solenoids load up with debris, reduced lubrication pressure burns the Direct and Forward clutch packs, and at very high mileage the brake band and reverse drum typically need replacement.

The valve body is the other half of the story. Sonnax's 46RE/46RH/47RE/47RH Vacuum Test Guide maps the critical wear areas and ties each to a symptom you can actually feel from the driver's seat:

• Switch valve - no cooler flow in Park, lockup shudder, converter bushing failure, overheated converter, forward clutch drags in Park, soft TCC apply. Sonnax replacement 22771-09.
• Governor plugs - 1-2 shuttle, 2-3 and 3-2 oversensitive shifts. Sonnax 22771A-01 or 22771A-13, tested together.
• Throttle valve - shift timing concerns, throttle buzz, poor kickdown, late 2-3, oversensitive 3-2. Sonnax 22771-14K.
• Pressure regulator valve - PR buzz, lube failures, reverse slip, converter bushing failure, poor forward and reverse engagement. Sonnax 22771-03K or 22771-04K.
• Line pressure plug and sleeve - poor line pressure control, poor cooler charge at idle. Sonnax 22771A-02K or 22771A-07K.

One 46RE-specific trap before you order anything: Sonnax's 42RE, 46RE, 47RE Valve Body Identification guide warns that you must determine both the pressure sensor type and the pump inlet size. The early pressure sensor has an oval-shaped electrical connector; the late sensor is plastic and rectangular. Sonnax splits the reman valve bodies accordingly - CHR129 for '99-earlier with early sensor and small pump inlet, CHR130 for '99-earlier with early sensor and large pump inlet, CHR131 for '00-later with late sensor and small pump inlet, CHR132 for '00-later with late sensor and large pump inlet. Buying by year alone will get you the wrong part.

The fix: which parts you actually need

If the 46RE is shifting erratically, flaring, or has a wandering shift point rather than slipping under load, start at the governor pressure solenoid and transducer before you pull the pan for a rebuild. That circuit is the number one 46RE electrical complaint and it is a fraction of the work of an overhaul.

Our 46RE governor pressure solenoid kit with sensor covers both halves of that circuit in one shot. The rest of the 46RE and 4L80E electrical parts live in the solenoids collection, including the 4L80E shift solenoid kit for 1991-up units if you are chasing a GM shift-code complaint instead.

If it is slipping under load, burning fluid, or you already found metal in the pan, it is a rebuild - and given what Sonnax says about the 4L80E boost valve bore, plan on addressing pressure control at the same time rather than reusing worn parts.

On the Chrysler side, the 46RE Master Transmission Rebuild Kit for 1998-2002 covers the same ground. Both models, plus every other unit we stock, are in the rebuild kits collection.

Replace while you are in there

Once the unit is out, these are the items that cost almost nothing relative to the labor of going back in:

• Filter and pan gasket - non-negotiable on both units.
• Torque converter - GearboxList specifically calls out the 46RE converter clutch as a service item that, left too long, contaminates the solenoids. A converter with a failing clutch will kill a fresh rebuild.
• 4L80E boost valve and sleeve - per Sonnax, the root cause of runaway line pressure and broken drums and cases. Reusing a worn one repeats the failure.
• 46RE governor pressure solenoid and transducer - both are in the pan and both are wear items on this unit.
• 46RE front and rear bands, and the reverse drum - GearboxList lists the band and reverse drum as high-mileage replacements. Inspect, do not assume.
• Cooler lines flushed or the cooler replaced - debris from the old failure will find its way back.
• Bushings - Sonnax repeatedly ties converter bushing failure to valve body wear on the 46RE family; check them while the case is apart.

Cost and effort framing

A 46RE governor pressure solenoid and transducer replacement is a pan-down job. For most competent DIYers that is an afternoon: drain, drop the pan, swap the solenoid and sensor, new filter and gasket, refill with ATF+4. Call it two to three hours plus fluid, and no special tooling beyond a torque wrench.

A valve body service on the 46RE - vacuum testing bores and dropping in Sonnax valve kits - is a bench job that adds several hours and does require the vacuum test setup Sonnax describes. Shops that do this regularly are fast at it; first-timers should not attempt it blind.

A full rebuild on either unit is a remove-and-replace with a full teardown. Budget the transmission out of the truck, the case fully disassembled, hard parts inspected, and the pump cover addressed on a 4L80E. That is realistically a full weekend for a well-equipped DIYer with a press and a lift, and a multi-day job at a shop. The 4L80E's 236-268 lb mass, depending on which source you trust, means a transmission jack is not optional.

So which one should you choose?

Keep the 46RE if the truck is a stock or mildly modified 5.9L Ram, Dakota, Durango or ZJ Grand Cherokee that is not towing at the edge of its rating. It is already in there, the bellhousing and driveline already match, its 0.69 overdrive is better for cruising than the 4L80E's 0.750, and its failure modes are well documented and mostly serviceable without exotic parts.

Go 4L80E if the torque number is the binding constraint. The 440 lb-ft engine-torque rating DieselHub lists is meaningfully above the 46RE's 500 N-m (roughly 369 lb-ft), and the GM unit's aftermarket support for high-output builds is deeper. Just be honest about the swap: Novak's integrated Chevrolet 90-degree bellhousing means an adapter for anything non-GM, and it is fully electronically controlled, so you need a controller strategy - factory PCM, standalone, or otherwise - before the transmission goes in.

If you already own a GM truck, this is not really a debate; you have a 4L80E and you should build it right. If you own a Mopar, the 46RE deserves a fair diagnosis - governor pressure circuit and valve body first - before you spend swap money.

FAQ

Is the 4L80E stronger than the 46RE?

By published input torque rating, yes. DieselHub rates the 4L80E at 440 lb-ft (597 N-m) of engine torque. GearboxList rates the 46RE at up to 500 N-m, or roughly 369 lb-ft. That is a real gap, though both figures are factory design ratings and neither reflects what a properly built unit will survive.

Will a 4L80E bolt into a Dodge Ram in place of a 46RE?

Not directly. Novak notes the 4L80E has an integrated bellhousing with only the Chevrolet 90-degree engine bolt pattern available, so a non-GM engine requires an adapter. You also inherit a fully PCM-controlled transmission, which means sorting out control before it will shift at all. It is a swap project, not a bolt-in.

Why does my 46RE shift erratically at random speeds?

Start with the governor pressure circuit. GearboxList lists the governor and its wiring among the 46RE's known weak points, and Sonnax's vacuum test guide additionally ties worn governor plugs to 1-2 shuttle and oversensitive 2-3 and 3-2 shifts. Check the solenoid and transducer first, then vacuum-test the valve body bores before condemning the whole unit.

Related reading

If you are comparing the GM unit against the diesel Chrysler four-speed instead, see 4L80E vs 47RE: differences and which one to choose.

Sources

• GM 4L80E, 4L85E Transmission Specs & Ratios - DieselHub
• The Novak Guide to the GM 4L80E Automatic Transmission
• Sonnax Boost Valve Kit 34200-01K (GM 4L80-E, 4L85-E)
• Sonnax: Chrysler 42RE, 46RE, 47RE Valve Body Identification
• Sonnax: Chrysler 46RE, 46RH, 47RE, 47RH Vacuum Test Guide
• Gearbox Chrysler 46RE: specifications, gear ratios, oil - GearboxList