700R4 vs 46RE: Differences, Strength, and Which One to Choose

Two four-speed overdrive automatics, two completely different families, and one question that keeps coming up: if you are choosing between a GM 700R4 and a Chrysler 46RE, which one actually belongs behind your engine? The honest answer is that they are rarely direct competitors. One is a GM longitudinal overdrive unit that has been the default hot-rod swap for forty years. The other is the electronic evolution of a Chrysler truck transmission that lives almost exclusively behind Dodge and Jeep drivetrains. Where the comparison matters is when you are buying a used truck, planning a rebuild budget, or deciding whether the unit you already have is worth saving.

Here is what separates them mechanically, what each one breaks, and how to decide.

The short version

The 700R4 is a GM Turbo-Hydramatic unit introduced in 1982. Sonnax notes in its 700-R4 build guide that GM renamed the unit to 4L60 in 1989, roughly eight years after launch, and that 1993 was the last year for the 4L60 (700-R4) in most models before the electronically controlled 4L60-E took over. That single fact resolves most of the confusion around these transmissions: a 700R4 and a 4L60 are the same transmission with two names.

The 46RE is the electronically governed member of the Chrysler A518 family. Moveras describes it plainly as "the electronic version of the 46RH." Transmission Repair Cost Guide places its introduction in 1996 and notes the giveaway at the case: the older hydraulic 46RH uses a three-pin connector, while the 46RE carries an eight-pin connector to feed its added electronics.

Gear ratios and physical specs

The ratio spread is where the two units diverge most for a driver.

• 700R4 (per DieselHub): 1st 3.059:1, 2nd 1.625:1, 3rd 1.00:1, 4th 0.696:1, Reverse 2.294:1. Cast aluminum case, roughly 200 lbs dry, DEXRON VI, 8.8 to 11.4 quart capacity depending on application.
• 46RE (per Transmission Repair Cost Guide): 1st 2.45:1, 2nd 1.45:1, 3rd 1.00:1, 4th 0.69:1, Reverse 2.35:1. Moveras lists ATF+4 at a 10-quart fill.

That 3.059 first gear is the 700R4 signature. Sonnax calls out the steep first gear as one of the unit's core benefits, getting heavy vehicles moving without a numerically deep rear axle, while the 0.696 overdrive drops cruise RPM. The 46RE 2.45 first is far more conventional truck gearing, with a similarly deep 0.69 overdrive on the back end. If you are adding overdrive to a classic that currently has a three-speed and a tall axle ratio, the 700R4 first gear does more for you off the line.

Length matters if you are measuring for a swap. Transmission Repair Cost Guide puts the 46RE at about 38 inches overall, roughly three inches longer than the A727 it descended from, with about 24-7/8 inches from the bellhousing flange to the mount.

Control strategy: the real difference

Neither of these is a fully computer-controlled transmission, and that surprises people.

The 700R4 uses a cast iron valve body with a throttle valve cable and a mechanical governor determining shift points, per Sonnax. There is no shift solenoid deciding when it upshifts. The TV cable is not a kickdown cable and its adjustment is not optional: it sets line pressure. Get it wrong and the transmission either shifts early and slips or shifts late and bangs.

The 46RE moved governor control into the electronics. It replaced the 46RH hydraulic governor with a governor pressure solenoid and a governor pressure sensor that the powertrain controller uses to command shift timing. But it kept a mechanical throttle valve. The Sonnax 46RE unit listing still shows symptoms including throttle buzz, poor kickdown, and difficulty in adjusting shift timing with TV linkage, which confirms the throttle valve is still in the circuit and still a diagnostic suspect.

So: the 700R4 is fully mechanical in its decision-making. The 46RE is a hybrid, mechanical throttle pressure plus electronic governor pressure. Neither responds to tuning the way a 4L60-E does.

What each one actually breaks

700R4 failure pattern. The Sonnax 4L60 (700-R4) unit page reads like a list of the same three complaints: 3-4 clutch burned, 2-4 band burned, and low line rise. The root cause chain is documented on the Sonnax throttle valve plunger kit page: the steel TV plunger continuously reciprocates inside the aluminum TV plunger sleeve and wears it. That wear lets throttle valve feed oil leak past the plunger and exhaust, producing poor line rise and no detent downshifts. Sonnax adds that the OE spring is weak, which "can result in low line rise, insufficient throttle pressure and, ultimately, 3-4 clutch failure." Low throttle pressure is not a separate problem from burnt 3-4 clutches. It is the cause of them.

46RE failure pattern. The Sonnax 46RE symptom list is dominated by servo, band, and converter-circuit items: burnt Reverse band, rear servo piston sticking or breakage, Reverse servo piston plug breakage and wear, overdrive roller clutch failure, no line rise during TCC apply in 4th, lockup shudder, and TCC slip under load. The Chrysler pattern is a soft or lost Reverse and a torque converter clutch that will not hold, rather than the GM unit's burnt overdrive clutch pack.

Diagnosis before you decide

If the unit is already in the vehicle, diagnose before you buy anything.

1. Check fluid level and condition on a level surface at operating temperature. Burnt fluid on a 700R4 usually means the 3-4 clutch. Burnt fluid on a 46RE more often points at the Reverse band or the converter clutch.
2. Confirm the fluid is correct. Moveras specifies ATF+4 for the 46RE. Chrysler units are unforgiving about the wrong fluid, particularly for converter clutch shudder. DieselHub lists DEXRON VI for the 700R4.
3. 700R4: verify TV cable adjustment first. Before condemning anything internal, confirm the cable geometry and full-travel adjustment. A misadjusted TV cable produces early upshifts, slipping, and burnt clutches that look like a worn-out transmission.
4. 46RE: scan for governor pressure faults. The governor pressure solenoid and sensor are the parts the 46RH does not have. Erratic shift points, no upshift, or a shift schedule that changes with temperature belong here first.
5. Line pressure test. On either unit, a gauge reading of low line rise under load explains slipping better than a guess does.
6. Identify the valve body before ordering one. Sonnax splits its 46RE remanufactured valve bodies by year and sensor type, listing separate part numbers for 1999-and-earlier early-sensor units and 2000-and-later late-sensor units. Order the wrong side of that split and it will not work.

The fix, and what to replace while you are in there

On a 700R4 that is coming apart for burnt 3-4 clutches, the transmission has already told you what it needs. A full clutch and steel set, gaskets and seals, a filter, and a shift kit go in together. Our 700R4 Master Rebuild Kit bundles the frictions and steels, gaskets and seals, filter, shift kit, servo, and solenoids so the throttle-pressure and shift-feel side gets addressed at the same time as the clutches. Browse the full transmission rebuild kits collection for the 46RE equivalents by year range.

On a 46RE, the equivalent conversation is the governor pressure solenoid and sensor, plus the valve body if the bores are worn. A remanufactured 46RE valve body matched to your year and sensor type addresses the wear-related pressure control problems that a shift kit alone will not.

Replace-while-you-are-in-there list for either unit:

• Filter and pan gasket, every time, no exceptions
• Torque converter, if the converter clutch was slipping or the fluid was burnt
• Cooler flush or cooler replacement after any burnt-fluid failure
• 700R4: TV cable and bracket geometry, 2-4 band, servo, 3-4 clutch pack
• 46RE: Reverse band and rear servo, overdrive roller clutch, governor pressure solenoid and sensor, both pan-side electrical connectors
• Rear seal and output bushing while the unit is out

Shop the transmission solenoids collection for the electrical side of a 46RE job, and the valve bodies collection for either unit.

Cost and effort framing

Neither of these is a beginner rebuild, but the 700R4 is the more forgiving one. It has the deepest aftermarket support of any GM four-speed, its internals overlap heavily with the far more common 4L60-E, and Sonnax notes that many parts developed to improve 4L60-E performance and durability can also be used in the 700R4. Parts availability is effectively unlimited.

Plan on roughly 6 to 10 hours of shop labor for an R&R on either unit in a two-wheel-drive application, more with a transfer case. The rebuild itself is a full day of bench time for someone who has done one before, and considerably longer for someone who has not, largely because both units need endplay set correctly and the 700R4 needs band and servo travel checked. Difficulty: intermediate for the R&R, advanced for the internal rebuild.

The cost driver on a 700R4 is almost always the clutch and band package plus a converter. The cost driver on a 46RE is more often the valve body and governor pressure electronics, because those are the parts that wear and are not covered by a soft-parts kit.

Which one to choose

Choose the 700R4 if you are adding overdrive to a classic GM vehicle, want the steepest available first gear, or value parts availability and a simple installation without a computer. Sonnax rates the 700R4 as still very capable in many applications up to about 750 HP with the right internal upgrades, which is far more headroom than its reputation suggests.

Choose the 46RE if you already own a Dodge or Jeep that came with one. It is a good match for its factory applications, and moving it into anything else means solving bellhousing, controller, and driveline problems for no ratio advantage over the GM unit. If your 46RE is healthy, keep it. If you need more capacity behind a Dodge, the conversation moves to the 47RE and 48RE, not to a 700R4.

For more on the GM side, see our guide to 700R4 TV cable setup, which is the single adjustment that decides whether a 700R4 lives or burns. For the Chrysler side, our 46RE and 47RE complete guide covers identification and the differences within the family.

Frequently asked questions

Can a 46RE bolt to a Chevy engine, or a 700R4 to a Dodge?
Not without an adapter. These are different bellhousing patterns from different manufacturers. Adapters exist for many combinations, but you are then also solving driveshaft length, crossmember location, shifter linkage, and, for the 46RE, the governor pressure electronics. There is no ratio or strength reason to do it.

Is the 46RE electronically controlled like a 4L60-E?
Only partially. The 46RE uses a governor pressure solenoid and sensor for shift timing, which is what makes it the "RE" instead of the "RH." But it retains a mechanical throttle valve, and Sonnax still lists TV linkage shift-timing difficulty and throttle buzz among its symptoms. It is a hybrid, not a full electronic unit.

Why does my 700R4 keep burning the 3-4 clutch?
Most often it is low throttle pressure, not a defective clutch pack. Sonnax attributes it to the steel TV plunger wearing the aluminum plunger sleeve, letting throttle valve feed oil leak past and exhaust, combined with a weak OE spring, which produces low line rise, insufficient throttle pressure, and 3-4 clutch failure. Replacing the clutches without correcting throttle pressure just repeats the failure.

Sources

• Sonnax, 700-R4 (4L60) Performance Transmission Build Guide
• Sonnax, 4L60 Throttle Valve Plunger Valve Kit 77966-94K
• Sonnax, Chrysler 46RE Transmission (symptom list and remanufactured valve body identification)
• DieselHub, GM TH700R4 Transmission Specs & Ratios
• Moveras, Technical Specs - 46RE
• Transmission Repair Cost Guide, A518 / 46RE Specs & Updates