Chrysler A-833 four speed manual transmissions — history, tech, and swap
Any transmission can expire, but Chrysler's A-833 4-speed is much less likely to do so than
other, more anemic models. When surgery is required, however, it is helpful (naturally) to have intimate knowledge of the patient and its problems. Knowing which internal organs can be transplanted is also useful.
To ensure the continued well-being of your Chrysler 4-speed, let's take a guided tour of the various versions produced, from the grandfather of performance Mopar gearboxes in 1964 up to today's aluminum youngsters. With the right input, maybe you can keep your trans out of intensive care.
It's the spring of 1962. Dodge's 413 Ramcharger and Plymouth's Super Stock are cleaning house at the nation's drag strips. The new but already legendary A-727 Torqueflite automatic transmission has made Chrysler the undisputed ruler of the S/SA class. In SIS, though, things aren't so rosy. The hard-shifting, ratio-short manual is proving to be somewhat less than the hot ticket for trophy gold. Something needs to be done, and fast.
Back in Highland Park, the drivetrain folks are burning the midnight oil. They desperately try the Warner Gear T-10 used by the Brand "C" and "F" boys, but it just can't handle the Max Wedge's MoPower. The die is cast and plans are made for an all-new gearbox that will be able to take the abuse of anything the engine boys can dish out. Unfortunately, designing an all-new gearbox takes something that Chrysler is short on: time.
For '63, Chrysler has no choice but to sell some cars with the T-10, mostly to counteract the street charisma of the 4-speed 406 and 409 cars. Still, Chrysler knows better than to sell 413s with the T-10, as this would result in blown-up boxes from coast to coast. The drag guys are still offered only the 3-speed.
|A-833 Transmission Gear Ratios||1st||2nd||3rd||4th|
|6-cyl (also 64-65 273, 74-75 318)||3.09||1.92||1.40||1.00|
|Fine-spline V8 (most pre-1971)||2.66||1.91||1.39||1.00|
|Coarse-spline V8 (1966-70)||2.65||1.93||1.39||1.00|
|Coarse-spline V8 (1971-74)||2.44||1.77||1.34||1.00|
|Road Race T/A; most 1971-74 fine spline||2.47||1.77||1.34||1.00|
|Overdrive (mid-1970s and newer)||3.09||1.67||1.00||0.73|
New model intro time, fall of 1963: At last! An all-new transmission, designated the A-833, is available in everything from 6-cylinder Valiants to rip-snortin' Max Wedges. Equipped with a standard-equipment Hurst-Campbell "Competition-Plus" shifter and exhibiting four fully synchronized forward speeds, it is the answer to our prayers. Built in Chrysler's Syracuse, New York, "New Process" gear division plant, it is (even in 1989), the largest, strongest and heaviest 4-gear passenger car transmission ever built.
Right from day one there are two distinct versions of this box: A-body (later to be used in F-bodies) and B-body (also to be found in later C- and E-bodies). Initially there are three main version-to-version differences: extension housing and mains haft length, low-gear ratio and rear-flange size. The A-car box, while every bit as strong as its larger cousin, carries a 3.09-to-1 low gear, designed to help launch small cars with even smaller mills.
For 1965 there is only one noteworthy upgrade: the 1-2 shifter fork is redesigned to ease second-gear powershifts.
In 1966, though, several important changes appear. First (and worst), the Hurst shifter is eliminated, replaced by a hollow-shaft Inland unit. Enthusiasts generally are in agreement that this is a giant step backward, but Joe Average likes the reverse lockout feature. Second, the ball-and-trunnion front U-joint flange is gone, replaced by a more typical sliding-spline yoke arrangement. A new speedometer pinion setup is introduced, which allows more precise calibration (earlier ones were on a small cable-mounted adapter; starting in 1966 they use larger pinions and adapters). Also, except for the very early production cars, the 8-cylinder A-bodies now come with the B-car's 2.66 first-gear ratio.
Most importantly, another gearset is incorporated for the new Street Hemi models, featuring Oilite™ bushings lining each gear and revised gear tooth angles for more strength. Hemi cars also receive a new, larger main drive pinion (input shaft), utilizing a larger (No. 308) bearing, bearing retainer and new coarse-spline clutch disc. A unique, beefier clutch release bearing completes the package.
For 1967, a major flaw is corrected: The synchronizers and brass stop rings are redesigned to eliminate stop ring breakage on hard shifts. Luckily, these upgraded synchros can be retrofitted into the earlier transmissions. (This basic synchro design has survived right up through 1989!)
Then the 1968 models hit the streets. Gearjammers coast to coast are dismayed to find that the new Road Runner muscle car is stuck with the same lousy Inland shifter. Soon, though, Chrysler seems to have had it "up to here" with the complaints, because shortly after the introduction, the Hurst shifter reappears across the board, now all dressed up with a new simulated-walnut shift knob.
The next noteworthy revisions come in 1970. First, a new 2.47-low close-ratio gearset is introduced for the T/A and AAR E-bodies (which later becomes standard in most 4-speed cars). Then the outrageous "pistol grip" shifter is released (this has since become a much-sought-after restoration item). It consists of a beefy, flat chrome stick with two woodgrain grips attached to each side and a shift-pattern logo cap on top. Cars equipped with this shifter also enjoy a new set of transmission levers, punched with an extra set of holes for those who want extra-short-throw shifting.
The major change for 1971 (actually a late-'70 running change) is a redesign of the side cover and interlock mechanism. New sheet-steel interlock levers replace the old pin-and-balls type. The setup requires new internal shift forks as well, and they are now made of cast steel instead of brass. Note, also, that the entire side cover setups can be interchanged either way. This is useful, since the '70-down type is generally regarded as better for drag racing and serious abuse.
Another event for 1971: Chrysler's Performance Parts Services releases aluminum cases and extensions to the general public. A few had been made for the '65 drag Hemis, but they were, for all practical purposes, nonexistent.
Also for '71, 440 and Hemi cars with the coarse-pitch gears receive a new gearset with a 2.44 low. This applies only to cars with these engines, and they continue to feature the bushed mains haft gears and coarsespline clutch input.
Through the early '70s, Chrysler sort of coasts with the A-833, no major revisions being introduced. Is that bad? Not really. Can you improve upon perfection?
1976 finds us well into the gas shortage era, so Chrysler responds by introducing two gas mileage champs: the Dart Lite and Feather Duster. Lightened, as they are, with several aluminum panels and other "dietized" components, the major new mechanical piece is a revised A-833 with drastically different gear ratios. The 3.09 first gear of the former 6-cylinder cars remains intact, but third gear was changed from 1.40- to 0.73-to-1. That's right, third is overdrive and fourth is direct. A simple flip of the gear lever on the side cover gives the driver the illusion of three normal speeds and a fourth that is overdrive.
This transmission also has undergone other revisions: a new superlarge front bearing retainer is used, one even larger than the old "Hemi" models. This eases servicing as the main drive pinion is now removable from the front. The case and extension are cast in aluminum, but the main case isn't the same as the old performance unit. The redesigned box bushings pressed in rigidly support the countershaft, but the OD unit contains no such bushings. In fact, the countershaft holes are reamed oversize, which allows the countershaft to "float" (which is supposedly for "gear rattle suppression"). It then requires a shorter countershaft and cupped plug at the front to prevent oil leakage.
Many swaps are feasible within the Chrysler manual transmission family.
First, all '70-and-up 8-cylinder clutch housings are drilled for both 3- speed and 4-speed bolt patterns. Except for the '65-down cars, nearly all models used the large output-shaft spline, the exception being some late '70s Slant Six F- and A-bodies. There were only two rear motor mount locations, and crossmembers were available to accommodate each. The bellhousings generally contained enough "meat" to allow remachining for either the Feather Duster or Hemi-size bearing retainer.
When buying a used box, make sure it has the shifter mounting bosses where you need 'em for your particular vehicle. Naturally, you should also be sure to select a transmission that will mate with the clutch disc you'll be using, and be sure to have the correct release (throw-out) bearing to fit your box's front bearing retainer. The mainshaft rear spline (output shaft) must also mate with your prop shaft, but, as we've said, that is generally not a problem area.
The accompanying photos should help guide you through some of the more common swaps, differences, repairs and upgrades and clue you in as to what to look for at the local boneyards and swap meets. You'll note that we've pretty much ignored the one-off race pieces-such as the slickshift synchroless conversion and the full race "red-stripe" gearsets--choosing instead to concentrate on the more readily available, mass-produced parts.
If you're tired of being shiftless and winning automatically, get out the tools and bolt in another gear!