Anyone who’s had a Mopar equipped with a four-speed knows the durability of Chrysler’s 833 transmission. The piece is so strong, in fact, that even GM and Ford racers of the late ’60s and into the ’70s often swapped one into their cars in the interest of reliability. Over the years, Chrysler made several versions of this tough manual transmission, varying the number of splines on the input shaft, input bearing sizes, and even the ratio of the gearing. 833s were originally produced with a cast-iron case, but later versions offered a lighter aluminum case and even an overdrive fourth gear. And while these transmissions have survived the test of time, many having never been rebuilt or resealed, most 833s are nearly 40 years old so it’s not uncommon for some problems to develop.
One such problem involves the input bearing of the transmission—especially with an aluminum case—and can be corrected by a modification to the input bearing retainer. While it is commonly known that the bearing retainer can crack, necessitating replacement, a somewhat less common problem is that the outer race of the input bearing itself can spin in the transmission case due to not enough interference between the two parts. The main symptom of this problem is a horrible shrieking noise, and if left uncorrected the transmission case will become trashed, necessitating a complete rebuild with a new case or a new transmission altogether.
Editor Bolig’s wife Paula must have really been revving her Dart Sport, likely showing the taillights to some unsuspecting driver of a Camaro or Mustang, because she experienced this problem with her transmission. Knowing how annoying it is to drive around with what Randy described as a “blood-curdling squeal” coming from under the car, we decided to attempt a modification to the bearing retainer and save the transmission. And while we might not deem this repair strong enough for a full-blown race application, for a moderately powered street car it works just fine.
By first removing the transmission, then the input-shaft bearing retainer itself, we drilled two holes in the retainer at the dimension of the outer race, then tapped the holes we drilled for set-screws to hold the outer race stationary. By threading ¼-inch set screws against the outer race of the input shaft bearing, then placing nuts on the set-screws to hold them in place, the outer race is held immobile in the case, allowing the bearing to perform its job properly and saving the transmission case from further damage. Although the transmission does need to be completely removed to perform this repair, otherwise it is straightforward and we’ve found it to work well. Now the only shrieking heard in the Dart Sport will be from passengers as Paula rows through the gears, but that’s a noise we like to hear! mm
1 Though modifying the input...
1 Though modifying the input shaft bearing retainer itself is straightforward and inexpensive, it does require completely removing the transmission. If you’re comfortable doing this yourself then this repair should be no problem.
2 With the transmission out...
2 With the transmission out of the car, the front bearing retainer can be removed from the case and marked to be drilled. The holes need to be positioned so the set screws will contact the outer race of the input shaft bearing.
3 Using a drill press to...
3 Using a drill press to keep the holes lined up and straight, we drilled two holes in the bearing retainer to the nominal size required for ¼-20 set screws. One set screw may be enough to hold the bearing in place, but we wanted to apply even pressure to both sides of the bearing.
4 Using a 1/4-20 tap, we...
4 Using a 1/4-20 tap, we tapped the holes to accept our set screws and cleaned all the metal shavings from the bearing retainer. We then reinstalled the retainer and then threaded the set screws into place, applying pressure against the outer bearing race. A new gasket is preferred, but silicone can work as well.
5 To ensure the set screws...
5 To ensure the set screws don’t back out, nuts can be installed and tightened against the bearing retainer. A bit of thread-locker can also be applied for extra insurance. With the repair made, the transmission is simply reinstalled into the car and should give many more years of service. The great thing about this repair is that it is cheap, saving the expense of a new transmission case.