Time: 1 hour
Tools: sockets, wrenches
Talent: novice
Bucks: about $120
Tip: be sure to order a grommet, seal and mounting nut set with the motor
Performance Improvement: it’s always nice to see where you’re going in the rain.
While You’re At It: this is a good time to install a wiper compartment cover available for 1973-1982 Corvettes.
When your windshield wiper motor quits (and, rest assured, it will eventually) it’s a fairly simple matter to replace it. It takes well under an hour and no special skills are required.
On 1968-1972 Corvettes with the wiper door cover, the first thing you’ll have to do is manually open it so you can gain access to the wiper compartment. Once open or if you have a 1973-1982 car, you can then unsnap the wiring harness that supplies power to the wiper motor. The wiper motor is secured to the firewall with three nuts on studs. Use a 3/8” socket to remove these nuts, being careful not to let them drop down into the engine compartment. The nut and washer retaining the bellcrank arm in the wiper compartment is removed next. Gently moving the bellcrank arm back and forth will free it from the wiper motor shaft.
When you receive the new wiper motor it will not have a washer pump or cover on it, or may come without mounting grommets or the nut for retaining the bellcrank arm. The gearbox cover and grommets can be swapped from the old unit to the new one. But the bellcrank arm retaining nut required for the new motor was a different size than the one removed from the old one in this instance. For this reason it’s a good idea to order new grommets, a seal and mounting nuts when you order the motor. If you’re lucky, a look in the spare nuts and bolts cans in the garage may unearth a nut of the right size and thread.
The machine screws holding the windshield washer pump or cover on the old motor are removed using a socket. The cover is then installed on the new motor using the same screws removed from the old unit. The new wiper motor may have an extra grounding tab, which has to be bent up and secured with one of the gearbox cover screws. The mounting grommets are also installed now.
A new wiper motor seal is then slipped over the shaft of the motor and the motor is reinstalled on the firewall, passing the shaft through the hole until the seal is firmly pressed to the both the firewall and the motor. The three retaining nuts are then installed and tightened using a socket. The bellcrank arm is keyed so it will only go on the shaft in the correct orientation. Wiggling it back and forth will help to seat it on the shaft.
The retaining nut and washer are installed on the shaft next and tightened. This is a good time to remove any debris (e.g., leaves) that may have gotten into the wiper compartment.
To finish the job, snap the wiring harness for the motor on next. The harness is keyed so it will only go on in the correct orientation. If you have a wiper compartment cover, reinstall it now. Switch your ignition to the accessory or on position, turn the wiper switch on to confirm proper operation and that’s all there is to it.
Note when purchasing a new windshield wiper motor
The motor is factory set in the park position. Do not bench test the motor or rotate the shaft before installation. This can cause damage to the motor and your Corvette, voiding your warranty, and you will not be able to return it. We cannot re-park your motor. Refer to your Corvette shop manual for proper installation instructions.
Photos and story by Tom Benford