Subject: Whistle or Whine in Reverse or Lo 1 at Idle - THM 350C (MX3)
Model and Year: 1981 Corvette with THM 350C (MX3)
Source: Chevrolet Dealer Service Technical Bulletin
Bulletin No: 81-T-20
Section: VIIc
Date: July, 1981
TO: ALL CHEVROLET DEALERS
Some 350C transmissions in 1981 Corvettes and Camaros may emit a whistle or whine in Revers or Lo1 at base idle. This is caused by the valve body spacer plate hole shown in the illustration.
To correct noise, enlarge the hole using a No. 41 drill (.096) and remove any burrs formed on either side of the plate.
Use applicable labor operation.
Article ID: 984
Created: October 28, 2014
Last Updated: October 28, 2014
Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article/1981-corvette-service-bulletin-whistle-or-whine-in-reverse-or-lo-1-at-idle-thm-350c-mx3-984.html