Re: Overdrive Governor Adjustment

Posted by HH56 On 2022/8/27 16:40:50
The governor only has one set of contacts and it switches state at speed. EC is the normally closed contact while AD is the normally open contact. The little strap from the ground point at the screw goes to the common. At speed EC opens to disable that option and AD closes so the relay will power up and allow the OD to be prepared to engage.

I believe about the only way to adjust would be to rig up something like a drill motor to spin the governor at a constant speed and adjust the screw while it is spinning. It would also need some sort of tachometer and Amazon does sell a few inexpensive reflective tachs that should do the job. The difficulty is knowing what RPM would equal the speed you want it to change.

I believe one of the posters on this forum has a speedo repair shop and perhaps he would know what RPM would be needed to make the speedometer read in the 20mph range which is where Packard had most ODs wanting to come in. The governor and speedo both use the same drive gear off the trans shaft and while there might be a slight difference in governor vs speedo RPM because of the different speedo gears available for axle ratios they would be close. Packard did spec a several mph range when ODs would typically come in.

Without knowing the RPM needed it would be a difficult and time consuming trial and error job to try and guess where to adjust the screw.

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